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* [PATCH v3 00/24] LSM: Module stacking for AppArmor
@ 2019-06-21 18:52 Casey Schaufler
  2019-06-21 18:52 ` [PATCH v3 01/24] LSM: Infrastructure management of the superblock Casey Schaufler
                   ` (23 more replies)
  0 siblings, 24 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

This patchset provides the changes required for
the AppArmor security module to stack safely with any other.

v3: Incorporate feedback from v2
    - Make lsmblob parameter and variable names more
      meaningful, changing "le" and "l" to "blob".
    - Improve consistency of constant naming.
    - Do more sanity checking during LSM initialization.
    - Be a bit clearer about what is temporary scaffolding.
    - Rather than clutter security_getpeersec_dgram with
      otherwise unnecessary checks remove the apparmor
      stub, which does nothing useful.

Patches 0001-0003 complete the process of moving managment
of security blobs that might be shared from the individual
modules to the infrastructure.

Patches 0004-0014 replace system use of a "secid" with
a structure "lsmblob" containing information from the
security modules to be held and reused later. At this
point lsmblob contains an array of u32 secids, one "slot"
for each of the security modules compiled into the
kernel that used secids. A "slot" is allocated when
a security module registers a hook for one of the interfaces
that uses a secid or a security context. The infrastructure
is changed to use the slot number to pass the correct
secid to or from the security module hooks.

It is important that the lsmblob be a fixed size entity
that does not have to be allocated. Several of the places
where it is used would have performance and/or locking
issues with dynamic allocation.

Patch 0015 provides a mechanism for a process to
identify which security module's hooks should be used
when displaying or converting a security context string.
A new interface /proc/.../attr/display contains the name
of the security module to show. Reading from this file
will present the name of the module, while writing to
it will set the value. Only names of active security
modules are accepted. Internally, the name is translated
to the appropriate "slot" number for the module which
is then stored in the task security blob.

Patch 0016 Starts the process of changing how a security
context is represented. Since it is possible for a
security context to have been generated by more than one
security module it is now necessary to note which module
created a security context so that the correct "release"
hook can be called. There are several places where the
module that created a security context cannot be inferred.

This is achieved by introducing a "lsmcontext" structure
which contains the context string, its length and the
"slot" number of the security module that created it.
The security_release_secctx() interface is changed,
replacing the (string,len) pointer pair with a lsmcontext
pointer.

Patches 0012-0021 convert the security interfaces from
(string,len) pointer pairs to a lsmcontext pointer.
The slot number identifying the creating module is
added by the infrastructure. Where the security context
is stored for extended periods the data type is changed.

Patch 0022 provides a simple way for a security module
to know its "slot" number. The security_add_hooks()
initialization function returns the slot number, and the
security module need but stash the value for later use,
as is required by the Netlabel subsystem. The Netlabel
code is converted to save lsmblob structures instead
of secids in Patch 0023.

Finally, with all interference on the AppArmor hooks
removed, Patch 0024 removes the exclusive bit from
AppArmor. An unnecessary stub hook was also removed.

The Ubuntu project is using an earlier version of
this patchset in their distribution to enable stacking
for containers.

Performance measurements to date have the change
within the "noise". Better benchmarks are in the
works.

https://github.com/cschaufler/lsm-stacking.git#stack-5.2-v3-apparmor

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 drivers/android/binder.c                |  24 +-
 fs/kernfs/dir.c                         |   5 +-
 fs/kernfs/inode.c                       |  35 ++-
 fs/kernfs/kernfs-internal.h             |   3 +-
 fs/nfs/nfs4proc.c                       |  22 +-
 fs/nfsd/nfs4xdr.c                       |  20 +-
 fs/proc/base.c                          |   1 +
 include/linux/cred.h                    |   3 +-
 include/linux/lsm_hooks.h               |   8 +-
 include/linux/security.h                | 165 ++++++++++---
 include/net/af_unix.h                   |   2 +-
 include/net/netlabel.h                  |   8 +-
 include/net/scm.h                       |  14 +-
 kernel/audit.c                          |  34 +--
 kernel/audit.h                          |   9 +-
 kernel/auditfilter.c                    |   6 +-
 kernel/auditsc.c                        |  79 +++----
 kernel/cred.c                           |  12 +-
 net/ipv4/cipso_ipv4.c                   |   6 +-
 net/ipv4/ip_sockglue.c                  |  12 +-
 net/netfilter/nf_conntrack_netlink.c    |  20 +-
 net/netfilter/nf_conntrack_standalone.c |  11 +-
 net/netfilter/nfnetlink_queue.c         |  26 ++-
 net/netfilter/nft_meta.c                |  13 +-
 net/netfilter/xt_SECMARK.c              |   5 +-
 net/netlabel/netlabel_kapi.c            |   6 +-
 net/netlabel/netlabel_unlabeled.c       |  95 ++++----
 net/netlabel/netlabel_unlabeled.h       |   2 +-
 net/netlabel/netlabel_user.c            |  13 +-
 net/netlabel/netlabel_user.h            |   6 +-
 net/unix/af_unix.c                      |   6 +-
 security/apparmor/include/net.h         |   6 +-
 security/apparmor/lsm.c                 |  66 ++----
 security/integrity/ima/ima.h            |  14 +-
 security/integrity/ima/ima_api.c        |   9 +-
 security/integrity/ima/ima_appraise.c   |   6 +-
 security/integrity/ima/ima_main.c       |  36 +--
 security/integrity/ima/ima_policy.c     |  19 +-
 security/security.c                     | 396 ++++++++++++++++++++++++++++----
 security/selinux/hooks.c                | 164 ++++++-------
 security/selinux/include/objsec.h       |  18 ++
 security/selinux/include/security.h     |   1 +
 security/selinux/netlabel.c             |  25 +-
 security/selinux/ss/services.c          |   7 +-
 security/smack/smack.h                  |  19 ++
 security/smack/smack_lsm.c              | 154 ++++++-------
 security/smack/smack_netfilter.c        |   8 +-
 security/smack/smackfs.c                |  10 +-
 48 files changed, 1017 insertions(+), 612 deletions(-)

^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 01/24] LSM: Infrastructure management of the superblock
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-24 18:31   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 02/24] LSM: Infrastructure management of the sock security Casey Schaufler
                   ` (22 subsequent siblings)
  23 siblings, 1 reply; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Move management of the superblock->sb_security blob out
of the individual security modules and into the security
infrastructure. Instead of allocating the blobs from within
the modules the modules tell the infrastructure how much
space is required, and the space is allocated there.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h         |  1 +
 security/security.c               | 46 ++++++++++++++++++++----
 security/selinux/hooks.c          | 58 ++++++++++++-------------------
 security/selinux/include/objsec.h |  6 ++++
 security/selinux/ss/services.c    |  3 +-
 security/smack/smack.h            |  6 ++++
 security/smack/smack_lsm.c        | 35 +++++--------------
 7 files changed, 85 insertions(+), 70 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index a240a3fc5fc4..f9222a04968d 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2047,6 +2047,7 @@ struct lsm_blob_sizes {
 	int	lbs_cred;
 	int	lbs_file;
 	int	lbs_inode;
+	int	lbs_superblock;
 	int	lbs_ipc;
 	int	lbs_msg_msg;
 	int	lbs_task;
diff --git a/security/security.c b/security/security.c
index 23cbb1a295a3..550988a0f024 100644
--- a/security/security.c
+++ b/security/security.c
@@ -172,6 +172,7 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed)
 	lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode);
 	lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc);
 	lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg);
+	lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock);
 	lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task);
 }
 
@@ -300,12 +301,13 @@ static void __init ordered_lsm_init(void)
 	for (lsm = ordered_lsms; *lsm; lsm++)
 		prepare_lsm(*lsm);
 
-	init_debug("cred blob size     = %d\n", blob_sizes.lbs_cred);
-	init_debug("file blob size     = %d\n", blob_sizes.lbs_file);
-	init_debug("inode blob size    = %d\n", blob_sizes.lbs_inode);
-	init_debug("ipc blob size      = %d\n", blob_sizes.lbs_ipc);
-	init_debug("msg_msg blob size  = %d\n", blob_sizes.lbs_msg_msg);
-	init_debug("task blob size     = %d\n", blob_sizes.lbs_task);
+	init_debug("cred blob size       = %d\n", blob_sizes.lbs_cred);
+	init_debug("file blob size       = %d\n", blob_sizes.lbs_file);
+	init_debug("inode blob size      = %d\n", blob_sizes.lbs_inode);
+	init_debug("ipc blob size        = %d\n", blob_sizes.lbs_ipc);
+	init_debug("msg_msg blob size    = %d\n", blob_sizes.lbs_msg_msg);
+	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
+	init_debug("task blob size       = %d\n", blob_sizes.lbs_task);
 
 	/*
 	 * Create any kmem_caches needed for blobs
@@ -603,6 +605,27 @@ static void __init lsm_early_task(struct task_struct *task)
 		panic("%s: Early task alloc failed.\n", __func__);
 }
 
+/**
+ * lsm_superblock_alloc - allocate a composite superblock blob
+ * @sb: the superblock that needs a blob
+ *
+ * Allocate the superblock blob for all the modules
+ *
+ * Returns 0, or -ENOMEM if memory can't be allocated.
+ */
+int lsm_superblock_alloc(struct super_block *sb)
+{
+	if (blob_sizes.lbs_superblock == 0) {
+		sb->s_security = NULL;
+		return 0;
+	}
+
+	sb->s_security = kzalloc(blob_sizes.lbs_superblock, GFP_KERNEL);
+	if (sb->s_security == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
 /*
  * Hook list operation macros.
  *
@@ -776,12 +799,21 @@ int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *
 
 int security_sb_alloc(struct super_block *sb)
 {
-	return call_int_hook(sb_alloc_security, 0, sb);
+	int rc = lsm_superblock_alloc(sb);
+
+	if (unlikely(rc))
+		return rc;
+	rc = call_int_hook(sb_alloc_security, 0, sb);
+	if (unlikely(rc))
+		security_sb_free(sb);
+	return rc;
 }
 
 void security_sb_free(struct super_block *sb)
 {
 	call_void_hook(sb_free_security, sb);
+	kfree(sb->s_security);
+	sb->s_security = NULL;
 }
 
 void security_free_mnt_opts(void **mnt_opts)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 1d0b37af2444..7478d8eda00a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -335,7 +335,7 @@ static void inode_free_security(struct inode *inode)
 
 	if (!isec)
 		return;
-	sbsec = inode->i_sb->s_security;
+	sbsec = selinux_superblock(inode->i_sb);
 	/*
 	 * As not all inode security structures are in a list, we check for
 	 * empty list outside of the lock to make sure that we won't waste
@@ -366,11 +366,7 @@ static int file_alloc_security(struct file *file)
 
 static int superblock_alloc_security(struct super_block *sb)
 {
-	struct superblock_security_struct *sbsec;
-
-	sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
-	if (!sbsec)
-		return -ENOMEM;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 
 	mutex_init(&sbsec->lock);
 	INIT_LIST_HEAD(&sbsec->isec_head);
@@ -379,18 +375,10 @@ static int superblock_alloc_security(struct super_block *sb)
 	sbsec->sid = SECINITSID_UNLABELED;
 	sbsec->def_sid = SECINITSID_FILE;
 	sbsec->mntpoint_sid = SECINITSID_UNLABELED;
-	sb->s_security = sbsec;
 
 	return 0;
 }
 
-static void superblock_free_security(struct super_block *sb)
-{
-	struct superblock_security_struct *sbsec = sb->s_security;
-	sb->s_security = NULL;
-	kfree(sbsec);
-}
-
 struct selinux_mnt_opts {
 	const char *fscontext, *context, *rootcontext, *defcontext;
 };
@@ -507,7 +495,7 @@ static int selinux_is_genfs_special_handling(struct super_block *sb)
 
 static int selinux_is_sblabel_mnt(struct super_block *sb)
 {
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 
 	/*
 	 * IMPORTANT: Double-check logic in this function when adding a new
@@ -535,7 +523,7 @@ static int selinux_is_sblabel_mnt(struct super_block *sb)
 
 static int sb_finish_set_opts(struct super_block *sb)
 {
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 	struct dentry *root = sb->s_root;
 	struct inode *root_inode = d_backing_inode(root);
 	int rc = 0;
@@ -648,7 +636,7 @@ static int selinux_set_mnt_opts(struct super_block *sb,
 				unsigned long *set_kern_flags)
 {
 	const struct cred *cred = current_cred();
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 	struct dentry *root = sbsec->sb->s_root;
 	struct selinux_mnt_opts *opts = mnt_opts;
 	struct inode_security_struct *root_isec;
@@ -881,8 +869,8 @@ static int selinux_set_mnt_opts(struct super_block *sb,
 static int selinux_cmp_sb_context(const struct super_block *oldsb,
 				    const struct super_block *newsb)
 {
-	struct superblock_security_struct *old = oldsb->s_security;
-	struct superblock_security_struct *new = newsb->s_security;
+	struct superblock_security_struct *old = selinux_superblock(oldsb);
+	struct superblock_security_struct *new = selinux_superblock(newsb);
 	char oldflags = old->flags & SE_MNTMASK;
 	char newflags = new->flags & SE_MNTMASK;
 
@@ -914,8 +902,9 @@ static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
 					unsigned long *set_kern_flags)
 {
 	int rc = 0;
-	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
-	struct superblock_security_struct *newsbsec = newsb->s_security;
+	const struct superblock_security_struct *oldsbsec =
+						selinux_superblock(oldsb);
+	struct superblock_security_struct *newsbsec = selinux_superblock(newsb);
 
 	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
 	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
@@ -1085,7 +1074,7 @@ static int show_sid(struct seq_file *m, u32 sid)
 
 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
 {
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 	int rc;
 
 	if (!(sbsec->flags & SE_SBINITIALIZED))
@@ -1377,7 +1366,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 	if (isec->sclass == SECCLASS_FILE)
 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
 
-	sbsec = inode->i_sb->s_security;
+	sbsec = selinux_superblock(inode->i_sb);
 	if (!(sbsec->flags & SE_SBINITIALIZED)) {
 		/* Defer initialization until selinux_complete_init,
 		   after the initial policy is loaded and the security
@@ -1767,7 +1756,8 @@ selinux_determine_inode_label(const struct task_security_struct *tsec,
 				 const struct qstr *name, u16 tclass,
 				 u32 *_new_isid)
 {
-	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
+	const struct superblock_security_struct *sbsec =
+						selinux_superblock(dir->i_sb);
 
 	if ((sbsec->flags & SE_SBINITIALIZED) &&
 	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
@@ -1798,7 +1788,7 @@ static int may_create(struct inode *dir,
 	int rc;
 
 	dsec = inode_security(dir);
-	sbsec = dir->i_sb->s_security;
+	sbsec = selinux_superblock(dir->i_sb);
 
 	sid = tsec->sid;
 
@@ -1947,7 +1937,7 @@ static int superblock_has_perm(const struct cred *cred,
 	struct superblock_security_struct *sbsec;
 	u32 sid = cred_sid(cred);
 
-	sbsec = sb->s_security;
+	sbsec = selinux_superblock(sb);
 	return avc_has_perm(&selinux_state,
 			    sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
 }
@@ -2578,11 +2568,6 @@ static int selinux_sb_alloc_security(struct super_block *sb)
 	return superblock_alloc_security(sb);
 }
 
-static void selinux_sb_free_security(struct super_block *sb)
-{
-	superblock_free_security(sb);
-}
-
 static inline int opt_len(const char *s)
 {
 	bool open_quote = false;
@@ -2653,7 +2638,7 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
 static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
 {
 	struct selinux_mnt_opts *opts = mnt_opts;
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 	u32 sid;
 	int rc;
 
@@ -2877,7 +2862,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
 	int rc;
 	char *context;
 
-	sbsec = dir->i_sb->s_security;
+	sbsec = selinux_superblock(dir->i_sb);
 
 	newsid = tsec->create_sid;
 
@@ -3115,7 +3100,7 @@ static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
 		return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
 	}
 
-	sbsec = inode->i_sb->s_security;
+	sbsec = selinux_superblock(inode->i_sb);
 	if (!(sbsec->flags & SBLABEL_MNT))
 		return -EOPNOTSUPP;
 
@@ -3296,13 +3281,14 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name,
 				     const void *value, size_t size, int flags)
 {
 	struct inode_security_struct *isec = inode_security_novalidate(inode);
-	struct superblock_security_struct *sbsec = inode->i_sb->s_security;
+	struct superblock_security_struct *sbsec;
 	u32 newsid;
 	int rc;
 
 	if (strcmp(name, XATTR_SELINUX_SUFFIX))
 		return -EOPNOTSUPP;
 
+	sbsec = selinux_superblock(inode->i_sb);
 	if (!(sbsec->flags & SBLABEL_MNT))
 		return -EOPNOTSUPP;
 
@@ -6647,6 +6633,7 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
 	.lbs_inode = sizeof(struct inode_security_struct),
 	.lbs_ipc = sizeof(struct ipc_security_struct),
 	.lbs_msg_msg = sizeof(struct msg_security_struct),
+	.lbs_superblock = sizeof(struct superblock_security_struct),
 };
 
 static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
@@ -6675,7 +6662,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param),
 
 	LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
-	LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),
 	LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
 	LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
 	LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index 231262d8eac9..d08d7e5d2f93 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -188,4 +188,10 @@ static inline struct ipc_security_struct *selinux_ipc(
 	return ipc->security + selinux_blob_sizes.lbs_ipc;
 }
 
+static inline struct superblock_security_struct *selinux_superblock(
+					const struct super_block *superblock)
+{
+	return superblock->s_security + selinux_blob_sizes.lbs_superblock;
+}
+
 #endif /* _SELINUX_OBJSEC_H_ */
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index ec62918521b1..e3f5d6aece66 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -50,6 +50,7 @@
 #include <linux/audit.h>
 #include <linux/mutex.h>
 #include <linux/vmalloc.h>
+#include <linux/lsm_hooks.h>
 #include <net/netlabel.h>
 
 #include "flask.h"
@@ -2751,7 +2752,7 @@ int security_fs_use(struct selinux_state *state, struct super_block *sb)
 	struct sidtab *sidtab;
 	int rc = 0;
 	struct ocontext *c;
-	struct superblock_security_struct *sbsec = sb->s_security;
+	struct superblock_security_struct *sbsec = selinux_superblock(sb);
 	const char *fstype = sb->s_type->name;
 
 	read_lock(&state->ss->policy_rwlock);
diff --git a/security/smack/smack.h b/security/smack/smack.h
index cf52af77d15e..caecbcba9942 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -375,6 +375,12 @@ static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc)
 	return ipc->security + smack_blob_sizes.lbs_ipc;
 }
 
+static inline struct superblock_smack *smack_superblock(
+					const struct super_block *superblock)
+{
+	return superblock->s_security + smack_blob_sizes.lbs_superblock;
+}
+
 /*
  * Is the directory transmuting?
  */
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 5c1613519d5a..807eff2ccce9 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -540,12 +540,7 @@ static int smack_syslog(int typefrom_file)
  */
 static int smack_sb_alloc_security(struct super_block *sb)
 {
-	struct superblock_smack *sbsp;
-
-	sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
-
-	if (sbsp == NULL)
-		return -ENOMEM;
+	struct superblock_smack *sbsp = smack_superblock(sb);
 
 	sbsp->smk_root = &smack_known_floor;
 	sbsp->smk_default = &smack_known_floor;
@@ -554,22 +549,10 @@ static int smack_sb_alloc_security(struct super_block *sb)
 	/*
 	 * SMK_SB_INITIALIZED will be zero from kzalloc.
 	 */
-	sb->s_security = sbsp;
 
 	return 0;
 }
 
-/**
- * smack_sb_free_security - free a superblock blob
- * @sb: the superblock getting the blob
- *
- */
-static void smack_sb_free_security(struct super_block *sb)
-{
-	kfree(sb->s_security);
-	sb->s_security = NULL;
-}
-
 struct smack_mnt_opts {
 	const char *fsdefault, *fsfloor, *fshat, *fsroot, *fstransmute;
 };
@@ -781,7 +764,7 @@ static int smack_set_mnt_opts(struct super_block *sb,
 {
 	struct dentry *root = sb->s_root;
 	struct inode *inode = d_backing_inode(root);
-	struct superblock_smack *sp = sb->s_security;
+	struct superblock_smack *sp = smack_superblock(sb);
 	struct inode_smack *isp;
 	struct smack_known *skp;
 	struct smack_mnt_opts *opts = mnt_opts;
@@ -880,7 +863,7 @@ static int smack_set_mnt_opts(struct super_block *sb,
  */
 static int smack_sb_statfs(struct dentry *dentry)
 {
-	struct superblock_smack *sbp = dentry->d_sb->s_security;
+	struct superblock_smack *sbp = smack_superblock(dentry->d_sb);
 	int rc;
 	struct smk_audit_info ad;
 
@@ -917,7 +900,7 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm)
 	if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
 		return 0;
 
-	sbsp = inode->i_sb->s_security;
+	sbsp = smack_superblock(inode->i_sb);
 	if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) &&
 	    isp->smk_task != sbsp->smk_root)
 		return 0;
@@ -1168,7 +1151,7 @@ static int smack_inode_rename(struct inode *old_inode,
  */
 static int smack_inode_permission(struct inode *inode, int mask)
 {
-	struct superblock_smack *sbsp = inode->i_sb->s_security;
+	struct superblock_smack *sbsp = smack_superblock(inode->i_sb);
 	struct smk_audit_info ad;
 	int no_block = mask & MAY_NOT_BLOCK;
 	int rc;
@@ -1410,7 +1393,7 @@ static int smack_inode_removexattr(struct dentry *dentry, const char *name)
 	 */
 	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
 		struct super_block *sbp = dentry->d_sb;
-		struct superblock_smack *sbsp = sbp->s_security;
+		struct superblock_smack *sbsp = smack_superblock(sbp);
 
 		isp->smk_inode = sbsp->smk_default;
 	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0)
@@ -1680,7 +1663,7 @@ static int smack_mmap_file(struct file *file,
 	isp = smack_inode(file_inode(file));
 	if (isp->smk_mmap == NULL)
 		return 0;
-	sbsp = file_inode(file)->i_sb->s_security;
+	sbsp = smack_superblock(file_inode(file)->i_sb);
 	if (sbsp->smk_flags & SMK_SB_UNTRUSTED &&
 	    isp->smk_mmap != sbsp->smk_root)
 		return -EACCES;
@@ -3288,7 +3271,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
 		goto unlockandout;
 
 	sbp = inode->i_sb;
-	sbsp = sbp->s_security;
+	sbsp = smack_superblock(sbp);
 	/*
 	 * We're going to use the superblock default label
 	 * if there's no label on the file.
@@ -4575,6 +4558,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
 	.lbs_inode = sizeof(struct inode_smack),
 	.lbs_ipc = sizeof(struct smack_known *),
 	.lbs_msg_msg = sizeof(struct smack_known *),
+	.lbs_superblock = sizeof(struct superblock_smack),
 };
 
 static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
@@ -4586,7 +4570,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param),
 
 	LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
-	LSM_HOOK_INIT(sb_free_security, smack_sb_free_security),
 	LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
 	LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
 	LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 02/24] LSM: Infrastructure management of the sock security
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
  2019-06-21 18:52 ` [PATCH v3 01/24] LSM: Infrastructure management of the superblock Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-24 18:33   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 03/24] LSM: Infrastructure management of the key blob Casey Schaufler
                   ` (21 subsequent siblings)
  23 siblings, 1 reply; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Move management of the sock->sk_security blob out
of the individual security modules and into the security
infrastructure. Instead of allocating the blobs from within
the modules the modules tell the infrastructure how much
space is required, and the space is allocated there.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h         |  1 +
 security/apparmor/include/net.h   |  6 ++-
 security/apparmor/lsm.c           | 38 ++++-----------
 security/security.c               | 36 +++++++++++++-
 security/selinux/hooks.c          | 78 +++++++++++++++----------------
 security/selinux/include/objsec.h |  5 ++
 security/selinux/netlabel.c       | 23 ++++-----
 security/smack/smack.h            |  5 ++
 security/smack/smack_lsm.c        | 64 ++++++++++++-------------
 security/smack/smack_netfilter.c  |  8 ++--
 10 files changed, 144 insertions(+), 120 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index f9222a04968d..b353482ea348 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2047,6 +2047,7 @@ struct lsm_blob_sizes {
 	int	lbs_cred;
 	int	lbs_file;
 	int	lbs_inode;
+	int	lbs_sock;
 	int	lbs_superblock;
 	int	lbs_ipc;
 	int	lbs_msg_msg;
diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h
index 7334ac966d01..adac04e3b3cc 100644
--- a/security/apparmor/include/net.h
+++ b/security/apparmor/include/net.h
@@ -55,7 +55,11 @@ struct aa_sk_ctx {
 	struct aa_label *peer;
 };
 
-#define SK_CTX(X) ((X)->sk_security)
+static inline struct aa_sk_ctx *aa_sock(const struct sock *sk)
+{
+	return sk->sk_security + apparmor_blob_sizes.lbs_sock;
+}
+
 #define SOCK_ctx(X) SOCK_INODE(X)->i_security
 #define DEFINE_AUDIT_NET(NAME, OP, SK, F, T, P)				  \
 	struct lsm_network_audit NAME ## _net = { .sk = (SK),		  \
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 49d664ddff44..2716e7731279 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -757,33 +757,15 @@ static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo
 	return error;
 }
 
-/**
- * apparmor_sk_alloc_security - allocate and attach the sk_security field
- */
-static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
-{
-	struct aa_sk_ctx *ctx;
-
-	ctx = kzalloc(sizeof(*ctx), flags);
-	if (!ctx)
-		return -ENOMEM;
-
-	SK_CTX(sk) = ctx;
-
-	return 0;
-}
-
 /**
  * apparmor_sk_free_security - free the sk_security field
  */
 static void apparmor_sk_free_security(struct sock *sk)
 {
-	struct aa_sk_ctx *ctx = SK_CTX(sk);
+	struct aa_sk_ctx *ctx = aa_sock(sk);
 
-	SK_CTX(sk) = NULL;
 	aa_put_label(ctx->label);
 	aa_put_label(ctx->peer);
-	kfree(ctx);
 }
 
 /**
@@ -792,8 +774,8 @@ static void apparmor_sk_free_security(struct sock *sk)
 static void apparmor_sk_clone_security(const struct sock *sk,
 				       struct sock *newsk)
 {
-	struct aa_sk_ctx *ctx = SK_CTX(sk);
-	struct aa_sk_ctx *new = SK_CTX(newsk);
+	struct aa_sk_ctx *ctx = aa_sock(sk);
+	struct aa_sk_ctx *new = aa_sock(newsk);
 
 	new->label = aa_get_label(ctx->label);
 	new->peer = aa_get_label(ctx->peer);
@@ -844,7 +826,7 @@ static int apparmor_socket_post_create(struct socket *sock, int family,
 		label = aa_get_current_label();
 
 	if (sock->sk) {
-		struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
+		struct aa_sk_ctx *ctx = aa_sock(sock->sk);
 
 		aa_put_label(ctx->label);
 		ctx->label = aa_get_label(label);
@@ -1029,7 +1011,7 @@ static int apparmor_socket_shutdown(struct socket *sock, int how)
  */
 static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
-	struct aa_sk_ctx *ctx = SK_CTX(sk);
+	struct aa_sk_ctx *ctx = aa_sock(sk);
 
 	if (!skb->secmark)
 		return 0;
@@ -1042,7 +1024,7 @@ static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 
 static struct aa_label *sk_peer_label(struct sock *sk)
 {
-	struct aa_sk_ctx *ctx = SK_CTX(sk);
+	struct aa_sk_ctx *ctx = aa_sock(sk);
 
 	if (ctx->peer)
 		return ctx->peer;
@@ -1126,7 +1108,7 @@ static int apparmor_socket_getpeersec_dgram(struct socket *sock,
  */
 static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
 {
-	struct aa_sk_ctx *ctx = SK_CTX(sk);
+	struct aa_sk_ctx *ctx = aa_sock(sk);
 
 	if (!ctx->label)
 		ctx->label = aa_get_current_label();
@@ -1136,7 +1118,7 @@ static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
 static int apparmor_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 				      struct request_sock *req)
 {
-	struct aa_sk_ctx *ctx = SK_CTX(sk);
+	struct aa_sk_ctx *ctx = aa_sock(sk);
 
 	if (!skb->secmark)
 		return 0;
@@ -1153,6 +1135,7 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
 	.lbs_cred = sizeof(struct aa_task_ctx *),
 	.lbs_file = sizeof(struct aa_file_ctx),
 	.lbs_task = sizeof(struct aa_task_ctx),
+	.lbs_sock = sizeof(struct aa_sk_ctx),
 };
 
 static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
@@ -1189,7 +1172,6 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
 	LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
 
-	LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security),
 	LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
 	LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),
 
@@ -1581,7 +1563,7 @@ static unsigned int apparmor_ip_postroute(void *priv,
 	if (sk == NULL)
 		return NF_ACCEPT;
 
-	ctx = SK_CTX(sk);
+	ctx = aa_sock(sk);
 	if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
 				    skb->secmark, sk))
 		return NF_ACCEPT;
diff --git a/security/security.c b/security/security.c
index 550988a0f024..e32b7180282e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -32,6 +32,7 @@
 #include <linux/string.h>
 #include <linux/msg.h>
 #include <net/flow.h>
+#include <net/sock.h>
 
 #define MAX_LSM_EVM_XATTR	2
 
@@ -172,6 +173,7 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed)
 	lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode);
 	lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc);
 	lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg);
+	lsm_set_blob_size(&needed->lbs_sock, &blob_sizes.lbs_sock);
 	lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock);
 	lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task);
 }
@@ -306,6 +308,7 @@ static void __init ordered_lsm_init(void)
 	init_debug("inode blob size      = %d\n", blob_sizes.lbs_inode);
 	init_debug("ipc blob size        = %d\n", blob_sizes.lbs_ipc);
 	init_debug("msg_msg blob size    = %d\n", blob_sizes.lbs_msg_msg);
+	init_debug("sock blob size       = %d\n", blob_sizes.lbs_sock);
 	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
 	init_debug("task blob size       = %d\n", blob_sizes.lbs_task);
 
@@ -605,6 +608,28 @@ static void __init lsm_early_task(struct task_struct *task)
 		panic("%s: Early task alloc failed.\n", __func__);
 }
 
+/**
+ * lsm_sock_alloc - allocate a composite sock blob
+ * @sock: the sock that needs a blob
+ * @priority: allocation mode
+ *
+ * Allocate the sock blob for all the modules
+ *
+ * Returns 0, or -ENOMEM if memory can't be allocated.
+ */
+int lsm_sock_alloc(struct sock *sock, gfp_t priority)
+{
+	if (blob_sizes.lbs_sock == 0) {
+		sock->sk_security = NULL;
+		return 0;
+	}
+
+	sock->sk_security = kzalloc(blob_sizes.lbs_sock, priority);
+	if (sock->sk_security == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
 /**
  * lsm_superblock_alloc - allocate a composite superblock blob
  * @sb: the superblock that needs a blob
@@ -2048,12 +2073,21 @@ EXPORT_SYMBOL(security_socket_getpeersec_dgram);
 
 int security_sk_alloc(struct sock *sk, int family, gfp_t priority)
 {
-	return call_int_hook(sk_alloc_security, 0, sk, family, priority);
+	int rc = lsm_sock_alloc(sk, priority);
+
+	if (unlikely(rc))
+		return rc;
+	rc = call_int_hook(sk_alloc_security, 0, sk, family, priority);
+	if (unlikely(rc))
+		security_sk_free(sk);
+	return rc;
 }
 
 void security_sk_free(struct sock *sk)
 {
 	call_void_hook(sk_free_security, sk);
+	kfree(sk->sk_security);
+	sk->sk_security = NULL;
 }
 
 void security_sk_clone(const struct sock *sk, struct sock *newsk)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 7478d8eda00a..f38a6f484613 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4319,7 +4319,7 @@ static int socket_sockcreate_sid(const struct task_security_struct *tsec,
 
 static int sock_has_perm(struct sock *sk, u32 perms)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct common_audit_data ad;
 	struct lsm_network_audit net = {0,};
 
@@ -4376,7 +4376,7 @@ static int selinux_socket_post_create(struct socket *sock, int family,
 	isec->initialized = LABEL_INITIALIZED;
 
 	if (sock->sk) {
-		sksec = sock->sk->sk_security;
+		sksec = selinux_sock(sock->sk);
 		sksec->sclass = sclass;
 		sksec->sid = sid;
 		/* Allows detection of the first association on this socket */
@@ -4392,8 +4392,8 @@ static int selinux_socket_post_create(struct socket *sock, int family,
 static int selinux_socket_socketpair(struct socket *socka,
 				     struct socket *sockb)
 {
-	struct sk_security_struct *sksec_a = socka->sk->sk_security;
-	struct sk_security_struct *sksec_b = sockb->sk->sk_security;
+	struct sk_security_struct *sksec_a = selinux_sock(socka->sk);
+	struct sk_security_struct *sksec_b = selinux_sock(sockb->sk);
 
 	sksec_a->peer_sid = sksec_b->sid;
 	sksec_b->peer_sid = sksec_a->sid;
@@ -4408,7 +4408,7 @@ static int selinux_socket_socketpair(struct socket *socka,
 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
 {
 	struct sock *sk = sock->sk;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	u16 family;
 	int err;
 
@@ -4540,7 +4540,7 @@ static int selinux_socket_connect_helper(struct socket *sock,
 					 struct sockaddr *address, int addrlen)
 {
 	struct sock *sk = sock->sk;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	int err;
 
 	err = sock_has_perm(sk, SOCKET__CONNECT);
@@ -4711,9 +4711,9 @@ static int selinux_socket_unix_stream_connect(struct sock *sock,
 					      struct sock *other,
 					      struct sock *newsk)
 {
-	struct sk_security_struct *sksec_sock = sock->sk_security;
-	struct sk_security_struct *sksec_other = other->sk_security;
-	struct sk_security_struct *sksec_new = newsk->sk_security;
+	struct sk_security_struct *sksec_sock = selinux_sock(sock);
+	struct sk_security_struct *sksec_other = selinux_sock(other);
+	struct sk_security_struct *sksec_new = selinux_sock(newsk);
 	struct common_audit_data ad;
 	struct lsm_network_audit net = {0,};
 	int err;
@@ -4745,8 +4745,8 @@ static int selinux_socket_unix_stream_connect(struct sock *sock,
 static int selinux_socket_unix_may_send(struct socket *sock,
 					struct socket *other)
 {
-	struct sk_security_struct *ssec = sock->sk->sk_security;
-	struct sk_security_struct *osec = other->sk->sk_security;
+	struct sk_security_struct *ssec = selinux_sock(sock->sk);
+	struct sk_security_struct *osec = selinux_sock(other->sk);
 	struct common_audit_data ad;
 	struct lsm_network_audit net = {0,};
 
@@ -4788,7 +4788,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
 				       u16 family)
 {
 	int err = 0;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	u32 sk_sid = sksec->sid;
 	struct common_audit_data ad;
 	struct lsm_network_audit net = {0,};
@@ -4821,7 +4821,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
 	int err;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	u16 family = sk->sk_family;
 	u32 sk_sid = sksec->sid;
 	struct common_audit_data ad;
@@ -4889,13 +4889,15 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 	return err;
 }
 
-static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
-					    int __user *optlen, unsigned len)
+static int selinux_socket_getpeersec_stream(struct socket *sock,
+					    __user char *optval,
+					    __user int *optlen,
+					    unsigned int len)
 {
 	int err = 0;
 	char *scontext;
 	u32 scontext_len;
-	struct sk_security_struct *sksec = sock->sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sock->sk);
 	u32 peer_sid = SECSID_NULL;
 
 	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
@@ -4955,34 +4957,27 @@ static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *
 
 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
 {
-	struct sk_security_struct *sksec;
-
-	sksec = kzalloc(sizeof(*sksec), priority);
-	if (!sksec)
-		return -ENOMEM;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	sksec->peer_sid = SECINITSID_UNLABELED;
 	sksec->sid = SECINITSID_UNLABELED;
 	sksec->sclass = SECCLASS_SOCKET;
 	selinux_netlbl_sk_security_reset(sksec);
-	sk->sk_security = sksec;
 
 	return 0;
 }
 
 static void selinux_sk_free_security(struct sock *sk)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
-	sk->sk_security = NULL;
 	selinux_netlbl_sk_security_free(sksec);
-	kfree(sksec);
 }
 
 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
-	struct sk_security_struct *newsksec = newsk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
+	struct sk_security_struct *newsksec = selinux_sock(newsk);
 
 	newsksec->sid = sksec->sid;
 	newsksec->peer_sid = sksec->peer_sid;
@@ -4996,7 +4991,7 @@ static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
 	if (!sk)
 		*secid = SECINITSID_ANY_SOCKET;
 	else {
-		struct sk_security_struct *sksec = sk->sk_security;
+		struct sk_security_struct *sksec = selinux_sock(sk);
 
 		*secid = sksec->sid;
 	}
@@ -5006,7 +5001,7 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
 {
 	struct inode_security_struct *isec =
 		inode_security_novalidate(SOCK_INODE(parent));
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
 	    sk->sk_family == PF_UNIX)
@@ -5021,7 +5016,7 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
 static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
 				      struct sk_buff *skb)
 {
-	struct sk_security_struct *sksec = ep->base.sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(ep->base.sk);
 	struct common_audit_data ad;
 	struct lsm_network_audit net = {0,};
 	u8 peerlbl_active;
@@ -5172,8 +5167,8 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname,
 static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
 				  struct sock *newsk)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
-	struct sk_security_struct *newsksec = newsk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
+	struct sk_security_struct *newsksec = selinux_sock(newsk);
 
 	/* If policy does not support SECCLASS_SCTP_SOCKET then call
 	 * the non-sctp clone version.
@@ -5190,7 +5185,7 @@ static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 				     struct request_sock *req)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	int err;
 	u16 family = req->rsk_ops->family;
 	u32 connsid;
@@ -5211,7 +5206,7 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 static void selinux_inet_csk_clone(struct sock *newsk,
 				   const struct request_sock *req)
 {
-	struct sk_security_struct *newsksec = newsk->sk_security;
+	struct sk_security_struct *newsksec = selinux_sock(newsk);
 
 	newsksec->sid = req->secid;
 	newsksec->peer_sid = req->peer_secid;
@@ -5228,7 +5223,7 @@ static void selinux_inet_csk_clone(struct sock *newsk,
 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
 {
 	u16 family = sk->sk_family;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
@@ -5312,7 +5307,7 @@ static int selinux_tun_dev_attach_queue(void *security)
 static int selinux_tun_dev_attach(struct sock *sk, void *security)
 {
 	struct tun_security_struct *tunsec = security;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	/* we don't currently perform any NetLabel based labeling here and it
 	 * isn't clear that we would want to do so anyway; while we could apply
@@ -5353,7 +5348,7 @@ static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
 	int err = 0;
 	u32 perm;
 	struct nlmsghdr *nlh;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	if (skb->len < NLMSG_HDRLEN) {
 		err = -EINVAL;
@@ -5494,7 +5489,7 @@ static unsigned int selinux_ip_output(struct sk_buff *skb,
 			return NF_ACCEPT;
 
 		/* standard practice, label using the parent socket */
-		sksec = sk->sk_security;
+		sksec = selinux_sock(sk);
 		sid = sksec->sid;
 	} else
 		sid = SECINITSID_KERNEL;
@@ -5533,7 +5528,7 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
 
 	if (sk == NULL)
 		return NF_ACCEPT;
-	sksec = sk->sk_security;
+	sksec = selinux_sock(sk);
 
 	ad.type = LSM_AUDIT_DATA_NET;
 	ad.u.net = &net;
@@ -5625,7 +5620,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb,
 		u32 skb_sid;
 		struct sk_security_struct *sksec;
 
-		sksec = sk->sk_security;
+		sksec = selinux_sock(sk);
 		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
 			return NF_DROP;
 		/* At this point, if the returned skb peerlbl is SECSID_NULL
@@ -5654,7 +5649,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb,
 	} else {
 		/* Locally generated packet, fetch the security label from the
 		 * associated socket. */
-		struct sk_security_struct *sksec = sk->sk_security;
+		struct sk_security_struct *sksec = selinux_sock(sk);
 		peer_sid = sksec->sid;
 		secmark_perm = PACKET__SEND;
 	}
@@ -6633,6 +6628,7 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
 	.lbs_inode = sizeof(struct inode_security_struct),
 	.lbs_ipc = sizeof(struct ipc_security_struct),
 	.lbs_msg_msg = sizeof(struct msg_security_struct),
+	.lbs_sock = sizeof(struct sk_security_struct),
 	.lbs_superblock = sizeof(struct superblock_security_struct),
 };
 
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index d08d7e5d2f93..29f02b8f8f31 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -194,4 +194,9 @@ static inline struct superblock_security_struct *selinux_superblock(
 	return superblock->s_security + selinux_blob_sizes.lbs_superblock;
 }
 
+static inline struct sk_security_struct *selinux_sock(const struct sock *sock)
+{
+	return sock->sk_security + selinux_blob_sizes.lbs_sock;
+}
+
 #endif /* _SELINUX_OBJSEC_H_ */
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index 186e727b737b..c40914a157b7 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -31,6 +31,7 @@
 #include <linux/gfp.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
+#include <linux/lsm_hooks.h>
 #include <net/sock.h>
 #include <net/netlabel.h>
 #include <net/ip.h>
@@ -81,7 +82,7 @@ static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
 static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
 {
 	int rc;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct netlbl_lsm_secattr *secattr;
 
 	if (sksec->nlbl_secattr != NULL)
@@ -114,7 +115,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
 							const struct sock *sk,
 							u32 sid)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr;
 
 	if (secattr == NULL)
@@ -249,7 +250,7 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
 	 * being labeled by it's parent socket, if it is just exit */
 	sk = skb_to_full_sk(skb);
 	if (sk != NULL) {
-		struct sk_security_struct *sksec = sk->sk_security;
+		struct sk_security_struct *sksec = selinux_sock(sk);
 
 		if (sksec->nlbl_state != NLBL_REQSKB)
 			return 0;
@@ -287,7 +288,7 @@ int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
 {
 	int rc;
 	struct netlbl_lsm_secattr secattr;
-	struct sk_security_struct *sksec = ep->base.sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(ep->base.sk);
 	struct sockaddr *addr;
 	struct sockaddr_in addr4;
 #if IS_ENABLED(CONFIG_IPV6)
@@ -370,7 +371,7 @@ int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
  */
 void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	if (family == PF_INET)
 		sksec->nlbl_state = NLBL_LABELED;
@@ -388,8 +389,8 @@ void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
  */
 void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
-	struct sk_security_struct *newsksec = newsk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
+	struct sk_security_struct *newsksec = selinux_sock(newsk);
 
 	newsksec->nlbl_state = sksec->nlbl_state;
 }
@@ -407,7 +408,7 @@ void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
 int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
 {
 	int rc;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct netlbl_lsm_secattr *secattr;
 
 	if (family != PF_INET && family != PF_INET6)
@@ -522,7 +523,7 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
 {
 	int rc = 0;
 	struct sock *sk = sock->sk;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct netlbl_lsm_secattr secattr;
 
 	if (selinux_netlbl_option(level, optname) &&
@@ -560,7 +561,7 @@ static int selinux_netlbl_socket_connect_helper(struct sock *sk,
 						struct sockaddr *addr)
 {
 	int rc;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct netlbl_lsm_secattr *secattr;
 
 	/* connected sockets are allowed to disconnect when the address family
@@ -599,7 +600,7 @@ static int selinux_netlbl_socket_connect_helper(struct sock *sk,
 int selinux_netlbl_socket_connect_locked(struct sock *sk,
 					 struct sockaddr *addr)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	if (sksec->nlbl_state != NLBL_REQSKB &&
 	    sksec->nlbl_state != NLBL_CONNLABELED)
diff --git a/security/smack/smack.h b/security/smack/smack.h
index caecbcba9942..4ac4bf3310d7 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -375,6 +375,11 @@ static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc)
 	return ipc->security + smack_blob_sizes.lbs_ipc;
 }
 
+static inline struct socket_smack *smack_sock(const struct sock *sock)
+{
+	return sock->sk_security + smack_blob_sizes.lbs_sock;
+}
+
 static inline struct superblock_smack *smack_superblock(
 					const struct super_block *superblock)
 {
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 807eff2ccce9..fd69e1bd841b 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1439,7 +1439,7 @@ static int smack_inode_getsecurity(struct inode *inode,
 		if (sock == NULL || sock->sk == NULL)
 			return -EOPNOTSUPP;
 
-		ssp = sock->sk->sk_security;
+		ssp = smack_sock(sock->sk);
 
 		if (strcmp(name, XATTR_SMACK_IPIN) == 0)
 			isp = ssp->smk_in;
@@ -1821,7 +1821,7 @@ static int smack_file_receive(struct file *file)
 
 	if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
 		sock = SOCKET_I(inode);
-		ssp = sock->sk->sk_security;
+		ssp = smack_sock(sock->sk);
 		tsp = smack_cred(current_cred());
 		/*
 		 * If the receiving process can't write to the
@@ -2231,11 +2231,7 @@ static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
 {
 	struct smack_known *skp = smk_of_current();
-	struct socket_smack *ssp;
-
-	ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
-	if (ssp == NULL)
-		return -ENOMEM;
+	struct socket_smack *ssp = smack_sock(sk);
 
 	/*
 	 * Sockets created by kernel threads receive web label.
@@ -2249,11 +2245,10 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
 	}
 	ssp->smk_packet = NULL;
 
-	sk->sk_security = ssp;
-
 	return 0;
 }
 
+#ifdef SMACK_IPV6_PORT_LABELING
 /**
  * smack_sk_free_security - Free a socket blob
  * @sk: the socket
@@ -2262,7 +2257,6 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
  */
 static void smack_sk_free_security(struct sock *sk)
 {
-#ifdef SMACK_IPV6_PORT_LABELING
 	struct smk_port_label *spp;
 
 	if (sk->sk_family == PF_INET6) {
@@ -2275,9 +2269,8 @@ static void smack_sk_free_security(struct sock *sk)
 		}
 		rcu_read_unlock();
 	}
-#endif
-	kfree(sk->sk_security);
 }
+#endif
 
 /**
 * smack_ipv4host_label - check host based restrictions
@@ -2395,7 +2388,7 @@ static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
 static int smack_netlabel(struct sock *sk, int labeled)
 {
 	struct smack_known *skp;
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 	int rc = 0;
 
 	/*
@@ -2440,7 +2433,7 @@ static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
 	int rc;
 	int sk_lbl;
 	struct smack_known *hkp;
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 	struct smk_audit_info ad;
 
 	rcu_read_lock();
@@ -2516,7 +2509,7 @@ static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
 {
 	struct sock *sk = sock->sk;
 	struct sockaddr_in6 *addr6;
-	struct socket_smack *ssp = sock->sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sock->sk);
 	struct smk_port_label *spp;
 	unsigned short port = 0;
 
@@ -2603,7 +2596,7 @@ static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
 				int act)
 {
 	struct smk_port_label *spp;
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 	struct smack_known *skp = NULL;
 	unsigned short port;
 	struct smack_known *object;
@@ -2697,7 +2690,7 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
 	if (sock == NULL || sock->sk == NULL)
 		return -EOPNOTSUPP;
 
-	ssp = sock->sk->sk_security;
+	ssp = smack_sock(sock->sk);
 
 	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
 		ssp->smk_in = skp;
@@ -2745,7 +2738,7 @@ static int smack_socket_post_create(struct socket *sock, int family,
 	 * Sockets created by kernel threads receive web label.
 	 */
 	if (unlikely(current->flags & PF_KTHREAD)) {
-		ssp = sock->sk->sk_security;
+		ssp = smack_sock(sock->sk);
 		ssp->smk_in = &smack_known_web;
 		ssp->smk_out = &smack_known_web;
 	}
@@ -2770,8 +2763,8 @@ static int smack_socket_post_create(struct socket *sock, int family,
 static int smack_socket_socketpair(struct socket *socka,
 		                   struct socket *sockb)
 {
-	struct socket_smack *asp = socka->sk->sk_security;
-	struct socket_smack *bsp = sockb->sk->sk_security;
+	struct socket_smack *asp = smack_sock(socka->sk);
+	struct socket_smack *bsp = smack_sock(sockb->sk);
 
 	asp->smk_packet = bsp->smk_out;
 	bsp->smk_packet = asp->smk_out;
@@ -2825,7 +2818,7 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
 		return 0;
 
 #ifdef SMACK_IPV6_SECMARK_LABELING
-	ssp = sock->sk->sk_security;
+	ssp = smack_sock(sock->sk);
 #endif
 
 	switch (sock->sk->sk_family) {
@@ -3566,9 +3559,9 @@ static int smack_unix_stream_connect(struct sock *sock,
 {
 	struct smack_known *skp;
 	struct smack_known *okp;
-	struct socket_smack *ssp = sock->sk_security;
-	struct socket_smack *osp = other->sk_security;
-	struct socket_smack *nsp = newsk->sk_security;
+	struct socket_smack *ssp = smack_sock(sock);
+	struct socket_smack *osp = smack_sock(other);
+	struct socket_smack *nsp = smack_sock(newsk);
 	struct smk_audit_info ad;
 	int rc = 0;
 #ifdef CONFIG_AUDIT
@@ -3614,8 +3607,8 @@ static int smack_unix_stream_connect(struct sock *sock,
  */
 static int smack_unix_may_send(struct socket *sock, struct socket *other)
 {
-	struct socket_smack *ssp = sock->sk->sk_security;
-	struct socket_smack *osp = other->sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sock->sk);
+	struct socket_smack *osp = smack_sock(other->sk);
 	struct smk_audit_info ad;
 	int rc;
 
@@ -3652,7 +3645,7 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
 	struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
 #endif
 #ifdef SMACK_IPV6_SECMARK_LABELING
-	struct socket_smack *ssp = sock->sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sock->sk);
 	struct smack_known *rsp;
 #endif
 	int rc = 0;
@@ -3817,7 +3810,7 @@ static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
 	struct netlbl_lsm_secattr secattr;
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 	struct smack_known *skp = NULL;
 	int rc = 0;
 	struct smk_audit_info ad;
@@ -3934,7 +3927,7 @@ static int smack_socket_getpeersec_stream(struct socket *sock,
 	int slen = 1;
 	int rc = 0;
 
-	ssp = sock->sk->sk_security;
+	ssp = smack_sock(sock->sk);
 	if (ssp->smk_packet != NULL) {
 		rcp = ssp->smk_packet->smk_known;
 		slen = strlen(rcp) + 1;
@@ -3984,7 +3977,7 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
 
 	switch (family) {
 	case PF_UNIX:
-		ssp = sock->sk->sk_security;
+		ssp = smack_sock(sock->sk);
 		s = ssp->smk_out->smk_secid;
 		break;
 	case PF_INET:
@@ -3997,7 +3990,7 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
 		 * Translate what netlabel gave us.
 		 */
 		if (sock != NULL && sock->sk != NULL)
-			ssp = sock->sk->sk_security;
+			ssp = smack_sock(sock->sk);
 		netlbl_secattr_init(&secattr);
 		rc = netlbl_skbuff_getattr(skb, family, &secattr);
 		if (rc == 0) {
@@ -4035,7 +4028,7 @@ static void smack_sock_graft(struct sock *sk, struct socket *parent)
 	    (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
 		return;
 
-	ssp = sk->sk_security;
+	ssp = smack_sock(sk);
 	ssp->smk_in = skp;
 	ssp->smk_out = skp;
 	/* cssp->smk_packet is already set in smack_inet_csk_clone() */
@@ -4055,7 +4048,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 {
 	u16 family = sk->sk_family;
 	struct smack_known *skp;
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 	struct netlbl_lsm_secattr secattr;
 	struct sockaddr_in addr;
 	struct iphdr *hdr;
@@ -4154,7 +4147,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 static void smack_inet_csk_clone(struct sock *sk,
 				 const struct request_sock *req)
 {
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 	struct smack_known *skp;
 
 	if (req->peer_secid != 0) {
@@ -4558,6 +4551,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
 	.lbs_inode = sizeof(struct inode_smack),
 	.lbs_ipc = sizeof(struct smack_known *),
 	.lbs_msg_msg = sizeof(struct smack_known *),
+	.lbs_sock = sizeof(struct socket_smack),
 	.lbs_superblock = sizeof(struct superblock_smack),
 };
 
@@ -4667,7 +4661,9 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream),
 	LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram),
 	LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security),
+#ifdef SMACK_IPV6_PORT_LABELING
 	LSM_HOOK_INIT(sk_free_security, smack_sk_free_security),
+#endif
 	LSM_HOOK_INIT(sock_graft, smack_sock_graft),
 	LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request),
 	LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone),
diff --git a/security/smack/smack_netfilter.c b/security/smack/smack_netfilter.c
index e36d17835d4f..701a1cc1bdcc 100644
--- a/security/smack/smack_netfilter.c
+++ b/security/smack/smack_netfilter.c
@@ -31,8 +31,8 @@ static unsigned int smack_ipv6_output(void *priv,
 	struct socket_smack *ssp;
 	struct smack_known *skp;
 
-	if (sk && sk->sk_security) {
-		ssp = sk->sk_security;
+	if (sk && smack_sock(sk)) {
+		ssp = smack_sock(sk);
 		skp = ssp->smk_out;
 		skb->secmark = skp->smk_secid;
 	}
@@ -49,8 +49,8 @@ static unsigned int smack_ipv4_output(void *priv,
 	struct socket_smack *ssp;
 	struct smack_known *skp;
 
-	if (sk && sk->sk_security) {
-		ssp = sk->sk_security;
+	if (sk && smack_sock(sk)) {
+		ssp = smack_sock(sk);
 		skp = ssp->smk_out;
 		skb->secmark = skp->smk_secid;
 	}
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 03/24] LSM: Infrastructure management of the key blob
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
  2019-06-21 18:52 ` [PATCH v3 01/24] LSM: Infrastructure management of the superblock Casey Schaufler
  2019-06-21 18:52 ` [PATCH v3 02/24] LSM: Infrastructure management of the sock security Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-24 18:33   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 04/24] LSM: Create and manage the lsmblob data structure Casey Schaufler
                   ` (20 subsequent siblings)
  23 siblings, 1 reply; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

From: Casey Schaufler <cschaufler@schaufler-ca.com>

Move management of the key->security blob out of the
individual security modules and into the security
infrastructure. Instead of allocating the blobs from within
the modules the modules tell the infrastructure how much
space is required, and the space is allocated there.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h         |  1 +
 security/security.c               | 40 ++++++++++++++++++++++++++++++-
 security/selinux/hooks.c          | 23 +++++-------------
 security/selinux/include/objsec.h |  7 ++++++
 security/smack/smack.h            |  7 ++++++
 security/smack/smack_lsm.c        | 33 ++++++++++++-------------
 6 files changed, 75 insertions(+), 36 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index b353482ea348..3fe39abccc8f 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2050,6 +2050,7 @@ struct lsm_blob_sizes {
 	int	lbs_sock;
 	int	lbs_superblock;
 	int	lbs_ipc;
+	int	lbs_key;
 	int	lbs_msg_msg;
 	int	lbs_task;
 };
diff --git a/security/security.c b/security/security.c
index e32b7180282e..d05f00a40e82 100644
--- a/security/security.c
+++ b/security/security.c
@@ -172,6 +172,9 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed)
 		blob_sizes.lbs_inode = sizeof(struct rcu_head);
 	lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode);
 	lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc);
+#ifdef CONFIG_KEYS
+	lsm_set_blob_size(&needed->lbs_key, &blob_sizes.lbs_key);
+#endif
 	lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg);
 	lsm_set_blob_size(&needed->lbs_sock, &blob_sizes.lbs_sock);
 	lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock);
@@ -307,6 +310,9 @@ static void __init ordered_lsm_init(void)
 	init_debug("file blob size       = %d\n", blob_sizes.lbs_file);
 	init_debug("inode blob size      = %d\n", blob_sizes.lbs_inode);
 	init_debug("ipc blob size        = %d\n", blob_sizes.lbs_ipc);
+#ifdef CONFIG_KEYS
+	init_debug("key blob size        = %d\n", blob_sizes.lbs_key);
+#endif /* CONFIG_KEYS */
 	init_debug("msg_msg blob size    = %d\n", blob_sizes.lbs_msg_msg);
 	init_debug("sock blob size       = %d\n", blob_sizes.lbs_sock);
 	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
@@ -573,6 +579,29 @@ static int lsm_ipc_alloc(struct kern_ipc_perm *kip)
 	return 0;
 }
 
+#ifdef CONFIG_KEYS
+/**
+ * lsm_key_alloc - allocate a composite key blob
+ * @key: the key that needs a blob
+ *
+ * Allocate the key blob for all the modules
+ *
+ * Returns 0, or -ENOMEM if memory can't be allocated.
+ */
+int lsm_key_alloc(struct key *key)
+{
+	if (blob_sizes.lbs_key == 0) {
+		key->security = NULL;
+		return 0;
+	}
+
+	key->security = kzalloc(blob_sizes.lbs_key, GFP_KERNEL);
+	if (key->security == NULL)
+		return -ENOMEM;
+	return 0;
+}
+#endif /* CONFIG_KEYS */
+
 /**
  * lsm_msg_msg_alloc - allocate a composite msg_msg blob
  * @mp: the msg_msg that needs a blob
@@ -2339,12 +2368,21 @@ EXPORT_SYMBOL(security_skb_classify_flow);
 int security_key_alloc(struct key *key, const struct cred *cred,
 		       unsigned long flags)
 {
-	return call_int_hook(key_alloc, 0, key, cred, flags);
+	int rc = lsm_key_alloc(key);
+
+	if (unlikely(rc))
+		return rc;
+	rc = call_int_hook(key_alloc, 0, key, cred, flags);
+	if (unlikely(rc))
+		security_key_free(key);
+	return rc;
 }
 
 void security_key_free(struct key *key)
 {
 	call_void_hook(key_free, key);
+	kfree(key->security);
+	key->security = NULL;
 }
 
 int security_key_permission(key_ref_t key_ref,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index f38a6f484613..ee840fecfebb 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6353,11 +6353,7 @@ static int selinux_key_alloc(struct key *k, const struct cred *cred,
 			     unsigned long flags)
 {
 	const struct task_security_struct *tsec;
-	struct key_security_struct *ksec;
-
-	ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
-	if (!ksec)
-		return -ENOMEM;
+	struct key_security_struct *ksec = selinux_key(k);
 
 	tsec = selinux_cred(cred);
 	if (tsec->keycreate_sid)
@@ -6365,18 +6361,9 @@ static int selinux_key_alloc(struct key *k, const struct cred *cred,
 	else
 		ksec->sid = tsec->sid;
 
-	k->security = ksec;
 	return 0;
 }
 
-static void selinux_key_free(struct key *k)
-{
-	struct key_security_struct *ksec = k->security;
-
-	k->security = NULL;
-	kfree(ksec);
-}
-
 static int selinux_key_permission(key_ref_t key_ref,
 				  const struct cred *cred,
 				  unsigned perm)
@@ -6394,7 +6381,7 @@ static int selinux_key_permission(key_ref_t key_ref,
 	sid = cred_sid(cred);
 
 	key = key_ref_to_ptr(key_ref);
-	ksec = key->security;
+	ksec = selinux_key(key);
 
 	return avc_has_perm(&selinux_state,
 			    sid, ksec->sid, SECCLASS_KEY, perm, NULL);
@@ -6402,7 +6389,7 @@ static int selinux_key_permission(key_ref_t key_ref,
 
 static int selinux_key_getsecurity(struct key *key, char **_buffer)
 {
-	struct key_security_struct *ksec = key->security;
+	struct key_security_struct *ksec = selinux_key(key);
 	char *context = NULL;
 	unsigned len;
 	int rc;
@@ -6627,6 +6614,9 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
 	.lbs_file = sizeof(struct file_security_struct),
 	.lbs_inode = sizeof(struct inode_security_struct),
 	.lbs_ipc = sizeof(struct ipc_security_struct),
+#ifdef CONFIG_KEYS
+	.lbs_key = sizeof(struct key_security_struct),
+#endif /* CONFIG_KEYS */
 	.lbs_msg_msg = sizeof(struct msg_security_struct),
 	.lbs_sock = sizeof(struct sk_security_struct),
 	.lbs_superblock = sizeof(struct superblock_security_struct),
@@ -6842,7 +6832,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
 
 #ifdef CONFIG_KEYS
 	LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
-	LSM_HOOK_INIT(key_free, selinux_key_free),
 	LSM_HOOK_INIT(key_permission, selinux_key_permission),
 	LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
 #endif
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index 29f02b8f8f31..3b78aa4ee98f 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -194,6 +194,13 @@ static inline struct superblock_security_struct *selinux_superblock(
 	return superblock->s_security + selinux_blob_sizes.lbs_superblock;
 }
 
+#ifdef CONFIG_KEYS
+static inline struct key_security_struct *selinux_key(const struct key *key)
+{
+	return key->security + selinux_blob_sizes.lbs_key;
+}
+#endif /* CONFIG_KEYS */
+
 static inline struct sk_security_struct *selinux_sock(const struct sock *sock)
 {
 	return sock->sk_security + selinux_blob_sizes.lbs_sock;
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 4ac4bf3310d7..7cc3a3382fee 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -386,6 +386,13 @@ static inline struct superblock_smack *smack_superblock(
 	return superblock->s_security + smack_blob_sizes.lbs_superblock;
 }
 
+#ifdef CONFIG_KEYS
+static inline struct smack_known **smack_key(const struct key *key)
+{
+	return key->security + smack_blob_sizes.lbs_key;
+}
+#endif /* CONFIG_KEYS */
+
 /*
  * Is the directory transmuting?
  */
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index fd69e1bd841b..e9560b078efe 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4179,23 +4179,13 @@ static void smack_inet_csk_clone(struct sock *sk,
 static int smack_key_alloc(struct key *key, const struct cred *cred,
 			   unsigned long flags)
 {
+	struct smack_known **blob = smack_key(key);
 	struct smack_known *skp = smk_of_task(smack_cred(cred));
 
-	key->security = skp;
+	*blob = skp;
 	return 0;
 }
 
-/**
- * smack_key_free - Clear the key security blob
- * @key: the object
- *
- * Clear the blob pointer
- */
-static void smack_key_free(struct key *key)
-{
-	key->security = NULL;
-}
-
 /**
  * smack_key_permission - Smack access on a key
  * @key_ref: gets to the object
@@ -4208,6 +4198,8 @@ static void smack_key_free(struct key *key)
 static int smack_key_permission(key_ref_t key_ref,
 				const struct cred *cred, unsigned perm)
 {
+	struct smack_known **blob;
+	struct smack_known *skp;
 	struct key *keyp;
 	struct smk_audit_info ad;
 	struct smack_known *tkp = smk_of_task(smack_cred(cred));
@@ -4227,7 +4219,9 @@ static int smack_key_permission(key_ref_t key_ref,
 	 * If the key hasn't been initialized give it access so that
 	 * it may do so.
 	 */
-	if (keyp->security == NULL)
+	blob = smack_key(keyp);
+	skp = *blob;
+	if (skp == NULL)
 		return 0;
 	/*
 	 * This should not occur
@@ -4247,8 +4241,8 @@ static int smack_key_permission(key_ref_t key_ref,
 		request |= MAY_READ;
 	if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR))
 		request |= MAY_WRITE;
-	rc = smk_access(tkp, keyp->security, request, &ad);
-	rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
+	rc = smk_access(tkp, skp, request, &ad);
+	rc = smk_bu_note("key access", tkp, skp, request, rc);
 	return rc;
 }
 
@@ -4263,11 +4257,12 @@ static int smack_key_permission(key_ref_t key_ref,
  */
 static int smack_key_getsecurity(struct key *key, char **_buffer)
 {
-	struct smack_known *skp = key->security;
+	struct smack_known **blob = smack_key(key);
+	struct smack_known *skp = *blob;
 	size_t length;
 	char *copy;
 
-	if (key->security == NULL) {
+	if (skp == NULL) {
 		*_buffer = NULL;
 		return 0;
 	}
@@ -4550,6 +4545,9 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
 	.lbs_file = sizeof(struct smack_known *),
 	.lbs_inode = sizeof(struct inode_smack),
 	.lbs_ipc = sizeof(struct smack_known *),
+#ifdef CONFIG_KEYS
+	.lbs_key = sizeof(struct smack_known *),
+#endif /* CONFIG_KEYS */
 	.lbs_msg_msg = sizeof(struct smack_known *),
 	.lbs_sock = sizeof(struct socket_smack),
 	.lbs_superblock = sizeof(struct superblock_smack),
@@ -4671,7 +4669,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
  /* key management security hooks */
 #ifdef CONFIG_KEYS
 	LSM_HOOK_INIT(key_alloc, smack_key_alloc),
-	LSM_HOOK_INIT(key_free, smack_key_free),
 	LSM_HOOK_INIT(key_permission, smack_key_permission),
 	LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity),
 #endif /* CONFIG_KEYS */
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 04/24] LSM: Create and manage the lsmblob data structure.
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (2 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 03/24] LSM: Infrastructure management of the key blob Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:42   ` Kees Cook
  2019-06-24 18:38   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 05/24] Use lsmblob in security_audit_rule_match Casey Schaufler
                   ` (19 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

When more than one security module is exporting data to
audit and networking sub-systems a single 32 bit integer
is no longer sufficient to represent the data. Add a
structure to be used instead.

The lsmblob structure is currently an array of
u32 "secids". There is an entry for each of the
security modules built into the system that would
use secids if active. The system assigns the module
a "slot" when it registers hooks. If modules are
compiled in but not registered there will be unused
slots.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h |  1 +
 include/linux/security.h  | 62 +++++++++++++++++++++++++++++++++++++++
 security/security.c       | 36 +++++++++++++++++++++++
 3 files changed, 99 insertions(+)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 3fe39abccc8f..4d1ddf1a2aa6 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2038,6 +2038,7 @@ struct security_hook_list {
 	struct hlist_head		*head;
 	union security_list_options	hook;
 	char				*lsm;
+	int				slot;
 } __randomize_layout;
 
 /*
diff --git a/include/linux/security.h b/include/linux/security.h
index 49f2685324b0..0aa9417a5762 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -76,6 +76,68 @@ enum lsm_event {
 	LSM_POLICY_CHANGE,
 };
 
+/*
+ * Data exported by the security modules
+ */
+#define LSMBLOB_ENTRIES ( \
+	(IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \
+	(IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \
+	(IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0))
+
+struct lsmblob {
+	u32     secid[LSMBLOB_ENTRIES];
+};
+
+#define LSMBLOB_INVALID	-1
+
+/**
+ * lsmblob_init - initialize an lsmblob structure.
+ * @blob: Pointer to the data to initialize
+ * @secid: The initial secid value
+ *
+ * Set all secid for all modules to the specified value.
+ */
+static inline void lsmblob_init(struct lsmblob *blob, u32 secid)
+{
+	int i;
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++)
+		blob->secid[i] = secid;
+}
+
+/**
+ * lsmblob_is_set - report if there is an value in the lsmblob
+ * @blob: Pointer to the exported LSM data
+ *
+ * Returns true if there is a secid set, false otherwise
+ */
+static inline bool lsmblob_is_set(struct lsmblob *blob)
+{
+	int i;
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++)
+		if (blob->secid[i] != 0)
+			return true;
+	return false;
+}
+
+/**
+ * lsmblob_equal - report if the two lsmblob's are equal
+ * @bloba: Pointer to one LSM data
+ * @blobb: Pointer to the other LSM data
+ *
+ * Returns true if all entries in the two are equal, false otherwise
+ */
+static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)
+{
+	int i;
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++)
+		if (bloba->secid[i] != blobb->secid[i])
+			return false;
+	return true;
+}
+
 /* These functions are in security/commoncap.c */
 extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
 		       int cap, unsigned int opts);
diff --git a/security/security.c b/security/security.c
index d05f00a40e82..7618c761060d 100644
--- a/security/security.c
+++ b/security/security.c
@@ -317,6 +317,7 @@ static void __init ordered_lsm_init(void)
 	init_debug("sock blob size       = %d\n", blob_sizes.lbs_sock);
 	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
 	init_debug("task blob size       = %d\n", blob_sizes.lbs_task);
+	init_debug("lsmblob size         = %lu\n", sizeof(struct lsmblob));
 
 	/*
 	 * Create any kmem_caches needed for blobs
@@ -420,6 +421,11 @@ static int lsm_append(char *new, char **result)
 	return 0;
 }
 
+/*
+ * Current index to use while initializing the lsmblob secid list.
+ */
+static int lsm_slot __initdata;
+
 /**
  * security_add_hooks - Add a modules hooks to the hook lists.
  * @hooks: the hooks to add
@@ -427,15 +433,45 @@ static int lsm_append(char *new, char **result)
  * @lsm: the name of the security module
  *
  * Each LSM has to register its hooks with the infrastructure.
+ * If the LSM is using hooks that export secids allocate a slot
+ * for it in the lsmblob.
  */
 void __init security_add_hooks(struct security_hook_list *hooks, int count,
 				char *lsm)
 {
+	int slot = LSMBLOB_INVALID;
 	int i;
 
 	for (i = 0; i < count; i++) {
 		hooks[i].lsm = lsm;
 		hlist_add_tail_rcu(&hooks[i].list, hooks[i].head);
+		/*
+		 * If this is one of the hooks that uses a secid
+		 * note it so that a slot can in allocated for the
+		 * secid in the lsmblob structure.
+		 */
+		if (hooks[i].head == &security_hook_heads.audit_rule_match ||
+		    hooks[i].head == &security_hook_heads.kernel_act_as ||
+		    hooks[i].head ==
+			&security_hook_heads.socket_getpeersec_dgram ||
+		    hooks[i].head == &security_hook_heads.getprocattr ||
+		    hooks[i].head == &security_hook_heads.setprocattr ||
+		    hooks[i].head == &security_hook_heads.secctx_to_secid ||
+		    hooks[i].head == &security_hook_heads.secid_to_secctx ||
+		    hooks[i].head == &security_hook_heads.ipc_getsecid ||
+		    hooks[i].head == &security_hook_heads.task_getsecid ||
+		    hooks[i].head == &security_hook_heads.inode_getsecid ||
+		    hooks[i].head == &security_hook_heads.cred_getsecid) {
+			if (slot == LSMBLOB_INVALID) {
+				slot = lsm_slot++;
+				if (slot >= LSMBLOB_ENTRIES)
+					panic("%s Too many LSMs registered.\n",
+					      __func__);
+				init_debug("%s assigned lsmblob slot %d\n",
+					hooks[i].lsm, slot);
+			}
+		}
+		hooks[i].slot = slot;
 	}
 	if (lsm_append(lsm, &lsm_names) < 0)
 		panic("%s - Cannot get early memory.\n", __func__);
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 05/24] Use lsmblob in security_audit_rule_match
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (3 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 04/24] LSM: Create and manage the lsmblob data structure Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:43   ` Kees Cook
  2019-06-24 18:39   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 06/24] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
                   ` (18 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Change the secid parameter of security_audit_rule_match
to a lsmblob structure pointer. Pass the entry from the
lsmblob structure for the approprite slot to the LSM hook.

Change the users of security_audit_rule_match to use the
lsmblob instead of a u32. In some cases this requires a
temporary conversion using lsmblob_init() that will go
away when other interfaces get converted.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h            |  7 ++++---
 kernel/auditfilter.c                |  4 +++-
 kernel/auditsc.c                    | 14 ++++++++++----
 security/integrity/ima/ima.h        |  4 ++--
 security/integrity/ima/ima_policy.c |  7 +++++--
 security/security.c                 | 14 ++++++++++++--
 6 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 0aa9417a5762..52d89c4a9594 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1757,7 +1757,8 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer)
 #ifdef CONFIG_SECURITY
 int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule);
 int security_audit_rule_known(struct audit_krule *krule);
-int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule);
+int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
+			      void *lsmrule);
 void security_audit_rule_free(void *lsmrule);
 
 #else
@@ -1773,8 +1774,8 @@ static inline int security_audit_rule_known(struct audit_krule *krule)
 	return 0;
 }
 
-static inline int security_audit_rule_match(u32 secid, u32 field, u32 op,
-					    void *lsmrule)
+static inline int security_audit_rule_match(struct lsmblob *blob, u32 field,
+					    u32 op, void *lsmrule)
 {
 	return 0;
 }
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 63f8b3f26fab..da211065160f 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1324,6 +1324,7 @@ int audit_filter(int msgtype, unsigned int listtype)
 			struct audit_field *f = &e->rule.fields[i];
 			pid_t pid;
 			u32 sid;
+			struct lsmblob blob;
 
 			switch (f->type) {
 			case AUDIT_PID:
@@ -1354,7 +1355,8 @@ int audit_filter(int msgtype, unsigned int listtype)
 			case AUDIT_SUBJ_CLR:
 				if (f->lsm_rule) {
 					security_task_getsecid(current, &sid);
-					result = security_audit_rule_match(sid,
+					lsmblob_init(&blob, sid);
+					result = security_audit_rule_match(&blob,
 						   f->type, f->op, f->lsm_rule);
 				}
 				break;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index d1eab1d4a930..18ee5556c086 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -445,6 +445,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 	const struct cred *cred;
 	int i, need_sid = 1;
 	u32 sid;
+	struct lsmblob blob;
 	unsigned int sessionid;
 
 	cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
@@ -630,7 +631,9 @@ static int audit_filter_rules(struct task_struct *tsk,
 					security_task_getsecid(tsk, &sid);
 					need_sid = 0;
 				}
-				result = security_audit_rule_match(sid, f->type,
+				lsmblob_init(&blob, sid);
+				result = security_audit_rule_match(&blob,
+								   f->type,
 								   f->op,
 								   f->lsm_rule);
 			}
@@ -645,15 +648,17 @@ static int audit_filter_rules(struct task_struct *tsk,
 			if (f->lsm_rule) {
 				/* Find files that match */
 				if (name) {
+					lsmblob_init(&blob, name->osid);
 					result = security_audit_rule_match(
-								name->osid,
+								&blob,
 								f->type,
 								f->op,
 								f->lsm_rule);
 				} else if (ctx) {
 					list_for_each_entry(n, &ctx->names_list, list) {
+						lsmblob_init(&blob, n->osid);
 						if (security_audit_rule_match(
-								n->osid,
+								&blob,
 								f->type,
 								f->op,
 								f->lsm_rule)) {
@@ -665,7 +670,8 @@ static int audit_filter_rules(struct task_struct *tsk,
 				/* Find ipc objects that match */
 				if (!ctx || ctx->type != AUDIT_IPC)
 					break;
-				if (security_audit_rule_match(ctx->ipc.osid,
+				lsmblob_init(&blob, ctx->ipc.osid);
+				if (security_audit_rule_match(&blob,
 							      f->type, f->op,
 							      f->lsm_rule))
 					++result;
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index d213e835c498..5a337239d9e4 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -307,8 +307,8 @@ static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
 	return -EINVAL;
 }
 
-static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
-					     void *lsmrule)
+static inline int security_filter_rule_match(struct lsmblob *blob, u32 field,
+					     u32 op, void *lsmrule)
 {
 	return -EINVAL;
 }
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index e0cc323f948f..e7b8ce942950 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -327,6 +327,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 	for (i = 0; i < MAX_LSM_RULES; i++) {
 		int rc = 0;
 		u32 osid;
+		struct lsmblob blob;
 		int retried = 0;
 
 		if (!rule->lsm[i].rule)
@@ -337,7 +338,8 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 		case LSM_OBJ_ROLE:
 		case LSM_OBJ_TYPE:
 			security_inode_getsecid(inode, &osid);
-			rc = security_filter_rule_match(osid,
+			lsmblob_init(&blob, osid);
+			rc = security_filter_rule_match(&blob,
 							rule->lsm[i].type,
 							Audit_equal,
 							rule->lsm[i].rule);
@@ -345,7 +347,8 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 		case LSM_SUBJ_USER:
 		case LSM_SUBJ_ROLE:
 		case LSM_SUBJ_TYPE:
-			rc = security_filter_rule_match(secid,
+			lsmblob_init(&blob, secid);
+			rc = security_filter_rule_match(&blob,
 							rule->lsm[i].type,
 							Audit_equal,
 							rule->lsm[i].rule);
diff --git a/security/security.c b/security/security.c
index 7618c761060d..4692f44718c6 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2452,9 +2452,19 @@ void security_audit_rule_free(void *lsmrule)
 	call_void_hook(audit_rule_free, lsmrule);
 }
 
-int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
+int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
+			      void *lsmrule)
 {
-	return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule);
+	struct security_hook_list *hp;
+	int rc;
+
+	hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) {
+		rc = hp->hook.audit_rule_match(blob->secid[hp->slot], field,
+					       op, lsmrule);
+		if (rc != 0)
+			return rc;
+	}
+	return 0;
 }
 #endif /* CONFIG_AUDIT */
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 06/24] LSM: Use lsmblob in security_kernel_act_as
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (4 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 05/24] Use lsmblob in security_audit_rule_match Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:43   ` Kees Cook
  2019-06-24 18:38   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 07/24] net: Prepare UDS for secuirty module stacking Casey Schaufler
                   ` (17 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Change the security_kernel_act_as interface to use a lsmblob
structure in place of the single u32 secid in support of
module stacking. Change it's only caller, set_security_override,
to do the same. Change that one's only caller,
set_security_override_from_ctx, to call it with the new
parameter type.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/cred.h     |  3 ++-
 include/linux/security.h |  5 +++--
 kernel/cred.c            | 10 ++++++----
 security/security.c      | 12 ++++++++++--
 4 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/include/linux/cred.h b/include/linux/cred.h
index efb6edf32de7..9a21c376ed97 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -22,6 +22,7 @@
 
 struct cred;
 struct inode;
+struct lsmblob;
 
 /*
  * COW Supplementary groups list
@@ -165,7 +166,7 @@ extern const struct cred *override_creds(const struct cred *);
 extern void revert_creds(const struct cred *);
 extern struct cred *prepare_kernel_cred(struct task_struct *);
 extern int change_create_files_as(struct cred *, struct inode *);
-extern int set_security_override(struct cred *, u32);
+extern int set_security_override(struct cred *, struct lsmblob *);
 extern int set_security_override_from_ctx(struct cred *, const char *);
 extern int set_create_files_as(struct cred *, struct inode *);
 extern int cred_fscmp(const struct cred *, const struct cred *);
diff --git a/include/linux/security.h b/include/linux/security.h
index 52d89c4a9594..4a78516cc74a 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -384,7 +384,7 @@ void security_cred_free(struct cred *cred);
 int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
 void security_transfer_creds(struct cred *new, const struct cred *old);
 void security_cred_getsecid(const struct cred *c, u32 *secid);
-int security_kernel_act_as(struct cred *new, u32 secid);
+int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
 int security_kernel_create_files_as(struct cred *new, struct inode *inode);
 int security_kernel_module_request(char *kmod_name);
 int security_kernel_load_data(enum kernel_load_data_id id);
@@ -967,7 +967,8 @@ static inline void security_transfer_creds(struct cred *new,
 {
 }
 
-static inline int security_kernel_act_as(struct cred *cred, u32 secid)
+static inline int security_kernel_act_as(struct cred *cred,
+					 struct lsmblob *blob)
 {
 	return 0;
 }
diff --git a/kernel/cred.c b/kernel/cred.c
index 45d77284aed0..71c14dda107e 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -701,14 +701,14 @@ EXPORT_SYMBOL(prepare_kernel_cred);
 /**
  * set_security_override - Set the security ID in a set of credentials
  * @new: The credentials to alter
- * @secid: The LSM security ID to set
+ * @blob: The LSM security information to set
  *
  * Set the LSM security ID in a set of credentials so that the subjective
  * security is overridden when an alternative set of credentials is used.
  */
-int set_security_override(struct cred *new, u32 secid)
+int set_security_override(struct cred *new, struct lsmblob *blob)
 {
-	return security_kernel_act_as(new, secid);
+	return security_kernel_act_as(new, blob);
 }
 EXPORT_SYMBOL(set_security_override);
 
@@ -724,6 +724,7 @@ EXPORT_SYMBOL(set_security_override);
  */
 int set_security_override_from_ctx(struct cred *new, const char *secctx)
 {
+	struct lsmblob blob;
 	u32 secid;
 	int ret;
 
@@ -731,7 +732,8 @@ int set_security_override_from_ctx(struct cred *new, const char *secctx)
 	if (ret < 0)
 		return ret;
 
-	return set_security_override(new, secid);
+	lsmblob_init(&blob, secid);
+	return set_security_override(new, &blob);
 }
 EXPORT_SYMBOL(set_security_override_from_ctx);
 
diff --git a/security/security.c b/security/security.c
index 4692f44718c6..43f8018b9e13 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1646,9 +1646,17 @@ void security_cred_getsecid(const struct cred *c, u32 *secid)
 }
 EXPORT_SYMBOL(security_cred_getsecid);
 
-int security_kernel_act_as(struct cred *new, u32 secid)
+int security_kernel_act_as(struct cred *new, struct lsmblob *blob)
 {
-	return call_int_hook(kernel_act_as, 0, new, secid);
+	struct security_hook_list *hp;
+	int rc;
+
+	hlist_for_each_entry(hp, &security_hook_heads.kernel_act_as, list) {
+		rc = hp->hook.kernel_act_as(new, blob->secid[hp->slot]);
+		if (rc != 0)
+			return rc;
+	}
+	return 0;
 }
 
 int security_kernel_create_files_as(struct cred *new, struct inode *inode)
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 07/24] net: Prepare UDS for secuirty module stacking
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (5 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 06/24] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:43   ` Kees Cook
  2019-06-24 18:39   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 08/24] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
                   ` (16 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Change the data used in UDS SO_PEERSEC processing from a
secid to a more general struct lsmblob. Update the
security_socket_getpeersec_dgram() interface to use the
lsmblob. There is a small amount of scaffolding code
that will come out when the security_secid_to_secctx()
code is brought in line with the lsmblob.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h |  7 +++++--
 include/net/af_unix.h    |  2 +-
 include/net/scm.h        |  8 +++++---
 net/ipv4/ip_sockglue.c   |  8 +++++---
 net/unix/af_unix.c       |  6 +++---
 security/security.c      | 16 +++++++++++++---
 6 files changed, 32 insertions(+), 15 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 4a78516cc74a..905830a90745 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1276,7 +1276,8 @@ int security_socket_shutdown(struct socket *sock, int how);
 int security_sock_rcv_skb(struct sock *sk, struct sk_buff *skb);
 int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
 				      int __user *optlen, unsigned len);
-int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid);
+int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
+				     struct lsmblob *blob);
 int security_sk_alloc(struct sock *sk, int family, gfp_t priority);
 void security_sk_free(struct sock *sk);
 void security_sk_clone(const struct sock *sk, struct sock *newsk);
@@ -1414,7 +1415,9 @@ static inline int security_socket_getpeersec_stream(struct socket *sock, char __
 	return -ENOPROTOOPT;
 }
 
-static inline int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
+static inline int security_socket_getpeersec_dgram(struct socket *sock,
+						   struct sk_buff *skb,
+						   struct lsmblob *blob)
 {
 	return -ENOPROTOOPT;
 }
diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index 3426d6dacc45..933492c08b8c 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -36,7 +36,7 @@ struct unix_skb_parms {
 	kgid_t			gid;
 	struct scm_fp_list	*fp;		/* Passed files		*/
 #ifdef CONFIG_SECURITY_NETWORK
-	u32			secid;		/* Security ID		*/
+	struct lsmblob		lsmblob;	/* Security LSM data	*/
 #endif
 	u32			consumed;
 } __randomize_layout;
diff --git a/include/net/scm.h b/include/net/scm.h
index 1ce365f4c256..e2e71c4bf9d0 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -33,7 +33,7 @@ struct scm_cookie {
 	struct scm_fp_list	*fp;		/* Passed files		*/
 	struct scm_creds	creds;		/* Skb credentials	*/
 #ifdef CONFIG_SECURITY_NETWORK
-	u32			secid;		/* Passed security ID 	*/
+	struct lsmblob		lsmblob;	/* Passed LSM data	*/
 #endif
 };
 
@@ -46,7 +46,7 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl);
 #ifdef CONFIG_SECURITY_NETWORK
 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
 {
-	security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
+	security_socket_getpeersec_dgram(sock, NULL, &scm->lsmblob);
 }
 #else
 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
@@ -97,7 +97,9 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
 	int err;
 
 	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
-		err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
+		/* Scaffolding - it has to be element 0 for now */
+		err = security_secid_to_secctx(scm->lsmblob.secid[0],
+					       &secdata, &seclen);
 
 		if (!err) {
 			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 82f341e84fae..2a5c868ce135 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -130,15 +130,17 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
 
 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 {
+	struct lsmblob lb;
 	char *secdata;
-	u32 seclen, secid;
+	u32 seclen;
 	int err;
 
-	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
+	err = security_socket_getpeersec_dgram(NULL, skb, &lb);
 	if (err)
 		return;
 
-	err = security_secid_to_secctx(secid, &secdata, &seclen);
+	/* Scaffolding - it has to be element 0 */
+	err = security_secid_to_secctx(lb.secid[0], &secdata, &seclen);
 	if (err)
 		return;
 
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index ddb838a1b74c..c50a004a1389 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -143,17 +143,17 @@ static struct hlist_head *unix_sockets_unbound(void *addr)
 #ifdef CONFIG_SECURITY_NETWORK
 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
 {
-	UNIXCB(skb).secid = scm->secid;
+	UNIXCB(skb).lsmblob = scm->lsmblob;
 }
 
 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
 {
-	scm->secid = UNIXCB(skb).secid;
+	scm->lsmblob = UNIXCB(skb).lsmblob;
 }
 
 static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
 {
-	return (scm->secid == UNIXCB(skb).secid);
+	return lsmblob_equal(&scm->lsmblob, &(UNIXCB(skb).lsmblob));
 }
 #else
 static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
diff --git a/security/security.c b/security/security.c
index 43f8018b9e13..c7b3d1a294ad 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2137,10 +2137,20 @@ int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
 				optval, optlen, len);
 }
 
-int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
+int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
+				     struct lsmblob *blob)
 {
-	return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock,
-			     skb, secid);
+	struct security_hook_list *hp;
+	int rc = -ENOPROTOOPT;
+
+	hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_dgram,
+			     list) {
+		rc = hp->hook.socket_getpeersec_dgram(sock, skb,
+						      &blob->secid[hp->slot]);
+		if (rc != 0)
+			break;
+	}
+	return rc;
 }
 EXPORT_SYMBOL(security_socket_getpeersec_dgram);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 08/24] LSM: Use lsmblob in security_secctx_to_secid
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (6 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 07/24] net: Prepare UDS for secuirty module stacking Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:44   ` Kees Cook
  2019-06-24 18:38   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 09/24] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
                   ` (15 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Change security_secctx_to_secid() to fill in a lsmblob instead
of a u32 secid. Multiple LSMs may be able to interpret the
string, and this allows for setting whichever secid is
appropriate. In some cases there is scaffolding where other
interfaces have yet to be converted.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h          |  5 +++--
 kernel/cred.c                     |  4 +---
 net/netfilter/nft_meta.c          | 13 ++++++-------
 net/netfilter/xt_SECMARK.c        |  5 ++++-
 net/netlabel/netlabel_unlabeled.c | 14 ++++++++------
 security/security.c               | 16 +++++++++++++---
 6 files changed, 35 insertions(+), 22 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 905830a90745..b0395d224c43 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -443,7 +443,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 int security_netlink_send(struct sock *sk, struct sk_buff *skb);
 int security_ismaclabel(const char *name);
 int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
-int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
+int security_secctx_to_secid(const char *secdata, u32 seclen,
+			     struct lsmblob *blob);
 void security_release_secctx(char *secdata, u32 seclen);
 
 void security_inode_invalidate_secctx(struct inode *inode);
@@ -1226,7 +1227,7 @@ static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *secle
 
 static inline int security_secctx_to_secid(const char *secdata,
 					   u32 seclen,
-					   u32 *secid)
+					   struct lsmblob *blob)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/kernel/cred.c b/kernel/cred.c
index 71c14dda107e..d70a2c02ced4 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -725,14 +725,12 @@ EXPORT_SYMBOL(set_security_override);
 int set_security_override_from_ctx(struct cred *new, const char *secctx)
 {
 	struct lsmblob blob;
-	u32 secid;
 	int ret;
 
-	ret = security_secctx_to_secid(secctx, strlen(secctx), &secid);
+	ret = security_secctx_to_secid(secctx, strlen(secctx), &blob);
 	if (ret < 0)
 		return ret;
 
-	lsmblob_init(&blob, secid);
 	return set_security_override(new, &blob);
 }
 EXPORT_SYMBOL(set_security_override_from_ctx);
diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
index 987d2d6ce624..91973d3a5f6a 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -576,21 +576,20 @@ static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = {
 
 static int nft_secmark_compute_secid(struct nft_secmark *priv)
 {
-	u32 tmp_secid = 0;
+	struct lsmblob blob;
 	int err;
 
-	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
+	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &blob);
 	if (err)
 		return err;
 
-	if (!tmp_secid)
-		return -ENOENT;
-
-	err = security_secmark_relabel_packet(tmp_secid);
+	/* Using le[0] is scaffolding */
+	err = security_secmark_relabel_packet(blob.secid[0]);
 	if (err)
 		return err;
 
-	priv->secid = tmp_secid;
+	/* Using le[1] is scaffolding */
+	priv->secid = blob.secid[0];
 	return 0;
 }
 
diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
index f16202d26c20..8081fadc30e9 100644
--- a/net/netfilter/xt_SECMARK.c
+++ b/net/netfilter/xt_SECMARK.c
@@ -49,13 +49,14 @@ secmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
 
 static int checkentry_lsm(struct xt_secmark_target_info *info)
 {
+	struct lsmblob blob;
 	int err;
 
 	info->secctx[SECMARK_SECCTX_MAX - 1] = '\0';
 	info->secid = 0;
 
 	err = security_secctx_to_secid(info->secctx, strlen(info->secctx),
-				       &info->secid);
+				       &blob);
 	if (err) {
 		if (err == -EINVAL)
 			pr_info_ratelimited("invalid security context \'%s\'\n",
@@ -63,6 +64,8 @@ static int checkentry_lsm(struct xt_secmark_target_info *info)
 		return err;
 	}
 
+	/* scaffolding during the transition */
+	info->secid = blob.secid[0];
 	if (!info->secid) {
 		pr_info_ratelimited("unable to map security context \'%s\'\n",
 				    info->secctx);
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index c92894c3e40a..2976370e41aa 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -895,7 +895,7 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
 	void *addr;
 	void *mask;
 	u32 addr_len;
-	u32 secid;
+	struct lsmblob blob;
 	struct netlbl_audit audit_info;
 
 	/* Don't allow users to add both IPv4 and IPv6 addresses for a
@@ -919,12 +919,13 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
 	ret_val = security_secctx_to_secid(
 		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
 				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
-				  &secid);
+				  &blob);
 	if (ret_val != 0)
 		return ret_val;
 
+	/* scaffolding with the [0] */
 	return netlbl_unlhsh_add(&init_net,
-				 dev_name, addr, mask, addr_len, secid,
+				 dev_name, addr, mask, addr_len, blob.secid[0],
 				 &audit_info);
 }
 
@@ -946,7 +947,7 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
 	void *addr;
 	void *mask;
 	u32 addr_len;
-	u32 secid;
+	struct lsmblob blob;
 	struct netlbl_audit audit_info;
 
 	/* Don't allow users to add both IPv4 and IPv6 addresses for a
@@ -968,12 +969,13 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
 	ret_val = security_secctx_to_secid(
 		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
 				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
-				  &secid);
+				  &blob);
 	if (ret_val != 0)
 		return ret_val;
 
+	/* scaffolding with the [0] */
 	return netlbl_unlhsh_add(&init_net,
-				 NULL, addr, mask, addr_len, secid,
+				 NULL, addr, mask, addr_len, blob.secid[0],
 				 &audit_info);
 }
 
diff --git a/security/security.c b/security/security.c
index c7b3d1a294ad..cb1545bfe8c5 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1999,10 +1999,20 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
 }
 EXPORT_SYMBOL(security_secid_to_secctx);
 
-int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
+int security_secctx_to_secid(const char *secdata, u32 seclen,
+			     struct lsmblob *blob)
 {
-	*secid = 0;
-	return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid);
+	struct security_hook_list *hp;
+	int rc;
+
+	lsmblob_init(blob, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
+		rc = hp->hook.secctx_to_secid(secdata, seclen,
+					      &blob->secid[hp->slot]);
+		if (rc != 0)
+			return rc;
+	}
+	return 0;
 }
 EXPORT_SYMBOL(security_secctx_to_secid);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 09/24] LSM: Use lsmblob in security_secid_to_secctx
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (7 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 08/24] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:44   ` Kees Cook
  2019-06-24 18:39   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 10/24] Use lsmblob in security_ipc_getsecid Casey Schaufler
                   ` (14 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Change security_secid_to_secctx() to take a lsmblob as input
instead of a u32 secid. It will then call the LSM hooks
using the lsmblob element allocated for that module. The
callers have been updated as well. This allows for the
possibility that more than one module may called upon
to translate a secid to a string, as can occur in the
audit code.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 drivers/android/binder.c                |  4 +++-
 include/linux/security.h                |  5 +++--
 include/net/scm.h                       |  5 ++---
 kernel/audit.c                          |  9 +++++++--
 kernel/auditsc.c                        | 14 ++++++++++----
 net/ipv4/ip_sockglue.c                  |  3 +--
 net/netfilter/nf_conntrack_netlink.c    |  8 ++++++--
 net/netfilter/nf_conntrack_standalone.c |  4 +++-
 net/netfilter/nfnetlink_queue.c         |  8 ++++++--
 net/netlabel/netlabel_unlabeled.c       | 18 ++++++++++++++----
 net/netlabel/netlabel_user.c            |  6 +++---
 security/security.c                     | 14 +++++++++++---
 12 files changed, 69 insertions(+), 29 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 8685882da64c..1962f6b8abd0 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3120,9 +3120,11 @@ static void binder_transaction(struct binder_proc *proc,
 
 	if (target_node && target_node->txn_security_ctx) {
 		u32 secid;
+		struct lsmblob blob;
 
 		security_task_getsecid(proc->tsk, &secid);
-		ret = security_secid_to_secctx(secid, &secctx, &secctx_sz);
+		lsmblob_init(&blob, secid);
+		ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
 		if (ret) {
 			return_error = BR_FAILED_REPLY;
 			return_error_param = ret;
diff --git a/include/linux/security.h b/include/linux/security.h
index b0395d224c43..c6cddeff8a17 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -442,7 +442,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 			 size_t size);
 int security_netlink_send(struct sock *sk, struct sk_buff *skb);
 int security_ismaclabel(const char *name);
-int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
+int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
 int security_secctx_to_secid(const char *secdata, u32 seclen,
 			     struct lsmblob *blob);
 void security_release_secctx(char *secdata, u32 seclen);
@@ -1220,7 +1220,8 @@ static inline int security_ismaclabel(const char *name)
 	return 0;
 }
 
-static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
+static inline int security_secid_to_secctx(struct lsmblob *blob,
+					   char **secdata, u32 *seclen)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/include/net/scm.h b/include/net/scm.h
index e2e71c4bf9d0..31ae605fcc0a 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -97,9 +97,8 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
 	int err;
 
 	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
-		/* Scaffolding - it has to be element 0 for now */
-		err = security_secid_to_secctx(scm->lsmblob.secid[0],
-					       &secdata, &seclen);
+		err = security_secid_to_secctx(&scm->lsmblob, &secdata,
+					       &seclen);
 
 		if (!err) {
 			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
diff --git a/kernel/audit.c b/kernel/audit.c
index c89ea48c70a6..d0338411d75d 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1430,7 +1430,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	case AUDIT_SIGNAL_INFO:
 		len = 0;
 		if (audit_sig_sid) {
-			err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
+			struct lsmblob blob;
+
+			lsmblob_init(&blob, audit_sig_sid);
+			err = security_secid_to_secctx(&blob, &ctx, &len);
 			if (err)
 				return err;
 		}
@@ -2073,12 +2076,14 @@ int audit_log_task_context(struct audit_buffer *ab)
 	unsigned len;
 	int error;
 	u32 sid;
+	struct lsmblob blob;
 
 	security_task_getsecid(current, &sid);
 	if (!sid)
 		return 0;
 
-	error = security_secid_to_secctx(sid, &ctx, &len);
+	lsmblob_init(&blob, sid);
+	error = security_secid_to_secctx(&blob, &ctx, &len);
 	if (error) {
 		if (error != -EINVAL)
 			goto error_path;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 18ee5556c086..d31914088a82 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -947,6 +947,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 	char *ctx = NULL;
 	u32 len;
 	int rc = 0;
+	struct lsmblob blob;
 
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
 	if (!ab)
@@ -956,7 +957,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 			 from_kuid(&init_user_ns, auid),
 			 from_kuid(&init_user_ns, uid), sessionid);
 	if (sid) {
-		if (security_secid_to_secctx(sid, &ctx, &len)) {
+		lsmblob_init(&blob, sid);
+		if (security_secid_to_secctx(&blob, &ctx, &len)) {
 			audit_log_format(ab, " obj=(none)");
 			rc = 1;
 		} else {
@@ -1198,7 +1200,10 @@ static void show_special(struct audit_context *context, int *call_panic)
 		if (osid) {
 			char *ctx = NULL;
 			u32 len;
-			if (security_secid_to_secctx(osid, &ctx, &len)) {
+			struct lsmblob blob;
+
+			lsmblob_init(&blob, osid);
+			if (security_secid_to_secctx(&blob, &ctx, &len)) {
 				audit_log_format(ab, " osid=%u", osid);
 				*call_panic = 1;
 			} else {
@@ -1349,9 +1354,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 	if (n->osid != 0) {
 		char *ctx = NULL;
 		u32 len;
+		struct lsmblob blob;
 
-		if (security_secid_to_secctx(
-			n->osid, &ctx, &len)) {
+		lsmblob_init(&blob, n->osid);
+		if (security_secid_to_secctx(&blob, &ctx, &len)) {
 			audit_log_format(ab, " osid=%u", n->osid);
 			if (call_panic)
 				*call_panic = 2;
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 2a5c868ce135..e05f4ef68bd8 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -139,8 +139,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 	if (err)
 		return;
 
-	/* Scaffolding - it has to be element 0 */
-	err = security_secid_to_secctx(lb.secid[0], &secdata, &seclen);
+	err = security_secid_to_secctx(&lb, &secdata, &seclen);
 	if (err)
 		return;
 
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 66c596d287a5..ca0968f13240 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -330,8 +330,10 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 	struct nlattr *nest_secctx;
 	int len, ret;
 	char *secctx;
+	struct lsmblob blob;
 
-	ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
+	lsmblob_init(&blob, ct->secmark);
+	ret = security_secid_to_secctx(&blob, &secctx, &len);
 	if (ret)
 		return 0;
 
@@ -615,8 +617,10 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
 {
 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 	int len, ret;
+	struct lsmblob blob;
 
-	ret = security_secid_to_secctx(ct->secmark, NULL, &len);
+	lsmblob_init(&blob, ct->secmark);
+	ret = security_secid_to_secctx(&blob, NULL, &len);
 	if (ret)
 		return 0;
 
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index c2ae14c720b4..c793103f3cd7 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -175,8 +175,10 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 	int ret;
 	u32 len;
 	char *secctx;
+	struct lsmblob blob;
 
-	ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
+	lsmblob_init(&blob, ct->secmark);
+	ret = security_secid_to_secctx(&blob, &secctx, &len);
 	if (ret)
 		return;
 
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 0dcc3592d053..59211bff90ab 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -309,13 +309,17 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
 {
 	u32 seclen = 0;
 #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
+	struct lsmblob blob;
+
 	if (!skb || !sk_fullsock(skb->sk))
 		return 0;
 
 	read_lock_bh(&skb->sk->sk_callback_lock);
 
-	if (skb->secmark)
-		security_secid_to_secctx(skb->secmark, secdata, &seclen);
+	if (skb->secmark) {
+		lsmblob_init(&blob, skb->secmark);
+		security_secid_to_secctx(&blob, secdata, &seclen);
+	}
 
 	read_unlock_bh(&skb->sk->sk_callback_lock);
 #endif
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 2976370e41aa..2d8dd5b84457 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -389,6 +389,7 @@ int netlbl_unlhsh_add(struct net *net,
 	struct audit_buffer *audit_buf = NULL;
 	char *secctx = NULL;
 	u32 secctx_len;
+	struct lsmblob blob;
 
 	if (addr_len != sizeof(struct in_addr) &&
 	    addr_len != sizeof(struct in6_addr))
@@ -451,7 +452,8 @@ int netlbl_unlhsh_add(struct net *net,
 unlhsh_add_return:
 	rcu_read_unlock();
 	if (audit_buf != NULL) {
-		if (security_secid_to_secctx(secid,
+		lsmblob_init(&blob, secid);
+		if (security_secid_to_secctx(&blob,
 					     &secctx,
 					     &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
@@ -488,6 +490,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 	struct net_device *dev;
 	char *secctx;
 	u32 secctx_len;
+	struct lsmblob blob;
 
 	spin_lock(&netlbl_unlhsh_lock);
 	list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
@@ -507,8 +510,10 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 					  addr->s_addr, mask->s_addr);
 		if (dev != NULL)
 			dev_put(dev);
+		if (entry != NULL)
+			lsmblob_init(&blob, entry->secid);
 		if (entry != NULL &&
-		    security_secid_to_secctx(entry->secid,
+		    security_secid_to_secctx(&blob,
 					     &secctx, &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
 			security_release_secctx(secctx, secctx_len);
@@ -550,6 +555,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 	struct net_device *dev;
 	char *secctx;
 	u32 secctx_len;
+	struct lsmblob blob;
 
 	spin_lock(&netlbl_unlhsh_lock);
 	list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
@@ -568,8 +574,10 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 					  addr, mask);
 		if (dev != NULL)
 			dev_put(dev);
+		if (entry != NULL)
+			lsmblob_init(&blob, entry->secid);
 		if (entry != NULL &&
-		    security_secid_to_secctx(entry->secid,
+		    security_secid_to_secctx(&blob,
 					     &secctx, &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
 			security_release_secctx(secctx, secctx_len);
@@ -1090,6 +1098,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 	u32 secid;
 	char *secctx;
 	u32 secctx_len;
+	struct lsmblob blob;
 
 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
 			   cb_arg->seq, &netlbl_unlabel_gnl_family,
@@ -1144,7 +1153,8 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 		secid = addr6->secid;
 	}
 
-	ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
+	lsmblob_init(&blob, secid);
+	ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
 	if (ret_val != 0)
 		goto list_cb_failure;
 	ret_val = nla_put(cb_arg->skb,
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 4676f5bb16ae..2ccc6567e2a2 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -100,6 +100,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 	struct audit_buffer *audit_buf;
 	char *secctx;
 	u32 secctx_len;
+	struct lsmblob blob;
 
 	if (audit_enabled == AUDIT_OFF)
 		return NULL;
@@ -112,10 +113,9 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 			 from_kuid(&init_user_ns, audit_info->loginuid),
 			 audit_info->sessionid);
 
+	lsmblob_init(&blob, audit_info->secid);
 	if (audit_info->secid != 0 &&
-	    security_secid_to_secctx(audit_info->secid,
-				     &secctx,
-				     &secctx_len) == 0) {
+	    security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
 		audit_log_format(audit_buf, " subj=%s", secctx);
 		security_release_secctx(secctx, secctx_len);
 	}
diff --git a/security/security.c b/security/security.c
index cb1545bfe8c5..5ab07631df75 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1992,10 +1992,18 @@ int security_ismaclabel(const char *name)
 }
 EXPORT_SYMBOL(security_ismaclabel);
 
-int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
+int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
 {
-	return call_int_hook(secid_to_secctx, -EOPNOTSUPP, secid, secdata,
-				seclen);
+	struct security_hook_list *hp;
+	int rc;
+
+	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
+		rc = hp->hook.secid_to_secctx(blob->secid[hp->slot],
+					      secdata, seclen);
+		if (rc != 0)
+			return rc;
+	}
+	return 0;
 }
 EXPORT_SYMBOL(security_secid_to_secctx);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 10/24] Use lsmblob in security_ipc_getsecid
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (8 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 09/24] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:48   ` Kees Cook
  2019-06-24 18:39   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 11/24] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
                   ` (13 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

There may be more than one LSM that provides IPC data
for auditing. Change security_ipc_getsecid() to fill in
a lsmblob structure instead of the u32 secid. The
audit data structure containing the secid will be updated
later, so there is a bit of scaffolding here.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h | 7 ++++---
 kernel/auditsc.c         | 5 ++++-
 security/security.c      | 9 ++++++---
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index c6cddeff8a17..0d5e172341fc 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -413,7 +413,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
 			unsigned long arg4, unsigned long arg5);
 void security_task_to_inode(struct task_struct *p, struct inode *inode);
 int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
-void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid);
+void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob);
 int security_msg_msg_alloc(struct msg_msg *msg);
 void security_msg_msg_free(struct msg_msg *msg);
 int security_msg_queue_alloc(struct kern_ipc_perm *msq);
@@ -1098,9 +1098,10 @@ static inline int security_ipc_permission(struct kern_ipc_perm *ipcp,
 	return 0;
 }
 
-static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp,
+					 struct lsmblob *blob)
 {
-	*secid = 0;
+	lsmblob_init(blob, 0);
 }
 
 static inline int security_msg_msg_alloc(struct msg_msg *msg)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index d31914088a82..148733ec3c72 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2268,11 +2268,14 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
 {
 	struct audit_context *context = audit_context();
+	struct lsmblob blob;
 	context->ipc.uid = ipcp->uid;
 	context->ipc.gid = ipcp->gid;
 	context->ipc.mode = ipcp->mode;
 	context->ipc.has_perm = 0;
-	security_ipc_getsecid(ipcp, &context->ipc.osid);
+	security_ipc_getsecid(ipcp, &blob);
+	/* scaffolding on the [0] - change "osid" to a lsmblob */
+	context->ipc.osid = blob.secid[0];
 	context->type = AUDIT_IPC;
 }
 
diff --git a/security/security.c b/security/security.c
index 5ab07631df75..d55f01041f05 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1812,10 +1812,13 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
 	return call_int_hook(ipc_permission, 0, ipcp, flag);
 }
 
-void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob)
 {
-	*secid = 0;
-	call_void_hook(ipc_getsecid, ipcp, secid);
+	struct security_hook_list *hp;
+
+	lsmblob_init(blob, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.ipc_getsecid, list)
+		hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->slot]);
 }
 
 int security_msg_msg_alloc(struct msg_msg *msg)
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 11/24] LSM: Use lsmblob in security_task_getsecid
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (9 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 10/24] Use lsmblob in security_ipc_getsecid Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:49   ` Kees Cook
  2019-06-24 18:40   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 12/24] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
                   ` (12 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Change the security_task_getsecid() interface to fill in
a lsmblob structure instead of a u32 secid in support of
LSM stacking. Audit interfaces will need to collect all
possible secids for possible reporting.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 drivers/android/binder.c              |  4 +---
 include/linux/security.h              |  7 +++---
 kernel/audit.c                        |  6 ++---
 kernel/auditfilter.c                  |  4 +---
 kernel/auditsc.c                      | 22 ++++++++++++------
 net/netlabel/netlabel_unlabeled.c     |  5 +++-
 net/netlabel/netlabel_user.h          |  6 ++++-
 security/integrity/ima/ima_appraise.c |  4 +++-
 security/integrity/ima/ima_main.c     | 33 +++++++++++++++------------
 security/security.c                   |  9 +++++---
 10 files changed, 60 insertions(+), 40 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 1962f6b8abd0..144ac4f1c24f 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3119,11 +3119,9 @@ static void binder_transaction(struct binder_proc *proc,
 	t->priority = task_nice(current);
 
 	if (target_node && target_node->txn_security_ctx) {
-		u32 secid;
 		struct lsmblob blob;
 
-		security_task_getsecid(proc->tsk, &secid);
-		lsmblob_init(&blob, secid);
+		security_task_getsecid(proc->tsk, &blob);
 		ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
 		if (ret) {
 			return_error = BR_FAILED_REPLY;
diff --git a/include/linux/security.h b/include/linux/security.h
index 0d5e172341fc..c5fdaaff8806 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -396,7 +396,7 @@ int security_task_fix_setuid(struct cred *new, const struct cred *old,
 int security_task_setpgid(struct task_struct *p, pid_t pgid);
 int security_task_getpgid(struct task_struct *p);
 int security_task_getsid(struct task_struct *p);
-void security_task_getsecid(struct task_struct *p, u32 *secid);
+void security_task_getsecid(struct task_struct *p, struct lsmblob *blob);
 int security_task_setnice(struct task_struct *p, int nice);
 int security_task_setioprio(struct task_struct *p, int ioprio);
 int security_task_getioprio(struct task_struct *p);
@@ -1025,9 +1025,10 @@ static inline int security_task_getsid(struct task_struct *p)
 	return 0;
 }
 
-static inline void security_task_getsecid(struct task_struct *p, u32 *secid)
+static inline void security_task_getsecid(struct task_struct *p,
+					  struct lsmblob *blob)
 {
-	*secid = 0;
+	lsmblob_init(blob, 0);
 }
 
 static inline int security_task_setnice(struct task_struct *p, int nice)
diff --git a/kernel/audit.c b/kernel/audit.c
index d0338411d75d..a0205f3c23c7 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2075,14 +2075,12 @@ int audit_log_task_context(struct audit_buffer *ab)
 	char *ctx = NULL;
 	unsigned len;
 	int error;
-	u32 sid;
 	struct lsmblob blob;
 
-	security_task_getsecid(current, &sid);
-	if (!sid)
+	security_task_getsecid(current, &blob);
+	if (!lsmblob_is_set(&blob))
 		return 0;
 
-	lsmblob_init(&blob, sid);
 	error = security_secid_to_secctx(&blob, &ctx, &len);
 	if (error) {
 		if (error != -EINVAL)
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index da211065160f..76b4c0ca4fd2 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1323,7 +1323,6 @@ int audit_filter(int msgtype, unsigned int listtype)
 		for (i = 0; i < e->rule.field_count; i++) {
 			struct audit_field *f = &e->rule.fields[i];
 			pid_t pid;
-			u32 sid;
 			struct lsmblob blob;
 
 			switch (f->type) {
@@ -1354,8 +1353,7 @@ int audit_filter(int msgtype, unsigned int listtype)
 			case AUDIT_SUBJ_SEN:
 			case AUDIT_SUBJ_CLR:
 				if (f->lsm_rule) {
-					security_task_getsecid(current, &sid);
-					lsmblob_init(&blob, sid);
+					security_task_getsecid(current, &blob);
 					result = security_audit_rule_match(&blob,
 						   f->type, f->op, f->lsm_rule);
 				}
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 148733ec3c72..7112fe31684d 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -444,7 +444,6 @@ static int audit_filter_rules(struct task_struct *tsk,
 {
 	const struct cred *cred;
 	int i, need_sid = 1;
-	u32 sid;
 	struct lsmblob blob;
 	unsigned int sessionid;
 
@@ -628,10 +627,9 @@ static int audit_filter_rules(struct task_struct *tsk,
 			   logged upon error */
 			if (f->lsm_rule) {
 				if (need_sid) {
-					security_task_getsecid(tsk, &sid);
+					security_task_getsecid(tsk, &blob);
 					need_sid = 0;
 				}
-				lsmblob_init(&blob, sid);
 				result = security_audit_rule_match(&blob,
 								   f->type,
 								   f->op,
@@ -2365,12 +2363,15 @@ int __audit_sockaddr(int len, void *a)
 void __audit_ptrace(struct task_struct *t)
 {
 	struct audit_context *context = audit_context();
+	struct lsmblob blob;
 
 	context->target_pid = task_tgid_nr(t);
 	context->target_auid = audit_get_loginuid(t);
 	context->target_uid = task_uid(t);
 	context->target_sessionid = audit_get_sessionid(t);
-	security_task_getsecid(t, &context->target_sid);
+	security_task_getsecid(t, &blob);
+	/* scaffolding - until target_sid is converted */
+	context->target_sid = blob.secid[0];
 	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
 }
 
@@ -2387,6 +2388,7 @@ int audit_signal_info(int sig, struct task_struct *t)
 	struct audit_aux_data_pids *axp;
 	struct audit_context *ctx = audit_context();
 	kuid_t uid = current_uid(), auid, t_uid = task_uid(t);
+	struct lsmblob blob;
 
 	if (auditd_test_task(t) &&
 	    (sig == SIGTERM || sig == SIGHUP ||
@@ -2397,7 +2399,9 @@ int audit_signal_info(int sig, struct task_struct *t)
 			audit_sig_uid = auid;
 		else
 			audit_sig_uid = uid;
-		security_task_getsecid(current, &audit_sig_sid);
+		security_task_getsecid(current, &blob);
+		/* scaffolding until audit_sig_sid is converted */
+		audit_sig_sid = blob.secid[0];
 	}
 
 	if (!audit_signals || audit_dummy_context())
@@ -2410,7 +2414,9 @@ int audit_signal_info(int sig, struct task_struct *t)
 		ctx->target_auid = audit_get_loginuid(t);
 		ctx->target_uid = t_uid;
 		ctx->target_sessionid = audit_get_sessionid(t);
-		security_task_getsecid(t, &ctx->target_sid);
+		security_task_getsecid(t, &blob);
+		/* scaffolding until target_sid is converted */
+		ctx->target_sid = blob.secid[0];
 		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
 		return 0;
 	}
@@ -2431,7 +2437,9 @@ int audit_signal_info(int sig, struct task_struct *t)
 	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
 	axp->target_uid[axp->pid_count] = t_uid;
 	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
-	security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
+	security_task_getsecid(t, &blob);
+	/* scaffolding until target_sid is converted */
+	axp->target_sid[axp->pid_count] = blob.secid[0];
 	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
 	axp->pid_count++;
 
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 2d8dd5b84457..2294aa9471e6 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -1552,11 +1552,14 @@ int __init netlbl_unlabel_defconf(void)
 	int ret_val;
 	struct netlbl_dom_map *entry;
 	struct netlbl_audit audit_info;
+	struct lsmblob blob;
 
 	/* Only the kernel is allowed to call this function and the only time
 	 * it is called is at bootup before the audit subsystem is reporting
 	 * messages so don't worry to much about these values. */
-	security_task_getsecid(current, &audit_info.secid);
+	security_task_getsecid(current, &blob);
+	/* scaffolding until audit_info.secid is converted */
+	audit_info.secid = blob.secid[0];
 	audit_info.loginuid = GLOBAL_ROOT_UID;
 	audit_info.sessionid = 0;
 
diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
index 4a397cde1a48..ab88baaaa50d 100644
--- a/net/netlabel/netlabel_user.h
+++ b/net/netlabel/netlabel_user.h
@@ -48,7 +48,11 @@
 static inline void netlbl_netlink_auditinfo(struct sk_buff *skb,
 					    struct netlbl_audit *audit_info)
 {
-	security_task_getsecid(current, &audit_info->secid);
+	struct lsmblob blob;
+
+	security_task_getsecid(current, &blob);
+	/* scaffolding until secid is converted */
+	audit_info->secid = blob.secid[0];
 	audit_info->loginuid = audit_get_loginuid(current);
 	audit_info->sessionid = audit_get_sessionid(current);
 }
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 5fb7127bbe68..85c7692fc4a3 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -51,11 +51,13 @@ bool is_ima_appraise_enabled(void)
 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
 {
 	u32 secid;
+	struct lsmblob blob;
 
 	if (!ima_appraise)
 		return 0;
 
-	security_task_getsecid(current, &secid);
+	security_task_getsecid(current, &blob);
+	lsmblob_secid(&blob, &secid);
 	return ima_match_policy(inode, current_cred(), secid, func, mask,
 				IMA_APPRAISE | IMA_HASH, NULL);
 }
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 357edd140c09..fefa848cf0c7 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -335,12 +335,13 @@ static int process_measurement(struct file *file, const struct cred *cred,
  */
 int ima_file_mmap(struct file *file, unsigned long prot)
 {
-	u32 secid;
+	struct lsmblob blob;
 
 	if (file && (prot & PROT_EXEC)) {
-		security_task_getsecid(current, &secid);
-		return process_measurement(file, current_cred(), secid, NULL,
-					   0, MAY_EXEC, MMAP_CHECK);
+		security_task_getsecid(current, &blob);
+		/* scaffolding - until process_measurement changes */
+		return process_measurement(file, current_cred(), blob.secid[0],
+					   NULL, 0, MAY_EXEC, MMAP_CHECK);
 	}
 
 	return 0;
@@ -363,10 +364,12 @@ int ima_bprm_check(struct linux_binprm *bprm)
 {
 	int ret;
 	u32 secid;
+	struct lsmblob blob;
 
-	security_task_getsecid(current, &secid);
-	ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0,
-				  MAY_EXEC, BPRM_CHECK);
+	security_task_getsecid(current, &blob);
+	/* scaffolding until process_measurement changes */
+	ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
+				  NULL, 0, MAY_EXEC, BPRM_CHECK);
 	if (ret)
 		return ret;
 
@@ -387,10 +390,11 @@ int ima_bprm_check(struct linux_binprm *bprm)
  */
 int ima_file_check(struct file *file, int mask)
 {
-	u32 secid;
+	struct lsmblob blob;
 
-	security_task_getsecid(current, &secid);
-	return process_measurement(file, current_cred(), secid, NULL, 0,
+	security_task_getsecid(current, &blob);
+	/* scaffolding until process_measurement changes */
+	return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
 				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
 					   MAY_APPEND), FILE_CHECK);
 }
@@ -499,7 +503,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
 		       enum kernel_read_file_id read_id)
 {
 	enum ima_hooks func;
-	u32 secid;
+	struct lsmblob blob;
 
 	if (!file && read_id == READING_FIRMWARE) {
 		if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
@@ -521,9 +525,10 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
 	}
 
 	func = read_idmap[read_id] ?: FILE_CHECK;
-	security_task_getsecid(current, &secid);
-	return process_measurement(file, current_cred(), secid, buf, size,
-				   MAY_READ, func);
+	security_task_getsecid(current, &blob);
+	/* scaffolding until process_measurement changes */
+	return process_measurement(file, current_cred(), blob.secid[0], buf,
+				   size, MAY_READ, func);
 }
 
 /**
diff --git a/security/security.c b/security/security.c
index d55f01041f05..1184ef092bce 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1729,10 +1729,13 @@ int security_task_getsid(struct task_struct *p)
 	return call_int_hook(task_getsid, 0, p);
 }
 
-void security_task_getsecid(struct task_struct *p, u32 *secid)
+void security_task_getsecid(struct task_struct *p, struct lsmblob *blob)
 {
-	*secid = 0;
-	call_void_hook(task_getsecid, p, secid);
+	struct security_hook_list *hp;
+
+	lsmblob_init(blob, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.task_getsecid, list)
+		hp->hook.task_getsecid(p, &blob->secid[hp->slot]);
 }
 EXPORT_SYMBOL(security_task_getsecid);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 12/24] LSM: Use lsmblob in security_inode_getsecid
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (10 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 11/24] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:49   ` Kees Cook
  2019-06-24 18:40   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 13/24] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
                   ` (11 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Change the security_inode_getsecid() interface to fill in a
lsmblob structure instead of a u32 secid. This allows for its
callers to gather data from all registered LSMs. Data is provided
for IMA and audit.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h            | 7 ++++---
 kernel/auditsc.c                    | 6 +++++-
 security/integrity/ima/ima_policy.c | 4 +---
 security/security.c                 | 8 ++++++--
 4 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index c5fdaaff8806..6eb64b7f878a 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -358,7 +358,7 @@ int security_inode_killpriv(struct dentry *dentry);
 int security_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc);
 int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags);
 int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size);
-void security_inode_getsecid(struct inode *inode, u32 *secid);
+void security_inode_getsecid(struct inode *inode, struct lsmblob *blob);
 int security_inode_copy_up(struct dentry *src, struct cred **new);
 int security_inode_copy_up_xattr(const char *name);
 int security_file_permission(struct file *file, int mask);
@@ -854,9 +854,10 @@ static inline int security_inode_listsecurity(struct inode *inode, char *buffer,
 	return 0;
 }
 
-static inline void security_inode_getsecid(struct inode *inode, u32 *secid)
+static inline void security_inode_getsecid(struct inode *inode,
+					   struct lsmblob *blob)
 {
-	*secid = 0;
+	lsmblob_init(blob, 0);
 }
 
 static inline int security_inode_copy_up(struct dentry *src, struct cred **new)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 7112fe31684d..54797c0fc3b7 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1910,13 +1910,17 @@ static inline int audit_copy_fcaps(struct audit_names *name,
 void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
 		      struct inode *inode, unsigned int flags)
 {
+	struct lsmblob blob;
+
 	name->ino   = inode->i_ino;
 	name->dev   = inode->i_sb->s_dev;
 	name->mode  = inode->i_mode;
 	name->uid   = inode->i_uid;
 	name->gid   = inode->i_gid;
 	name->rdev  = inode->i_rdev;
-	security_inode_getsecid(inode, &name->osid);
+	security_inode_getsecid(inode, &blob);
+	/* scaffolding until osid is updated */
+	name->osid = blob.secid[0];
 	if (flags & AUDIT_INODE_NOEVAL) {
 		name->fcap_ver = -1;
 		return;
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index e7b8ce942950..92ee3d984c73 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -326,7 +326,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 		return false;
 	for (i = 0; i < MAX_LSM_RULES; i++) {
 		int rc = 0;
-		u32 osid;
 		struct lsmblob blob;
 		int retried = 0;
 
@@ -337,8 +336,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 		case LSM_OBJ_USER:
 		case LSM_OBJ_ROLE:
 		case LSM_OBJ_TYPE:
-			security_inode_getsecid(inode, &osid);
-			lsmblob_init(&blob, osid);
+			security_inode_getsecid(inode, &blob);
 			rc = security_filter_rule_match(&blob,
 							rule->lsm[i].type,
 							Audit_equal,
diff --git a/security/security.c b/security/security.c
index 1184ef092bce..6f0635b51180 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1423,9 +1423,13 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer
 }
 EXPORT_SYMBOL(security_inode_listsecurity);
 
-void security_inode_getsecid(struct inode *inode, u32 *secid)
+void security_inode_getsecid(struct inode *inode, struct lsmblob *blob)
 {
-	call_void_hook(inode_getsecid, inode, secid);
+	struct security_hook_list *hp;
+
+	lsmblob_init(blob, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.inode_getsecid, list)
+		hp->hook.inode_getsecid(inode, &blob->secid[hp->slot]);
 }
 
 int security_inode_copy_up(struct dentry *src, struct cred **new)
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 13/24] LSM: Use lsmblob in security_cred_getsecid
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (11 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 12/24] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:50   ` Kees Cook
  2019-06-24 18:40   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 14/24] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
                   ` (10 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Change the security_cred_getsecid() interface to fill in a
lsmblob instead of a u32 secid. The associated data elements
in the audit sub-system are changed from a secid to a lsmblob
to accomodate multiple possible LSM audit users.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h          |  2 +-
 kernel/audit.c                    | 14 +++++-------
 kernel/audit.h                    |  5 +++--
 kernel/auditsc.c                  | 37 +++++++++++--------------------
 security/integrity/ima/ima_main.c |  8 +++----
 security/security.c               |  9 +++++---
 6 files changed, 33 insertions(+), 42 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 6eb64b7f878a..c712fc72b7bd 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -383,7 +383,7 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp);
 void security_cred_free(struct cred *cred);
 int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
 void security_transfer_creds(struct cred *new, const struct cred *old);
-void security_cred_getsecid(const struct cred *c, u32 *secid);
+void security_cred_getsecid(const struct cred *c, struct lsmblob *blob);
 int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
 int security_kernel_create_files_as(struct cred *new, struct inode *inode);
 int security_kernel_module_request(char *kmod_name);
diff --git a/kernel/audit.c b/kernel/audit.c
index a0205f3c23c7..1b51e907f131 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -137,7 +137,7 @@ static u32	audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
 /* The identity of the user shutting down the audit system. */
 kuid_t		audit_sig_uid = INVALID_UID;
 pid_t		audit_sig_pid = -1;
-u32		audit_sig_sid = 0;
+struct lsmblob	audit_sig_lsm;
 
 /* Records can be lost in several ways:
    0) [suppressed in audit_alloc]
@@ -1429,23 +1429,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	}
 	case AUDIT_SIGNAL_INFO:
 		len = 0;
-		if (audit_sig_sid) {
-			struct lsmblob blob;
-
-			lsmblob_init(&blob, audit_sig_sid);
-			err = security_secid_to_secctx(&blob, &ctx, &len);
+		if (lsmblob_is_set(&audit_sig_lsm)) {
+			err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
+						       &len);
 			if (err)
 				return err;
 		}
 		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
 		if (!sig_data) {
-			if (audit_sig_sid)
+			if (lsmblob_is_set(&audit_sig_lsm))
 				security_release_secctx(ctx, len);
 			return -ENOMEM;
 		}
 		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
 		sig_data->pid = audit_sig_pid;
-		if (audit_sig_sid) {
+		if (lsmblob_is_set(&audit_sig_lsm)) {
 			memcpy(sig_data->ctx, ctx, len);
 			security_release_secctx(ctx, len);
 		}
diff --git a/kernel/audit.h b/kernel/audit.h
index 958d5b8fc1b3..29e29c6f4afb 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -22,6 +22,7 @@
 #include <linux/fs.h>
 #include <linux/audit.h>
 #include <linux/skbuff.h>
+#include <linux/security.h>
 #include <uapi/linux/mqueue.h>
 #include <linux/tty.h>
 
@@ -147,7 +148,7 @@ struct audit_context {
 	kuid_t		    target_auid;
 	kuid_t		    target_uid;
 	unsigned int	    target_sessionid;
-	u32		    target_sid;
+	struct lsmblob   target_lsm;
 	char		    target_comm[TASK_COMM_LEN];
 
 	struct audit_tree_refs *trees, *first_trees;
@@ -338,7 +339,7 @@ extern char *audit_unpack_string(void **bufp, size_t *remain, size_t len);
 
 extern pid_t audit_sig_pid;
 extern kuid_t audit_sig_uid;
-extern u32 audit_sig_sid;
+extern struct lsmblob audit_sig_lsm;
 
 extern int audit_filter(int msgtype, unsigned int listtype);
 
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 54797c0fc3b7..c7aa39bda5cc 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -112,7 +112,7 @@ struct audit_aux_data_pids {
 	kuid_t			target_auid[AUDIT_AUX_PIDS];
 	kuid_t			target_uid[AUDIT_AUX_PIDS];
 	unsigned int		target_sessionid[AUDIT_AUX_PIDS];
-	u32			target_sid[AUDIT_AUX_PIDS];
+	struct lsmblob	target_lsm[AUDIT_AUX_PIDS];
 	char 			target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
 	int			pid_count;
 };
@@ -938,14 +938,14 @@ static inline void audit_free_context(struct audit_context *context)
 }
 
 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
-				 kuid_t auid, kuid_t uid, unsigned int sessionid,
-				 u32 sid, char *comm)
+				 kuid_t auid, kuid_t uid,
+				 unsigned int sessionid,
+				 struct lsmblob *blob, char *comm)
 {
 	struct audit_buffer *ab;
 	char *ctx = NULL;
 	u32 len;
 	int rc = 0;
-	struct lsmblob blob;
 
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
 	if (!ab)
@@ -954,9 +954,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
 			 from_kuid(&init_user_ns, auid),
 			 from_kuid(&init_user_ns, uid), sessionid);
-	if (sid) {
-		lsmblob_init(&blob, sid);
-		if (security_secid_to_secctx(&blob, &ctx, &len)) {
+	if (lsmblob_is_set(blob)) {
+		if (security_secid_to_secctx(blob, &ctx, &len)) {
 			audit_log_format(ab, " obj=(none)");
 			rc = 1;
 		} else {
@@ -1527,7 +1526,7 @@ static void audit_log_exit(void)
 						  axs->target_auid[i],
 						  axs->target_uid[i],
 						  axs->target_sessionid[i],
-						  axs->target_sid[i],
+						  &axs->target_lsm[i],
 						  axs->target_comm[i]))
 				call_panic = 1;
 	}
@@ -1536,7 +1535,7 @@ static void audit_log_exit(void)
 	    audit_log_pid_context(context, context->target_pid,
 				  context->target_auid, context->target_uid,
 				  context->target_sessionid,
-				  context->target_sid, context->target_comm))
+				  &context->target_lsm, context->target_comm))
 			call_panic = 1;
 
 	if (context->pwd.dentry && context->pwd.mnt) {
@@ -1713,7 +1712,7 @@ void __audit_syscall_exit(int success, long return_code)
 	context->aux = NULL;
 	context->aux_pids = NULL;
 	context->target_pid = 0;
-	context->target_sid = 0;
+	lsmblob_init(&context->target_lsm, 0);
 	context->sockaddr_len = 0;
 	context->type = 0;
 	context->fds[0] = -1;
@@ -2367,15 +2366,12 @@ int __audit_sockaddr(int len, void *a)
 void __audit_ptrace(struct task_struct *t)
 {
 	struct audit_context *context = audit_context();
-	struct lsmblob blob;
 
 	context->target_pid = task_tgid_nr(t);
 	context->target_auid = audit_get_loginuid(t);
 	context->target_uid = task_uid(t);
 	context->target_sessionid = audit_get_sessionid(t);
-	security_task_getsecid(t, &blob);
-	/* scaffolding - until target_sid is converted */
-	context->target_sid = blob.secid[0];
+	security_task_getsecid(t, &context->target_lsm);
 	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
 }
 
@@ -2392,7 +2388,6 @@ int audit_signal_info(int sig, struct task_struct *t)
 	struct audit_aux_data_pids *axp;
 	struct audit_context *ctx = audit_context();
 	kuid_t uid = current_uid(), auid, t_uid = task_uid(t);
-	struct lsmblob blob;
 
 	if (auditd_test_task(t) &&
 	    (sig == SIGTERM || sig == SIGHUP ||
@@ -2403,9 +2398,7 @@ int audit_signal_info(int sig, struct task_struct *t)
 			audit_sig_uid = auid;
 		else
 			audit_sig_uid = uid;
-		security_task_getsecid(current, &blob);
-		/* scaffolding until audit_sig_sid is converted */
-		audit_sig_sid = blob.secid[0];
+		security_task_getsecid(current, &audit_sig_lsm);
 	}
 
 	if (!audit_signals || audit_dummy_context())
@@ -2418,9 +2411,7 @@ int audit_signal_info(int sig, struct task_struct *t)
 		ctx->target_auid = audit_get_loginuid(t);
 		ctx->target_uid = t_uid;
 		ctx->target_sessionid = audit_get_sessionid(t);
-		security_task_getsecid(t, &blob);
-		/* scaffolding until target_sid is converted */
-		ctx->target_sid = blob.secid[0];
+		security_task_getsecid(t, &ctx->target_lsm);
 		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
 		return 0;
 	}
@@ -2441,9 +2432,7 @@ int audit_signal_info(int sig, struct task_struct *t)
 	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
 	axp->target_uid[axp->pid_count] = t_uid;
 	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
-	security_task_getsecid(t, &blob);
-	/* scaffolding until target_sid is converted */
-	axp->target_sid[axp->pid_count] = blob.secid[0];
+	security_task_getsecid(t, &axp->target_lsm[axp->pid_count]);
 	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
 	axp->pid_count++;
 
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index fefa848cf0c7..1afb75a893af 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -363,7 +363,6 @@ int ima_file_mmap(struct file *file, unsigned long prot)
 int ima_bprm_check(struct linux_binprm *bprm)
 {
 	int ret;
-	u32 secid;
 	struct lsmblob blob;
 
 	security_task_getsecid(current, &blob);
@@ -373,9 +372,10 @@ int ima_bprm_check(struct linux_binprm *bprm)
 	if (ret)
 		return ret;
 
-	security_cred_getsecid(bprm->cred, &secid);
-	return process_measurement(bprm->file, bprm->cred, secid, NULL, 0,
-				   MAY_EXEC, CREDS_CHECK);
+	security_cred_getsecid(bprm->cred, &blob);
+	/* scaffolding until process_measurement changes */
+	return process_measurement(bprm->file, bprm->cred, blob.secid[0],
+				   NULL, 0, MAY_EXEC, CREDS_CHECK);
 }
 
 /**
diff --git a/security/security.c b/security/security.c
index 6f0635b51180..aa8e1c73a062 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1643,10 +1643,13 @@ void security_transfer_creds(struct cred *new, const struct cred *old)
 	call_void_hook(cred_transfer, new, old);
 }
 
-void security_cred_getsecid(const struct cred *c, u32 *secid)
+void security_cred_getsecid(const struct cred *c, struct lsmblob *blob)
 {
-	*secid = 0;
-	call_void_hook(cred_getsecid, c, secid);
+	struct security_hook_list *hp;
+
+	lsmblob_init(blob, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.cred_getsecid, list)
+		hp->hook.cred_getsecid(c, &blob->secid[hp->slot]);
 }
 EXPORT_SYMBOL(security_cred_getsecid);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 14/24] IMA: Change internal interfaces to use lsmblobs
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (12 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 13/24] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:51   ` Kees Cook
  2019-06-24 18:40   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 15/24] LSM: Specify which LSM to display Casey Schaufler
                   ` (9 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

The IMA interfaces ima_get_action() and ima_match_policy()
call LSM functions that use lsmblobs. Change the IMA functions
to pass the lsmblob to be compatible with the LSM functions.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 security/integrity/ima/ima.h          | 10 ++++++----
 security/integrity/ima/ima_api.c      |  9 +++++----
 security/integrity/ima/ima_appraise.c |  4 +---
 security/integrity/ima/ima_main.c     | 27 +++++++++++----------------
 security/integrity/ima/ima_policy.c   | 12 ++++++------
 5 files changed, 29 insertions(+), 33 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 5a337239d9e4..73b3b15dec5c 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -192,8 +192,9 @@ enum ima_hooks {
 };
 
 /* LIM API function definitions */
-int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
-		   int mask, enum ima_hooks func, int *pcr);
+int ima_get_action(struct inode *inode, const struct cred *cred,
+		   struct lsmblob *blob, int mask, enum ima_hooks func,
+		   int *pcr);
 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
 int ima_collect_measurement(struct integrity_iint_cache *iint,
 			    struct file *file, void *buf, loff_t size,
@@ -213,8 +214,9 @@ void ima_free_template_entry(struct ima_template_entry *entry);
 const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
 
 /* IMA policy related functions */
-int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
-		     enum ima_hooks func, int mask, int flags, int *pcr);
+int ima_match_policy(struct inode *inode, const struct cred *cred,
+		     struct lsmblob *blob, enum ima_hooks func, int mask,
+		     int flags, int *pcr);
 void ima_init_policy(void);
 void ima_update_policy(void);
 void ima_update_policy_flag(void);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index c7505fb122d4..03a2392852de 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -159,7 +159,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
  * ima_get_action - appraise & measure decision based on policy.
  * @inode: pointer to inode to measure
  * @cred: pointer to credentials structure to validate
- * @secid: secid of the task being validated
+ * @blob: LAM data of the task being validated
  * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC,
  *        MAY_APPEND)
  * @func: caller identifier
@@ -175,14 +175,15 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
  * Returns IMA_MEASURE, IMA_APPRAISE mask.
  *
  */
-int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
-		   int mask, enum ima_hooks func, int *pcr)
+int ima_get_action(struct inode *inode, const struct cred *cred,
+		   struct lsmblob *blob, int mask, enum ima_hooks func,
+		   int *pcr)
 {
 	int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH;
 
 	flags &= ima_policy_flag;
 
-	return ima_match_policy(inode, cred, secid, func, mask, flags, pcr);
+	return ima_match_policy(inode, cred, blob, func, mask, flags, pcr);
 }
 
 /*
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 85c7692fc4a3..3ff7aae81829 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -50,15 +50,13 @@ bool is_ima_appraise_enabled(void)
  */
 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
 {
-	u32 secid;
 	struct lsmblob blob;
 
 	if (!ima_appraise)
 		return 0;
 
 	security_task_getsecid(current, &blob);
-	lsmblob_secid(&blob, &secid);
-	return ima_match_policy(inode, current_cred(), secid, func, mask,
+	return ima_match_policy(inode, current_cred(), &blob, func, mask,
 				IMA_APPRAISE | IMA_HASH, NULL);
 }
 
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 1afb75a893af..0588dd9a88db 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -169,8 +169,8 @@ void ima_file_free(struct file *file)
 }
 
 static int process_measurement(struct file *file, const struct cred *cred,
-			       u32 secid, char *buf, loff_t size, int mask,
-			       enum ima_hooks func)
+			       struct lsmblob *blob, char *buf, loff_t size,
+			       int mask, enum ima_hooks func)
 {
 	struct inode *inode = file_inode(file);
 	struct integrity_iint_cache *iint = NULL;
@@ -192,7 +192,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
 	 * bitmask based on the appraise/audit/measurement policy.
 	 * Included is the appraise submask.
 	 */
-	action = ima_get_action(inode, cred, secid, mask, func, &pcr);
+	action = ima_get_action(inode, cred, blob, mask, func, &pcr);
 	violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
 			   (ima_policy_flag & IMA_MEASURE));
 	if (!action && !violation_check)
@@ -339,8 +339,7 @@ int ima_file_mmap(struct file *file, unsigned long prot)
 
 	if (file && (prot & PROT_EXEC)) {
 		security_task_getsecid(current, &blob);
-		/* scaffolding - until process_measurement changes */
-		return process_measurement(file, current_cred(), blob.secid[0],
+		return process_measurement(file, current_cred(), &blob,
 					   NULL, 0, MAY_EXEC, MMAP_CHECK);
 	}
 
@@ -366,16 +365,14 @@ int ima_bprm_check(struct linux_binprm *bprm)
 	struct lsmblob blob;
 
 	security_task_getsecid(current, &blob);
-	/* scaffolding until process_measurement changes */
-	ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
-				  NULL, 0, MAY_EXEC, BPRM_CHECK);
+	ret = process_measurement(bprm->file, current_cred(), &blob, NULL, 0,
+				  MAY_EXEC, BPRM_CHECK);
 	if (ret)
 		return ret;
 
 	security_cred_getsecid(bprm->cred, &blob);
-	/* scaffolding until process_measurement changes */
-	return process_measurement(bprm->file, bprm->cred, blob.secid[0],
-				   NULL, 0, MAY_EXEC, CREDS_CHECK);
+	return process_measurement(bprm->file, bprm->cred, &blob, NULL, 0,
+				   MAY_EXEC, CREDS_CHECK);
 }
 
 /**
@@ -393,8 +390,7 @@ int ima_file_check(struct file *file, int mask)
 	struct lsmblob blob;
 
 	security_task_getsecid(current, &blob);
-	/* scaffolding until process_measurement changes */
-	return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
+	return process_measurement(file, current_cred(), &blob, NULL, 0,
 				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
 					   MAY_APPEND), FILE_CHECK);
 }
@@ -526,9 +522,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
 
 	func = read_idmap[read_id] ?: FILE_CHECK;
 	security_task_getsecid(current, &blob);
-	/* scaffolding until process_measurement changes */
-	return process_measurement(file, current_cred(), blob.secid[0], buf,
-				   size, MAY_READ, func);
+	return process_measurement(file, current_cred(), &blob, buf, size,
+				   MAY_READ, func);
 }
 
 /**
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 92ee3d984c73..dbad256aa7b4 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -286,7 +286,7 @@ static void ima_lsm_update_rules(void)
  * Returns true on rule match, false on failure.
  */
 static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
-			    const struct cred *cred, u32 secid,
+			    const struct cred *cred, struct lsmblob *blob,
 			    enum ima_hooks func, int mask)
 {
 	int i;
@@ -345,7 +345,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 		case LSM_SUBJ_USER:
 		case LSM_SUBJ_ROLE:
 		case LSM_SUBJ_TYPE:
-			lsmblob_init(&blob, secid);
 			rc = security_filter_rule_match(&blob,
 							rule->lsm[i].type,
 							Audit_equal,
@@ -394,7 +393,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
  * @inode: pointer to an inode for which the policy decision is being made
  * @cred: pointer to a credentials structure for which the policy decision is
  *        being made
- * @secid: LSM secid of the task to be validated
+ * @blob: LSM data of the task to be validated
  * @func: IMA hook identifier
  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
  * @pcr: set the pcr to extend
@@ -406,8 +405,9 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
  * list when walking it.  Reads are many orders of magnitude more numerous
  * than writes so ima_match_policy() is classical RCU candidate.
  */
-int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
-		     enum ima_hooks func, int mask, int flags, int *pcr)
+int ima_match_policy(struct inode *inode, const struct cred *cred,
+		     struct lsmblob *blob, enum ima_hooks func, int mask,
+		     int flags, int *pcr)
 {
 	struct ima_rule_entry *entry;
 	int action = 0, actmask = flags | (flags << 1);
@@ -418,7 +418,7 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
 		if (!(entry->action & actmask))
 			continue;
 
-		if (!ima_match_rules(entry, inode, cred, secid, func, mask))
+		if (!ima_match_rules(entry, inode, cred, blob, func, mask))
 			continue;
 
 		action |= entry->flags & IMA_ACTION_FLAGS;
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 15/24] LSM: Specify which LSM to display
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (13 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 14/24] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:51   ` Kees Cook
  2019-06-24 18:48   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 16/24] LSM: Ensure the correct LSM context releaser Casey Schaufler
                   ` (8 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Create a new entry "display" in /proc/.../attr for controlling
which LSM security information is displayed for a process.
The name of an active LSM that supplies hooks for human readable
data may be written to "display" to set the value. The name of
the LSM currently in use can be read from "display".
At this point there can only be one LSM capable of display
active.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 fs/proc/base.c      |   1 +
 security/security.c | 110 +++++++++++++++++++++++++++++++++++---------
 2 files changed, 90 insertions(+), 21 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index ddef482f1334..7bf70e041315 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2618,6 +2618,7 @@ static const struct pid_entry attr_dir_stuff[] = {
 	ATTR(NULL, "fscreate",		0666),
 	ATTR(NULL, "keycreate",		0666),
 	ATTR(NULL, "sockcreate",	0666),
+	ATTR(NULL, "display",		0666),
 #ifdef CONFIG_SECURITY_SMACK
 	DIR("smack",			0555,
 	    proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
diff --git a/security/security.c b/security/security.c
index aa8e1c73a062..92c5aa427b53 100644
--- a/security/security.c
+++ b/security/security.c
@@ -46,7 +46,9 @@ static struct kmem_cache *lsm_file_cache;
 static struct kmem_cache *lsm_inode_cache;
 
 char *lsm_names;
-static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init;
+static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init = {
+	.lbs_task = sizeof(int),	/* slot number for the "display" LSM */
+};
 
 /* Boot-time LSM user choice */
 static __initdata const char *chosen_lsm_order;
@@ -583,6 +585,8 @@ int lsm_inode_alloc(struct inode *inode)
  */
 static int lsm_task_alloc(struct task_struct *task)
 {
+	int *display;
+
 	if (blob_sizes.lbs_task == 0) {
 		task->security = NULL;
 		return 0;
@@ -591,6 +595,15 @@ static int lsm_task_alloc(struct task_struct *task)
 	task->security = kzalloc(blob_sizes.lbs_task, GFP_KERNEL);
 	if (task->security == NULL)
 		return -ENOMEM;
+
+	/*
+	 * The start of the task blob contains the "display" LSM slot number.
+	 * Start with it set to the invalid slot number, indicating that the
+	 * default first registered LSM be displayed.
+	 */
+	display = task->security;
+	*display = LSMBLOB_INVALID;
+
 	return 0;
 }
 
@@ -1579,14 +1592,24 @@ int security_file_open(struct file *file)
 
 int security_task_alloc(struct task_struct *task, unsigned long clone_flags)
 {
+	int *odisplay = current->security;
+	int *ndisplay;
 	int rc = lsm_task_alloc(task);
 
-	if (rc)
+	if (unlikely(rc))
 		return rc;
+
 	rc = call_int_hook(task_alloc, 0, task, clone_flags);
-	if (unlikely(rc))
+	if (unlikely(rc)) {
 		security_task_free(task);
-	return rc;
+		return rc;
+	}
+
+	ndisplay = task->security;
+	if (ndisplay && odisplay)
+		*ndisplay = *odisplay;
+
+	return 0;
 }
 
 void security_task_free(struct task_struct *task)
@@ -1972,10 +1995,28 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
 				char **value)
 {
 	struct security_hook_list *hp;
+	int *display = current->security;
+
+	if (!strcmp(name, "display")) {
+		hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx,
+				     list) {
+			if (*display == LSMBLOB_INVALID ||
+			    hp->slot == *display) {
+				*value = kstrdup(hp->lsm, GFP_KERNEL);
+				if (*value)
+					return strlen(hp->lsm);
+				return -ENOMEM;
+			}
+		}
+		return -EINVAL;
+	}
 
 	hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
 		if (lsm != NULL && strcmp(lsm, hp->lsm))
 			continue;
+		if (lsm == NULL && *display != LSMBLOB_INVALID &&
+		    *display != hp->slot)
+			continue;
 		return hp->hook.getprocattr(p, name, value);
 	}
 	return -EINVAL;
@@ -1985,10 +2026,27 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 			 size_t size)
 {
 	struct security_hook_list *hp;
+	int *display = current->security;
+	int len;
+
+	if (!strcmp(name, "display")) {
+		hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx,
+				     list) {
+			len = strlen(hp->lsm);
+			if (size >= len && !strncmp(value, hp->lsm, len)) {
+				*display = hp->slot;
+				return size;
+			}
+		}
+		return -EINVAL;
+	}
 
 	hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
 		if (lsm != NULL && strcmp(lsm, hp->lsm))
 			continue;
+		if (lsm == NULL && *display != LSMBLOB_INVALID &&
+		    *display != hp->slot)
+			continue;
 		return hp->hook.setprocattr(name, value, size);
 	}
 	return -EINVAL;
@@ -2008,14 +2066,12 @@ EXPORT_SYMBOL(security_ismaclabel);
 int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
 {
 	struct security_hook_list *hp;
-	int rc;
+	int *display = current->security;
 
-	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
-		rc = hp->hook.secid_to_secctx(blob->secid[hp->slot],
-					      secdata, seclen);
-		if (rc != 0)
-			return rc;
-	}
+	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list)
+		if (*display == LSMBLOB_INVALID || *display == hp->slot)
+			return hp->hook.secid_to_secctx(blob->secid[hp->slot],
+							secdata, seclen);
 	return 0;
 }
 EXPORT_SYMBOL(security_secid_to_secctx);
@@ -2024,22 +2080,27 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
 			     struct lsmblob *blob)
 {
 	struct security_hook_list *hp;
-	int rc;
+	int *display = current->security;
 
 	lsmblob_init(blob, 0);
-	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
-		rc = hp->hook.secctx_to_secid(secdata, seclen,
-					      &blob->secid[hp->slot]);
-		if (rc != 0)
-			return rc;
-	}
+	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list)
+		if (*display == LSMBLOB_INVALID || *display == hp->slot)
+			return hp->hook.secctx_to_secid(secdata, seclen,
+							&blob->secid[hp->slot]);
 	return 0;
 }
 EXPORT_SYMBOL(security_secctx_to_secid);
 
 void security_release_secctx(char *secdata, u32 seclen)
 {
-	call_void_hook(release_secctx, secdata, seclen);
+	struct security_hook_list *hp;
+	int *display = current->security;
+
+	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
+		if (*display == LSMBLOB_INVALID || *display == hp->slot) {
+			hp->hook.release_secctx(secdata, seclen);
+			return;
+		}
 }
 EXPORT_SYMBOL(security_release_secctx);
 
@@ -2164,8 +2225,15 @@ EXPORT_SYMBOL(security_sock_rcv_skb);
 int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
 				      int __user *optlen, unsigned len)
 {
-	return call_int_hook(socket_getpeersec_stream, -ENOPROTOOPT, sock,
-				optval, optlen, len);
+	int *display = current->security;
+	struct security_hook_list *hp;
+
+	hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_stream,
+			     list)
+		if (*display == LSMBLOB_INVALID || *display == hp->slot)
+			return hp->hook.socket_getpeersec_stream(sock, optval,
+								 optlen, len);
+	return -ENOPROTOOPT;
 }
 
 int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 16/24] LSM: Ensure the correct LSM context releaser
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (14 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 15/24] LSM: Specify which LSM to display Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:52   ` Kees Cook
  2019-06-24 21:46   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 17/24] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
                   ` (7 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Add a new lsmcontext data structure to hold all the information
about a "security context", including the string, its size and
which LSM allocated the string. The allocation information is
necessary because LSMs have different policies regarding the
lifecycle of these strings. SELinux allocates and destroys
them on each use, whereas Smack provides a pointer to an entry
in a list that never goes away.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 drivers/android/binder.c                | 10 +++++--
 fs/kernfs/dir.c                         |  9 ++++--
 fs/kernfs/inode.c                       |  7 +++--
 fs/nfs/nfs4proc.c                       |  8 +++--
 fs/nfsd/nfs4xdr.c                       |  7 +++--
 include/linux/security.h                | 39 +++++++++++++++++++++++--
 include/net/scm.h                       |  4 ++-
 kernel/audit.c                          | 14 ++++++---
 kernel/auditsc.c                        | 12 ++++++--
 net/ipv4/ip_sockglue.c                  |  4 ++-
 net/netfilter/nf_conntrack_netlink.c    |  4 ++-
 net/netfilter/nf_conntrack_standalone.c |  4 ++-
 net/netfilter/nfnetlink_queue.c         | 13 ++++++---
 net/netlabel/netlabel_unlabeled.c       | 19 +++++++++---
 net/netlabel/netlabel_user.c            |  4 ++-
 security/security.c                     | 12 +++++---
 security/smack/smack_lsm.c              | 14 ++++++---
 17 files changed, 142 insertions(+), 42 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 144ac4f1c24f..89e574be34cc 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2876,6 +2876,7 @@ static void binder_transaction(struct binder_proc *proc,
 	int t_debug_id = atomic_inc_return(&binder_last_id);
 	char *secctx = NULL;
 	u32 secctx_sz = 0;
+	struct lsmcontext scaff; /* scaffolding */
 
 	e = binder_transaction_log_add(&binder_transaction_log);
 	e->debug_id = t_debug_id;
@@ -3158,7 +3159,8 @@ static void binder_transaction(struct binder_proc *proc,
 		binder_alloc_copy_to_buffer(&target_proc->alloc,
 					    t->buffer, buf_offset,
 					    secctx, secctx_sz);
-		security_release_secctx(secctx, secctx_sz);
+		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
+		security_release_secctx(&scaff);
 		secctx = NULL;
 	}
 	t->buffer->debug_id = t->debug_id;
@@ -3479,8 +3481,10 @@ static void binder_transaction(struct binder_proc *proc,
 	t->buffer->transaction = NULL;
 	binder_alloc_free_buf(&target_proc->alloc, t->buffer);
 err_binder_alloc_buf_failed:
-	if (secctx)
-		security_release_secctx(secctx, secctx_sz);
+	if (secctx) {
+		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
+		security_release_secctx(&scaff);
+	}
 err_get_secctx_failed:
 	kfree(tcomplete);
 	binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index b84d635567d3..92afad387237 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -532,9 +532,12 @@ void kernfs_put(struct kernfs_node *kn)
 	kfree_const(kn->name);
 
 	if (kn->iattr) {
-		if (kn->iattr->ia_secdata)
-			security_release_secctx(kn->iattr->ia_secdata,
-						kn->iattr->ia_secdata_len);
+		struct lsmcontext scaff; /* scaffolding */
+		if (kn->iattr->ia_secdata) {
+			lsmcontext_init(&scaff, kn->iattr->ia_secdata,
+					kn->iattr->ia_secdata_len, 0);
+			security_release_secctx(&scaff);
+		}
 		simple_xattrs_free(&kn->iattr->xattrs);
 		kmem_cache_free(kernfs_iattrs_cache, kn->iattr);
 	}
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index 0c1fd945ce42..02cde9dac5ee 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -349,6 +349,7 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler,
 {
 	struct kernfs_node *kn = inode->i_private;
 	struct kernfs_iattrs *attrs;
+	struct lsmcontext context;
 	void *secdata;
 	u32 secdata_len = 0;
 	int error;
@@ -368,8 +369,10 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler,
 	error = kernfs_node_setsecdata(attrs, &secdata, &secdata_len);
 	mutex_unlock(&kernfs_mutex);
 
-	if (secdata)
-		security_release_secctx(secdata, secdata_len);
+	if (secdata) {
+		lsmcontext_init(&context, secdata, secdata_len, 0);
+		security_release_secctx(&context);
+	}
 	return error;
 }
 
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 4dbb0ee23432..af1c0db29c39 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -131,8 +131,12 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
 static inline void
 nfs4_label_release_security(struct nfs4_label *label)
 {
-	if (label)
-		security_release_secctx(label->label, label->len);
+	struct lsmcontext scaff; /* scaffolding */
+
+	if (label) {
+		lsmcontext_init(&scaff, label->label, label->len, 0);
+		security_release_secctx(&scaff);
+	}
 }
 static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label)
 {
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 3de42a729093..bb3db033e144 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2420,6 +2420,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 	__be32 status;
 	int err;
 	struct nfs4_acl *acl = NULL;
+	struct lsmcontext scaff; /* scaffolding */
 	void *context = NULL;
 	int contextlen;
 	bool contextsupport = false;
@@ -2919,8 +2920,10 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 
 out:
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
-	if (context)
-		security_release_secctx(context, contextlen);
+	if (context) {
+		lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/
+		security_release_secctx(&scaff);
+	}
 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
 	kfree(acl);
 	if (tempfh) {
diff --git a/include/linux/security.h b/include/linux/security.h
index c712fc72b7bd..ddf6d7cb23f1 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -76,6 +76,41 @@ enum lsm_event {
 	LSM_POLICY_CHANGE,
 };
 
+/*
+ * A "security context" is the text representation of
+ * the information used by LSMs.
+ * This structure contains the string, its length, and which LSM
+ * it is useful for.
+ */
+struct lsmcontext {
+	char	*context;	/* Provided by the module */
+	u32	len;
+	int	slot;		/* Identifies the module */
+};
+
+/**
+ * lsmcontext_init - initialize an lsmcontext structure.
+ * @cp: Pointer to the context to initialize
+ * @context: Initial context, or NULL
+ * @size: Size of context, or 0
+ * @slot: Which LSM provided the context
+ *
+ * Fill in the lsmcontext from the provided information.
+ * This is a scaffolding function that will be removed when
+ * lsmcontext integration is complete.
+ */
+static inline void lsmcontext_init(struct lsmcontext *cp, char *context,
+				   u32 size, int slot)
+{
+	cp->slot = slot;
+	cp->context = context;
+
+	if (context == NULL || size == 0)
+		cp->len = 0;
+	else
+		cp->len = strlen(context);
+}
+
 /*
  * Data exported by the security modules
  */
@@ -445,7 +480,7 @@ int security_ismaclabel(const char *name);
 int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
 int security_secctx_to_secid(const char *secdata, u32 seclen,
 			     struct lsmblob *blob);
-void security_release_secctx(char *secdata, u32 seclen);
+void security_release_secctx(struct lsmcontext *cp);
 
 void security_inode_invalidate_secctx(struct inode *inode);
 int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
@@ -1236,7 +1271,7 @@ static inline int security_secctx_to_secid(const char *secdata,
 	return -EOPNOTSUPP;
 }
 
-static inline void security_release_secctx(char *secdata, u32 seclen)
+static inline void security_release_secctx(struct lsmcontext *cp)
 {
 }
 
diff --git a/include/net/scm.h b/include/net/scm.h
index 31ae605fcc0a..6c7c3c229e4a 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -92,6 +92,7 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
 #ifdef CONFIG_SECURITY_NETWORK
 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
 {
+	struct lsmcontext context;
 	char *secdata;
 	u32 seclen;
 	int err;
@@ -102,7 +103,8 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
 
 		if (!err) {
 			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
-			security_release_secctx(secdata, seclen);
+			lsmcontext_init(&context, secdata, seclen, 0);/*scaffolding*/
+			security_release_secctx(&context);
 		}
 	}
 }
diff --git a/kernel/audit.c b/kernel/audit.c
index 1b51e907f131..f844a2a642e6 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1193,6 +1193,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	struct audit_sig_info   *sig_data;
 	char			*ctx = NULL;
 	u32			len;
+	struct lsmcontext	scaff; /* scaffolding */
 
 	err = audit_netlink_ok(skb, msg_type);
 	if (err)
@@ -1437,15 +1438,18 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		}
 		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
 		if (!sig_data) {
-			if (lsmblob_is_set(&audit_sig_lsm))
-				security_release_secctx(ctx, len);
+			if (lsmblob_is_set(&audit_sig_lsm)) {
+				lsmcontext_init(&scaff, ctx, len, 0);
+				security_release_secctx(&scaff);
+			}
 			return -ENOMEM;
 		}
 		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
 		sig_data->pid = audit_sig_pid;
 		if (lsmblob_is_set(&audit_sig_lsm)) {
 			memcpy(sig_data->ctx, ctx, len);
-			security_release_secctx(ctx, len);
+			lsmcontext_init(&scaff, ctx, len, 0);
+			security_release_secctx(&scaff);
 		}
 		audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
 				 sig_data, sizeof(*sig_data) + len);
@@ -2074,6 +2078,7 @@ int audit_log_task_context(struct audit_buffer *ab)
 	unsigned len;
 	int error;
 	struct lsmblob blob;
+	struct lsmcontext scaff; /* scaffolding */
 
 	security_task_getsecid(current, &blob);
 	if (!lsmblob_is_set(&blob))
@@ -2087,7 +2092,8 @@ int audit_log_task_context(struct audit_buffer *ab)
 	}
 
 	audit_log_format(ab, " subj=%s", ctx);
-	security_release_secctx(ctx, len);
+	lsmcontext_init(&scaff, ctx, len, 0);
+	security_release_secctx(&scaff);
 	return 0;
 
 error_path:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index c7aa39bda5cc..9fab0e7d90c3 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -943,6 +943,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 				 struct lsmblob *blob, char *comm)
 {
 	struct audit_buffer *ab;
+	struct lsmcontext lsmcxt;
 	char *ctx = NULL;
 	u32 len;
 	int rc = 0;
@@ -960,7 +961,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 			rc = 1;
 		} else {
 			audit_log_format(ab, " obj=%s", ctx);
-			security_release_secctx(ctx, len);
+			lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/
+			security_release_secctx(&lsmcxt);
 		}
 	}
 	audit_log_format(ab, " ocomm=");
@@ -1172,6 +1174,7 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
 
 static void show_special(struct audit_context *context, int *call_panic)
 {
+	struct lsmcontext lsmcxt;
 	struct audit_buffer *ab;
 	int i;
 
@@ -1205,7 +1208,8 @@ static void show_special(struct audit_context *context, int *call_panic)
 				*call_panic = 1;
 			} else {
 				audit_log_format(ab, " obj=%s", ctx);
-				security_release_secctx(ctx, len);
+				lsmcontext_init(&lsmcxt, ctx, len, 0);
+				security_release_secctx(&lsmcxt);
 			}
 		}
 		if (context->ipc.has_perm) {
@@ -1352,6 +1356,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 		char *ctx = NULL;
 		u32 len;
 		struct lsmblob blob;
+		struct lsmcontext lsmcxt;
 
 		lsmblob_init(&blob, n->osid);
 		if (security_secid_to_secctx(&blob, &ctx, &len)) {
@@ -1360,7 +1365,8 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 				*call_panic = 2;
 		} else {
 			audit_log_format(ab, " obj=%s", ctx);
-			security_release_secctx(ctx, len);
+			lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */
+			security_release_secctx(&lsmcxt);
 		}
 	}
 
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index e05f4ef68bd8..7834c357b60b 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -130,6 +130,7 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
 
 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 {
+	struct lsmcontext context;
 	struct lsmblob lb;
 	char *secdata;
 	u32 seclen;
@@ -144,7 +145,8 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 		return;
 
 	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
-	security_release_secctx(secdata, seclen);
+	lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */
+	security_release_secctx(&context);
 }
 
 static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index ca0968f13240..6954e6600583 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -331,6 +331,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 	int len, ret;
 	char *secctx;
 	struct lsmblob blob;
+	struct lsmcontext context;
 
 	lsmblob_init(&blob, ct->secmark);
 	ret = security_secid_to_secctx(&blob, &secctx, &len);
@@ -348,7 +349,8 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 
 	ret = 0;
 nla_put_failure:
-	security_release_secctx(secctx, len);
+	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
+	security_release_secctx(&context);
 	return ret;
 }
 #else
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index c793103f3cd7..79158ad0486e 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -176,6 +176,7 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 	u32 len;
 	char *secctx;
 	struct lsmblob blob;
+	struct lsmcontext context;
 
 	lsmblob_init(&blob, ct->secmark);
 	ret = security_secid_to_secctx(&blob, &secctx, &len);
@@ -184,7 +185,8 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 
 	seq_printf(s, "secctx=%s ", secctx);
 
-	security_release_secctx(secctx, len);
+	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
+	security_release_secctx(&context);
 }
 #else
 static inline void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 59211bff90ab..fe8403ef4e89 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -399,6 +399,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	enum ip_conntrack_info uninitialized_var(ctinfo);
 	struct nfnl_ct_hook *nfnl_ct;
 	bool csum_verify;
+	struct lsmcontext scaff; /* scaffolding */
 	char *secdata = NULL;
 	u32 seclen = 0;
 
@@ -629,8 +630,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	}
 
 	nlh->nlmsg_len = skb->len;
-	if (seclen)
-		security_release_secctx(secdata, seclen);
+	if (seclen) {
+		lsmcontext_init(&scaff, secdata, seclen, 0);
+		security_release_secctx(&scaff);
+	}
 	return skb;
 
 nla_put_failure:
@@ -638,8 +641,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	kfree_skb(skb);
 	net_err_ratelimited("nf_queue: error creating packet message\n");
 nlmsg_failure:
-	if (seclen)
-		security_release_secctx(secdata, seclen);
+	if (seclen) {
+		lsmcontext_init(&scaff, secdata, seclen, 0);
+		security_release_secctx(&scaff);
+	}
 	return NULL;
 }
 
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 2294aa9471e6..15b1945853be 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -387,6 +387,7 @@ int netlbl_unlhsh_add(struct net *net,
 	struct net_device *dev;
 	struct netlbl_unlhsh_iface *iface;
 	struct audit_buffer *audit_buf = NULL;
+	struct lsmcontext context;
 	char *secctx = NULL;
 	u32 secctx_len;
 	struct lsmblob blob;
@@ -457,7 +458,9 @@ int netlbl_unlhsh_add(struct net *net,
 					     &secctx,
 					     &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
-			security_release_secctx(secctx, secctx_len);
+			/* scaffolding */
+			lsmcontext_init(&context, secctx, secctx_len, 0);
+			security_release_secctx(&context);
 		}
 		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
 		audit_log_end(audit_buf);
@@ -488,6 +491,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 	struct netlbl_unlhsh_addr4 *entry;
 	struct audit_buffer *audit_buf;
 	struct net_device *dev;
+	struct lsmcontext context;
 	char *secctx;
 	u32 secctx_len;
 	struct lsmblob blob;
@@ -516,7 +520,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 		    security_secid_to_secctx(&blob,
 					     &secctx, &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
-			security_release_secctx(secctx, secctx_len);
+			/* scaffolding */
+			lsmcontext_init(&context, secctx, secctx_len, 0);
+			security_release_secctx(&context);
 		}
 		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
 		audit_log_end(audit_buf);
@@ -553,6 +559,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 	struct netlbl_unlhsh_addr6 *entry;
 	struct audit_buffer *audit_buf;
 	struct net_device *dev;
+	struct lsmcontext context;
 	char *secctx;
 	u32 secctx_len;
 	struct lsmblob blob;
@@ -580,7 +587,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 		    security_secid_to_secctx(&blob,
 					     &secctx, &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
-			security_release_secctx(secctx, secctx_len);
+			lsmcontext_init(&context, secctx, secctx_len, 0);
+			security_release_secctx(&context);
 		}
 		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
 		audit_log_end(audit_buf);
@@ -1094,6 +1102,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 	int ret_val = -ENOMEM;
 	struct netlbl_unlhsh_walk_arg *cb_arg = arg;
 	struct net_device *dev;
+	struct lsmcontext context;
 	void *data;
 	u32 secid;
 	char *secctx;
@@ -1161,7 +1170,9 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 			  NLBL_UNLABEL_A_SECCTX,
 			  secctx_len,
 			  secctx);
-	security_release_secctx(secctx, secctx_len);
+	/* scaffolding */
+	lsmcontext_init(&context, secctx, secctx_len, 0);
+	security_release_secctx(&context);
 	if (ret_val != 0)
 		goto list_cb_failure;
 
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 2ccc6567e2a2..94aea4985b74 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -98,6 +98,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 					       struct netlbl_audit *audit_info)
 {
 	struct audit_buffer *audit_buf;
+	struct lsmcontext context;
 	char *secctx;
 	u32 secctx_len;
 	struct lsmblob blob;
@@ -117,7 +118,8 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 	if (audit_info->secid != 0 &&
 	    security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
 		audit_log_format(audit_buf, " subj=%s", secctx);
-		security_release_secctx(secctx, secctx_len);
+		lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/
+		security_release_secctx(&context);
 	}
 
 	return audit_buf;
diff --git a/security/security.c b/security/security.c
index 92c5aa427b53..d5f173e85393 100644
--- a/security/security.c
+++ b/security/security.c
@@ -460,6 +460,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
 		    hooks[i].head == &security_hook_heads.setprocattr ||
 		    hooks[i].head == &security_hook_heads.secctx_to_secid ||
 		    hooks[i].head == &security_hook_heads.secid_to_secctx ||
+		    hooks[i].head == &security_hook_heads.release_secctx ||
 		    hooks[i].head == &security_hook_heads.ipc_getsecid ||
 		    hooks[i].head == &security_hook_heads.task_getsecid ||
 		    hooks[i].head == &security_hook_heads.inode_getsecid ||
@@ -2091,16 +2092,19 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
 }
 EXPORT_SYMBOL(security_secctx_to_secid);
 
-void security_release_secctx(char *secdata, u32 seclen)
+void security_release_secctx(struct lsmcontext *cp)
 {
 	struct security_hook_list *hp;
-	int *display = current->security;
 
 	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
-		if (*display == LSMBLOB_INVALID || *display == hp->slot) {
-			hp->hook.release_secctx(secdata, seclen);
+		if (cp->slot == hp->slot) {
+			hp->hook.release_secctx(cp->context, cp->len);
+			memset(cp, 0, sizeof(*cp));
 			return;
 		}
+
+	pr_warn("%s context \"%s\" from slot %d not released\n", __func__,
+		cp->context, cp->slot);
 }
 EXPORT_SYMBOL(security_release_secctx);
 
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index e9560b078efe..3834b751d1e9 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4439,11 +4439,16 @@ static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
 	return 0;
 }
 
-/*
- * There used to be a smack_release_secctx hook
- * that did nothing back when hooks were in a vector.
- * Now that there's a list such a hook adds cost.
+/**
+ * smack_release_secctx - do everything necessary to free a context
+ * @secdata: Unused
+ * @seclen: Unused
+ *
+ * Do nothing but hold a slot in the hooks list.
  */
+static void smack_release_secctx(char *secdata, u32 seclen)
+{
+}
 
 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
 {
@@ -4683,6 +4688,7 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(ismaclabel, smack_ismaclabel),
 	LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx),
 	LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid),
+	LSM_HOOK_INIT(release_secctx, smack_release_secctx),
 	LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx),
 	LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx),
 	LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx),
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 17/24] LSM: Use lsmcontext in security_secid_to_secctx
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (15 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 16/24] LSM: Ensure the correct LSM context releaser Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:52   ` Kees Cook
  2019-06-24 21:46   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 18/24] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
                   ` (6 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Replace the (secctx,seclen) pointer pair with a single
lsmcontext pointer to allow return of the LSM identifier
along with the context and context length. This allows
security_release_secctx() to know how to release the
context. Callers have been modified to use or save the
returned data from the new structure.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 drivers/android/binder.c                | 24 ++++++---------
 include/linux/security.h                |  4 +--
 include/net/scm.h                       |  9 ++----
 kernel/audit.c                          | 29 +++++++-----------
 kernel/auditsc.c                        | 31 +++++++------------
 net/ipv4/ip_sockglue.c                  |  7 ++---
 net/netfilter/nf_conntrack_netlink.c    | 14 +++++----
 net/netfilter/nf_conntrack_standalone.c |  7 ++---
 net/netfilter/nfnetlink_queue.c         |  5 +++-
 net/netlabel/netlabel_unlabeled.c       | 40 ++++++++-----------------
 net/netlabel/netlabel_user.c            |  7 ++---
 security/security.c                     |  9 +++---
 12 files changed, 71 insertions(+), 115 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 89e574be34cc..5d417a7b9bb3 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2874,9 +2874,7 @@ static void binder_transaction(struct binder_proc *proc,
 	binder_size_t last_fixup_min_off = 0;
 	struct binder_context *context = proc->context;
 	int t_debug_id = atomic_inc_return(&binder_last_id);
-	char *secctx = NULL;
-	u32 secctx_sz = 0;
-	struct lsmcontext scaff; /* scaffolding */
+	struct lsmcontext lsmctx;
 
 	e = binder_transaction_log_add(&binder_transaction_log);
 	e->debug_id = t_debug_id;
@@ -3123,14 +3121,14 @@ static void binder_transaction(struct binder_proc *proc,
 		struct lsmblob blob;
 
 		security_task_getsecid(proc->tsk, &blob);
-		ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
+		ret = security_secid_to_secctx(&blob, &lsmctx);
 		if (ret) {
 			return_error = BR_FAILED_REPLY;
 			return_error_param = ret;
 			return_error_line = __LINE__;
 			goto err_get_secctx_failed;
 		}
-		extra_buffers_size += ALIGN(secctx_sz, sizeof(u64));
+		extra_buffers_size += ALIGN(lsmctx.len, sizeof(u64));
 	}
 
 	trace_binder_transaction(reply, t, target_node);
@@ -3149,19 +3147,17 @@ static void binder_transaction(struct binder_proc *proc,
 		t->buffer = NULL;
 		goto err_binder_alloc_buf_failed;
 	}
-	if (secctx) {
+	if (lsmctx.context) {
 		size_t buf_offset = ALIGN(tr->data_size, sizeof(void *)) +
 				    ALIGN(tr->offsets_size, sizeof(void *)) +
 				    ALIGN(extra_buffers_size, sizeof(void *)) -
-				    ALIGN(secctx_sz, sizeof(u64));
+				    ALIGN(lsmctx.len, sizeof(u64));
 
 		t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset;
 		binder_alloc_copy_to_buffer(&target_proc->alloc,
 					    t->buffer, buf_offset,
-					    secctx, secctx_sz);
-		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
-		security_release_secctx(&scaff);
-		secctx = NULL;
+					    lsmctx.context, lsmctx.len);
+		security_release_secctx(&lsmctx);
 	}
 	t->buffer->debug_id = t->debug_id;
 	t->buffer->transaction = t;
@@ -3481,10 +3477,8 @@ static void binder_transaction(struct binder_proc *proc,
 	t->buffer->transaction = NULL;
 	binder_alloc_free_buf(&target_proc->alloc, t->buffer);
 err_binder_alloc_buf_failed:
-	if (secctx) {
-		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
-		security_release_secctx(&scaff);
-	}
+	if (lsmctx.context)
+		security_release_secctx(&lsmctx);
 err_get_secctx_failed:
 	kfree(tcomplete);
 	binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
diff --git a/include/linux/security.h b/include/linux/security.h
index ddf6d7cb23f1..3cbe43db16f5 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -477,7 +477,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 			 size_t size);
 int security_netlink_send(struct sock *sk, struct sk_buff *skb);
 int security_ismaclabel(const char *name);
-int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
 int security_secctx_to_secid(const char *secdata, u32 seclen,
 			     struct lsmblob *blob);
 void security_release_secctx(struct lsmcontext *cp);
@@ -1259,7 +1259,7 @@ static inline int security_ismaclabel(const char *name)
 }
 
 static inline int security_secid_to_secctx(struct lsmblob *blob,
-					   char **secdata, u32 *seclen)
+					   struct lsmcontext *cp)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/include/net/scm.h b/include/net/scm.h
index 6c7c3c229e4a..4a6ad8caf423 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -93,17 +93,14 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
 static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
 {
 	struct lsmcontext context;
-	char *secdata;
-	u32 seclen;
 	int err;
 
 	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
-		err = security_secid_to_secctx(&scm->lsmblob, &secdata,
-					       &seclen);
+		err = security_secid_to_secctx(&scm->lsmblob, &context);
 
 		if (!err) {
-			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
-			lsmcontext_init(&context, secdata, seclen, 0);/*scaffolding*/
+			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY,
+				 context.len, context.context);
 			security_release_secctx(&context);
 		}
 	}
diff --git a/kernel/audit.c b/kernel/audit.c
index f844a2a642e6..436c23429319 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1191,9 +1191,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	struct audit_buffer	*ab;
 	u16			msg_type = nlh->nlmsg_type;
 	struct audit_sig_info   *sig_data;
-	char			*ctx = NULL;
 	u32			len;
-	struct lsmcontext	scaff; /* scaffolding */
+	struct lsmcontext	context;
 
 	err = audit_netlink_ok(skb, msg_type);
 	if (err)
@@ -1431,25 +1430,22 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	case AUDIT_SIGNAL_INFO:
 		len = 0;
 		if (lsmblob_is_set(&audit_sig_lsm)) {
-			err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
-						       &len);
+			err = security_secid_to_secctx(&audit_sig_lsm,
+						       &context);
 			if (err)
 				return err;
 		}
 		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
 		if (!sig_data) {
-			if (lsmblob_is_set(&audit_sig_lsm)) {
-				lsmcontext_init(&scaff, ctx, len, 0);
-				security_release_secctx(&scaff);
-			}
+			if (lsmblob_is_set(&audit_sig_lsm))
+				security_release_secctx(&context);
 			return -ENOMEM;
 		}
 		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
 		sig_data->pid = audit_sig_pid;
 		if (lsmblob_is_set(&audit_sig_lsm)) {
-			memcpy(sig_data->ctx, ctx, len);
-			lsmcontext_init(&scaff, ctx, len, 0);
-			security_release_secctx(&scaff);
+			memcpy(sig_data->ctx, context.context, context.len);
+			security_release_secctx(&context);
 		}
 		audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
 				 sig_data, sizeof(*sig_data) + len);
@@ -2074,26 +2070,23 @@ void audit_log_key(struct audit_buffer *ab, char *key)
 
 int audit_log_task_context(struct audit_buffer *ab)
 {
-	char *ctx = NULL;
-	unsigned len;
 	int error;
 	struct lsmblob blob;
-	struct lsmcontext scaff; /* scaffolding */
+	struct lsmcontext context;
 
 	security_task_getsecid(current, &blob);
 	if (!lsmblob_is_set(&blob))
 		return 0;
 
-	error = security_secid_to_secctx(&blob, &ctx, &len);
+	error = security_secid_to_secctx(&blob, &context);
 	if (error) {
 		if (error != -EINVAL)
 			goto error_path;
 		return 0;
 	}
 
-	audit_log_format(ab, " subj=%s", ctx);
-	lsmcontext_init(&scaff, ctx, len, 0);
-	security_release_secctx(&scaff);
+	audit_log_format(ab, " subj=%s", context.context);
+	security_release_secctx(&context);
 	return 0;
 
 error_path:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 9fab0e7d90c3..0478680cd0a8 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -943,9 +943,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 				 struct lsmblob *blob, char *comm)
 {
 	struct audit_buffer *ab;
-	struct lsmcontext lsmcxt;
-	char *ctx = NULL;
-	u32 len;
+	struct lsmcontext lsmctx;
 	int rc = 0;
 
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
@@ -956,13 +954,12 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 			 from_kuid(&init_user_ns, auid),
 			 from_kuid(&init_user_ns, uid), sessionid);
 	if (lsmblob_is_set(blob)) {
-		if (security_secid_to_secctx(blob, &ctx, &len)) {
+		if (security_secid_to_secctx(blob, &lsmctx)) {
 			audit_log_format(ab, " obj=(none)");
 			rc = 1;
 		} else {
-			audit_log_format(ab, " obj=%s", ctx);
-			lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/
-			security_release_secctx(&lsmcxt);
+			audit_log_format(ab, " obj=%s", lsmctx.context);
+			security_release_secctx(&lsmctx);
 		}
 	}
 	audit_log_format(ab, " ocomm=");
@@ -1174,7 +1171,6 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
 
 static void show_special(struct audit_context *context, int *call_panic)
 {
-	struct lsmcontext lsmcxt;
 	struct audit_buffer *ab;
 	int i;
 
@@ -1198,17 +1194,15 @@ static void show_special(struct audit_context *context, int *call_panic)
 				 from_kgid(&init_user_ns, context->ipc.gid),
 				 context->ipc.mode);
 		if (osid) {
-			char *ctx = NULL;
-			u32 len;
+			struct lsmcontext lsmcxt;
 			struct lsmblob blob;
 
 			lsmblob_init(&blob, osid);
-			if (security_secid_to_secctx(&blob, &ctx, &len)) {
+			if (security_secid_to_secctx(&blob, &lsmcxt)) {
 				audit_log_format(ab, " osid=%u", osid);
 				*call_panic = 1;
 			} else {
-				audit_log_format(ab, " obj=%s", ctx);
-				lsmcontext_init(&lsmcxt, ctx, len, 0);
+				audit_log_format(ab, " obj=%s", lsmcxt.context);
 				security_release_secctx(&lsmcxt);
 			}
 		}
@@ -1353,20 +1347,17 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 				 MAJOR(n->rdev),
 				 MINOR(n->rdev));
 	if (n->osid != 0) {
-		char *ctx = NULL;
-		u32 len;
 		struct lsmblob blob;
-		struct lsmcontext lsmcxt;
+		struct lsmcontext lsmctx;
 
 		lsmblob_init(&blob, n->osid);
-		if (security_secid_to_secctx(&blob, &ctx, &len)) {
+		if (security_secid_to_secctx(&blob, &lsmctx)) {
 			audit_log_format(ab, " osid=%u", n->osid);
 			if (call_panic)
 				*call_panic = 2;
 		} else {
-			audit_log_format(ab, " obj=%s", ctx);
-			lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */
-			security_release_secctx(&lsmcxt);
+			audit_log_format(ab, " obj=%s", lsmctx.context);
+			security_release_secctx(&lsmctx);
 		}
 	}
 
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 7834c357b60b..80ae0c5a1301 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -132,20 +132,17 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 {
 	struct lsmcontext context;
 	struct lsmblob lb;
-	char *secdata;
-	u32 seclen;
 	int err;
 
 	err = security_socket_getpeersec_dgram(NULL, skb, &lb);
 	if (err)
 		return;
 
-	err = security_secid_to_secctx(&lb, &secdata, &seclen);
+	err = security_secid_to_secctx(&lb, &context);
 	if (err)
 		return;
 
-	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
-	lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */
+	put_cmsg(msg, SOL_IP, SCM_SECURITY, context.len, context.context);
 	security_release_secctx(&context);
 }
 
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 6954e6600583..403307ff0fff 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -328,13 +328,12 @@ static int ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct)
 static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 {
 	struct nlattr *nest_secctx;
-	int len, ret;
-	char *secctx;
+	int ret;
 	struct lsmblob blob;
 	struct lsmcontext context;
 
 	lsmblob_init(&blob, ct->secmark);
-	ret = security_secid_to_secctx(&blob, &secctx, &len);
+	ret = security_secid_to_secctx(&blob, &context);
 	if (ret)
 		return 0;
 
@@ -343,13 +342,12 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 	if (!nest_secctx)
 		goto nla_put_failure;
 
-	if (nla_put_string(skb, CTA_SECCTX_NAME, secctx))
+	if (nla_put_string(skb, CTA_SECCTX_NAME, context.context))
 		goto nla_put_failure;
 	nla_nest_end(skb, nest_secctx);
 
 	ret = 0;
 nla_put_failure:
-	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
 	security_release_secctx(&context);
 	return ret;
 }
@@ -620,12 +618,16 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 	int len, ret;
 	struct lsmblob blob;
+	struct lsmcontext context;
 
 	lsmblob_init(&blob, ct->secmark);
-	ret = security_secid_to_secctx(&blob, NULL, &len);
+	ret = security_secid_to_secctx(&blob, &context);
 	if (ret)
 		return 0;
 
+	len = context.len;
+	security_release_secctx(&context);
+
 	return nla_total_size(0) /* CTA_SECCTX */
 	       + nla_total_size(sizeof(char) * len); /* CTA_SECCTX_NAME */
 #else
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 79158ad0486e..fcb51ab2bb8b 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -173,19 +173,16 @@ static void ct_seq_stop(struct seq_file *s, void *v)
 static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 {
 	int ret;
-	u32 len;
-	char *secctx;
 	struct lsmblob blob;
 	struct lsmcontext context;
 
 	lsmblob_init(&blob, ct->secmark);
-	ret = security_secid_to_secctx(&blob, &secctx, &len);
+	ret = security_secid_to_secctx(&blob, &context);
 	if (ret)
 		return;
 
-	seq_printf(s, "secctx=%s ", secctx);
+	seq_printf(s, "secctx=%s ", context.context);
 
-	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
 	security_release_secctx(&context);
 }
 #else
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index fe8403ef4e89..6da00c7add5b 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -310,6 +310,7 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
 	u32 seclen = 0;
 #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
 	struct lsmblob blob;
+	struct lsmcontext context;
 
 	if (!skb || !sk_fullsock(skb->sk))
 		return 0;
@@ -318,10 +319,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
 
 	if (skb->secmark) {
 		lsmblob_init(&blob, skb->secmark);
-		security_secid_to_secctx(&blob, secdata, &seclen);
+		security_secid_to_secctx(&blob, &context);
+		*secdata = context.context;
 	}
 
 	read_unlock_bh(&skb->sk->sk_callback_lock);
+	seclen = context.len;
 #endif
 	return seclen;
 }
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 15b1945853be..4716e0011ba5 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -388,8 +388,6 @@ int netlbl_unlhsh_add(struct net *net,
 	struct netlbl_unlhsh_iface *iface;
 	struct audit_buffer *audit_buf = NULL;
 	struct lsmcontext context;
-	char *secctx = NULL;
-	u32 secctx_len;
 	struct lsmblob blob;
 
 	if (addr_len != sizeof(struct in_addr) &&
@@ -454,12 +452,9 @@ int netlbl_unlhsh_add(struct net *net,
 	rcu_read_unlock();
 	if (audit_buf != NULL) {
 		lsmblob_init(&blob, secid);
-		if (security_secid_to_secctx(&blob,
-					     &secctx,
-					     &secctx_len) == 0) {
-			audit_log_format(audit_buf, " sec_obj=%s", secctx);
-			/* scaffolding */
-			lsmcontext_init(&context, secctx, secctx_len, 0);
+		if (security_secid_to_secctx(&blob, &context) == 0) {
+			audit_log_format(audit_buf, " sec_obj=%s",
+					 context.context);
 			security_release_secctx(&context);
 		}
 		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
@@ -492,8 +487,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 	struct audit_buffer *audit_buf;
 	struct net_device *dev;
 	struct lsmcontext context;
-	char *secctx;
-	u32 secctx_len;
 	struct lsmblob blob;
 
 	spin_lock(&netlbl_unlhsh_lock);
@@ -517,11 +510,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 		if (entry != NULL)
 			lsmblob_init(&blob, entry->secid);
 		if (entry != NULL &&
-		    security_secid_to_secctx(&blob,
-					     &secctx, &secctx_len) == 0) {
-			audit_log_format(audit_buf, " sec_obj=%s", secctx);
-			/* scaffolding */
-			lsmcontext_init(&context, secctx, secctx_len, 0);
+		    security_secid_to_secctx(&blob, &context) == 0) {
+			audit_log_format(audit_buf, " sec_obj=%s",
+					 context.context);
 			security_release_secctx(&context);
 		}
 		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
@@ -560,8 +551,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 	struct audit_buffer *audit_buf;
 	struct net_device *dev;
 	struct lsmcontext context;
-	char *secctx;
-	u32 secctx_len;
 	struct lsmblob blob;
 
 	spin_lock(&netlbl_unlhsh_lock);
@@ -584,10 +573,9 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 		if (entry != NULL)
 			lsmblob_init(&blob, entry->secid);
 		if (entry != NULL &&
-		    security_secid_to_secctx(&blob,
-					     &secctx, &secctx_len) == 0) {
-			audit_log_format(audit_buf, " sec_obj=%s", secctx);
-			lsmcontext_init(&context, secctx, secctx_len, 0);
+		    security_secid_to_secctx(&blob, &context) == 0) {
+			audit_log_format(audit_buf, " sec_obj=%s",
+					 context.context);
 			security_release_secctx(&context);
 		}
 		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
@@ -1105,8 +1093,6 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 	struct lsmcontext context;
 	void *data;
 	u32 secid;
-	char *secctx;
-	u32 secctx_len;
 	struct lsmblob blob;
 
 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
@@ -1163,15 +1149,13 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 	}
 
 	lsmblob_init(&blob, secid);
-	ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
+	ret_val = security_secid_to_secctx(&blob, &context);
 	if (ret_val != 0)
 		goto list_cb_failure;
 	ret_val = nla_put(cb_arg->skb,
 			  NLBL_UNLABEL_A_SECCTX,
-			  secctx_len,
-			  secctx);
-	/* scaffolding */
-	lsmcontext_init(&context, secctx, secctx_len, 0);
+			  context.len,
+			  context.context);
 	security_release_secctx(&context);
 	if (ret_val != 0)
 		goto list_cb_failure;
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 94aea4985b74..2d1307f65250 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -99,8 +99,6 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 {
 	struct audit_buffer *audit_buf;
 	struct lsmcontext context;
-	char *secctx;
-	u32 secctx_len;
 	struct lsmblob blob;
 
 	if (audit_enabled == AUDIT_OFF)
@@ -116,9 +114,8 @@ struct audit_buffer *netlbl_audit_start_common(int type,
 
 	lsmblob_init(&blob, audit_info->secid);
 	if (audit_info->secid != 0 &&
-	    security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
-		audit_log_format(audit_buf, " subj=%s", secctx);
-		lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/
+	    security_secid_to_secctx(&blob, &context) == 0) {
+		audit_log_format(audit_buf, " subj=%s", context.context);
 		security_release_secctx(&context);
 	}
 
diff --git a/security/security.c b/security/security.c
index d5f173e85393..f461ab3fb9c4 100644
--- a/security/security.c
+++ b/security/security.c
@@ -459,7 +459,6 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
 		    hooks[i].head == &security_hook_heads.getprocattr ||
 		    hooks[i].head == &security_hook_heads.setprocattr ||
 		    hooks[i].head == &security_hook_heads.secctx_to_secid ||
-		    hooks[i].head == &security_hook_heads.secid_to_secctx ||
 		    hooks[i].head == &security_hook_heads.release_secctx ||
 		    hooks[i].head == &security_hook_heads.ipc_getsecid ||
 		    hooks[i].head == &security_hook_heads.task_getsecid ||
@@ -2064,15 +2063,17 @@ int security_ismaclabel(const char *name)
 }
 EXPORT_SYMBOL(security_ismaclabel);
 
-int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
 {
 	struct security_hook_list *hp;
 	int *display = current->security;
 
 	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list)
-		if (*display == LSMBLOB_INVALID || *display == hp->slot)
+		if (*display == LSMBLOB_INVALID || *display == hp->slot) {
+			cp->slot = hp->slot;
 			return hp->hook.secid_to_secctx(blob->secid[hp->slot],
-							secdata, seclen);
+							&cp->context, &cp->len);
+		}
 	return 0;
 }
 EXPORT_SYMBOL(security_secid_to_secctx);
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 18/24] LSM: Use lsmcontext in security_dentry_init_security
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (16 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 17/24] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:54   ` Kees Cook
  2019-06-24 21:46   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 19/24] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
                   ` (5 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Change the security_dentry_init_security() interface to
fill an lsmcontext structure instead of a void * data area
and a length. The lone caller of this interface is NFS4,
which may make copies of the data using its own mechanisms.
A rework of the nfs4 code to use the lsmcontext properly
is a significant project, so the coward's way out is taken,
and the lsmcontext data from security_dentry_init_security()
is copied, then released directly.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 fs/nfs/nfs4proc.c        | 26 ++++++++++++++++----------
 include/linux/security.h |  7 +++----
 security/security.c      | 20 ++++++++++++++++----
 3 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index af1c0db29c39..952f805965bb 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -113,6 +113,7 @@ static inline struct nfs4_label *
 nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
 	struct iattr *sattr, struct nfs4_label *label)
 {
+	struct lsmcontext context;
 	int err;
 
 	if (label == NULL)
@@ -122,21 +123,26 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
 		return NULL;
 
 	err = security_dentry_init_security(dentry, sattr->ia_mode,
-				&dentry->d_name, (void **)&label->label, &label->len);
-	if (err == 0)
-		return label;
+					    &dentry->d_name, &context);
+
+	if (err)
+		return NULL;
+
+	label->label = kmemdup(context.context, context.len, GFP_KERNEL);
+	if (label->label == NULL)
+		label = NULL;
+	else
+		label->len = context.len;
+
+	security_release_secctx(&context);
+
+	return label;
 
-	return NULL;
 }
 static inline void
 nfs4_label_release_security(struct nfs4_label *label)
 {
-	struct lsmcontext scaff; /* scaffolding */
-
-	if (label) {
-		lsmcontext_init(&scaff, label->label, label->len, 0);
-		security_release_secctx(&scaff);
-	}
+	kfree(label->label);
 }
 static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label)
 {
diff --git a/include/linux/security.h b/include/linux/security.h
index 3cbe43db16f5..2a2785a4e752 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -348,8 +348,8 @@ int security_sb_clone_mnt_opts(const struct super_block *oldsb,
 int security_add_mnt_opt(const char *option, const char *val,
 				int len, void **mnt_opts);
 int security_dentry_init_security(struct dentry *dentry, int mode,
-					const struct qstr *name, void **ctx,
-					u32 *ctxlen);
+					const struct qstr *name,
+					struct lsmcontext *ctx);
 int security_dentry_create_files_as(struct dentry *dentry, int mode,
 					struct qstr *name,
 					const struct cred *old,
@@ -720,8 +720,7 @@ static inline void security_inode_free(struct inode *inode)
 static inline int security_dentry_init_security(struct dentry *dentry,
 						 int mode,
 						 const struct qstr *name,
-						 void **ctx,
-						 u32 *ctxlen)
+						 struct lsmcontext *ctx)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/security/security.c b/security/security.c
index f461ab3fb9c4..842ac65abc08 100644
--- a/security/security.c
+++ b/security/security.c
@@ -453,6 +453,8 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
 		 * secid in the lsmblob structure.
 		 */
 		if (hooks[i].head == &security_hook_heads.audit_rule_match ||
+		    hooks[i].head ==
+			&security_hook_heads.dentry_init_security ||
 		    hooks[i].head == &security_hook_heads.kernel_act_as ||
 		    hooks[i].head ==
 			&security_hook_heads.socket_getpeersec_dgram ||
@@ -1040,11 +1042,21 @@ void security_inode_free(struct inode *inode)
 }
 
 int security_dentry_init_security(struct dentry *dentry, int mode,
-					const struct qstr *name, void **ctx,
-					u32 *ctxlen)
+				  const struct qstr *name,
+				  struct lsmcontext *cp)
 {
-	return call_int_hook(dentry_init_security, -EOPNOTSUPP, dentry, mode,
-				name, ctx, ctxlen);
+	int *display = current->security;
+	struct security_hook_list *hp;
+
+	hlist_for_each_entry(hp, &security_hook_heads.dentry_init_security,
+			     list)
+		if (*display == 0 || *display == hp->slot) {
+			cp->slot = hp->slot;
+			return hp->hook.dentry_init_security(dentry, mode,
+					name, (void **)&cp->context, &cp->len);
+		}
+
+	return -EOPNOTSUPP;
 }
 EXPORT_SYMBOL(security_dentry_init_security);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 19/24] LSM: Use lsmcontext in security_inode_getsecctx
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (17 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 18/24] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:56   ` Kees Cook
  2019-06-24 21:46   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 20/24] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
                   ` (4 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Change the security_inode_getsecctx() interface to fill
a lsmcontext structure instead of data and length pointers.
This provides the information about which LSM created the
context so that security_release_secctx() can use the
correct hook. A lsmcontext is used within kernfs to store
the security information as well.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 fs/kernfs/dir.c             |  8 ++------
 fs/kernfs/inode.c           | 34 ++++++++++++----------------------
 fs/kernfs/kernfs-internal.h |  3 +--
 fs/nfsd/nfs4xdr.c           | 23 +++++++++--------------
 include/linux/security.h    |  5 +++--
 security/security.c         | 13 +++++++++++--
 6 files changed, 38 insertions(+), 48 deletions(-)

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 92afad387237..1d000289d8b7 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -532,12 +532,8 @@ void kernfs_put(struct kernfs_node *kn)
 	kfree_const(kn->name);
 
 	if (kn->iattr) {
-		struct lsmcontext scaff; /* scaffolding */
-		if (kn->iattr->ia_secdata) {
-			lsmcontext_init(&scaff, kn->iattr->ia_secdata,
-					kn->iattr->ia_secdata_len, 0);
-			security_release_secctx(&scaff);
-		}
+		if (kn->iattr->ia_context.context)
+			security_release_secctx(&kn->iattr->ia_context);
 		simple_xattrs_free(&kn->iattr->xattrs);
 		kmem_cache_free(kernfs_iattrs_cache, kn->iattr);
 	}
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index 02cde9dac5ee..ffbf7863306d 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -135,21 +135,14 @@ int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr)
 	return error;
 }
 
-static int kernfs_node_setsecdata(struct kernfs_iattrs *attrs, void **secdata,
-				  u32 *secdata_len)
+static void kernfs_node_setsecdata(struct kernfs_iattrs *attrs,
+				   struct lsmcontext *cp)
 {
-	void *old_secdata;
-	size_t old_secdata_len;
+	struct lsmcontext old_context;
 
-	old_secdata = attrs->ia_secdata;
-	old_secdata_len = attrs->ia_secdata_len;
-
-	attrs->ia_secdata = *secdata;
-	attrs->ia_secdata_len = *secdata_len;
-
-	*secdata = old_secdata;
-	*secdata_len = old_secdata_len;
-	return 0;
+	old_context = attrs->ia_context;
+	attrs->ia_context = *cp;
+	*cp = old_context;
 }
 
 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size)
@@ -192,8 +185,8 @@ static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode)
 		 * persistent copy in kernfs_node.
 		 */
 		set_inode_attr(inode, &attrs->ia_iattr);
-		security_inode_notifysecctx(inode, attrs->ia_secdata,
-					    attrs->ia_secdata_len);
+		security_inode_notifysecctx(inode, attrs->ia_context.context,
+					    attrs->ia_context.len);
 	}
 
 	if (kernfs_type(kn) == KERNFS_DIR)
@@ -350,8 +343,6 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler,
 	struct kernfs_node *kn = inode->i_private;
 	struct kernfs_iattrs *attrs;
 	struct lsmcontext context;
-	void *secdata;
-	u32 secdata_len = 0;
 	int error;
 
 	attrs = kernfs_iattrs(kn);
@@ -361,18 +352,17 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler,
 	error = security_inode_setsecurity(inode, suffix, value, size, flags);
 	if (error)
 		return error;
-	error = security_inode_getsecctx(inode, &secdata, &secdata_len);
+	error = security_inode_getsecctx(inode, &context);
 	if (error)
 		return error;
 
 	mutex_lock(&kernfs_mutex);
-	error = kernfs_node_setsecdata(attrs, &secdata, &secdata_len);
+	kernfs_node_setsecdata(attrs, &context);
 	mutex_unlock(&kernfs_mutex);
 
-	if (secdata) {
-		lsmcontext_init(&context, secdata, secdata_len, 0);
+	if (context.context)
 		security_release_secctx(&context);
-	}
+
 	return error;
 }
 
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index 0b7d197a904c..844a028d282f 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -21,8 +21,7 @@
 
 struct kernfs_iattrs {
 	struct iattr		ia_iattr;
-	void			*ia_secdata;
-	u32			ia_secdata_len;
+	struct lsmcontext	ia_context;
 
 	struct simple_xattrs	xattrs;
 };
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index bb3db033e144..1209083565dd 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2304,11 +2304,11 @@ nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types)
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
 static inline __be32
 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
-			    void *context, int len)
+			    struct lsmcontext *context)
 {
 	__be32 *p;
 
-	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
+	p = xdr_reserve_space(xdr, context->len + 4 + 4 + 4);
 	if (!p)
 		return nfserr_resource;
 
@@ -2318,13 +2318,13 @@ nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
 	 */
 	*p++ = cpu_to_be32(0); /* lfs */
 	*p++ = cpu_to_be32(0); /* pi */
-	p = xdr_encode_opaque(p, context, len);
+	p = xdr_encode_opaque(p, context->context, context->len);
 	return 0;
 }
 #else
 static inline __be32
 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
-			    void *context, int len)
+			    struct lsmcontext *context)
 { return 0; }
 #endif
 
@@ -2420,9 +2420,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 	__be32 status;
 	int err;
 	struct nfs4_acl *acl = NULL;
-	struct lsmcontext scaff; /* scaffolding */
-	void *context = NULL;
-	int contextlen;
+	struct lsmcontext context;
 	bool contextsupport = false;
 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
 	u32 minorversion = resp->cstate.minorversion;
@@ -2479,7 +2477,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 	     bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
 		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
 			err = security_inode_getsecctx(d_inode(dentry),
-						&context, &contextlen);
+						       &context);
 		else
 			err = -EOPNOTSUPP;
 		contextsupport = (err == 0);
@@ -2908,8 +2906,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 	}
 
 	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
-		status = nfsd4_encode_security_label(xdr, rqstp, context,
-								contextlen);
+		status = nfsd4_encode_security_label(xdr, rqstp, &context);
 		if (status)
 			goto out;
 	}
@@ -2920,10 +2917,8 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 
 out:
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
-	if (context) {
-		lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/
-		security_release_secctx(&scaff);
-	}
+	if (context.context)
+		security_release_secctx(&context);
 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
 	kfree(acl);
 	if (tempfh) {
diff --git a/include/linux/security.h b/include/linux/security.h
index 2a2785a4e752..bfdb06bc5466 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -485,7 +485,7 @@ void security_release_secctx(struct lsmcontext *cp);
 void security_inode_invalidate_secctx(struct inode *inode);
 int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
 int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
-int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
+int security_inode_getsecctx(struct inode *inode, struct lsmcontext *cp);
 #else /* CONFIG_SECURITY */
 
 static inline int call_lsm_notifier(enum lsm_event event, void *data)
@@ -1286,7 +1286,8 @@ static inline int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32
 {
 	return -EOPNOTSUPP;
 }
-static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
+static inline int security_inode_getsecctx(struct inode *inode,
+					   struct lsmcontext *cp)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/security/security.c b/security/security.c
index 842ac65abc08..b2ffcd1f3057 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2139,9 +2139,18 @@ int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
 }
 EXPORT_SYMBOL(security_inode_setsecctx);
 
-int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
+int security_inode_getsecctx(struct inode *inode, struct lsmcontext *cp)
 {
-	return call_int_hook(inode_getsecctx, -EOPNOTSUPP, inode, ctx, ctxlen);
+	int *display = current->security;
+	struct security_hook_list *hp;
+
+	hlist_for_each_entry(hp, &security_hook_heads.inode_getsecctx, list)
+		if (*display == 0 || *display == hp->slot) {
+			cp->slot = hp->slot;
+			return hp->hook.inode_getsecctx(inode,
+					(void **)&cp->context, &cp->len);
+		}
+	return -EOPNOTSUPP;
 }
 EXPORT_SYMBOL(security_inode_getsecctx);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 20/24] LSM: security_secid_to_secctx in netlink netfilter
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (18 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 19/24] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 22:57   ` Kees Cook
  2019-06-24 21:47   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob Casey Schaufler
                   ` (3 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Change netlink netfilter interfaces to use lsmcontext
pointers, and remove scaffolding.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 net/netfilter/nfnetlink_queue.c | 32 +++++++++++++-------------------
 1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 6da00c7add5b..69efb688383f 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -305,12 +305,10 @@ static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
 	return -1;
 }
 
-static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
+static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context)
 {
-	u32 seclen = 0;
 #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
 	struct lsmblob blob;
-	struct lsmcontext context;
 
 	if (!skb || !sk_fullsock(skb->sk))
 		return 0;
@@ -318,15 +316,16 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
 	read_lock_bh(&skb->sk->sk_callback_lock);
 
 	if (skb->secmark) {
+		/* Any LSM might be looking for the secmark */
 		lsmblob_init(&blob, skb->secmark);
-		security_secid_to_secctx(&blob, &context);
-		*secdata = context.context;
+		security_secid_to_secctx(&blob, context);
 	}
 
 	read_unlock_bh(&skb->sk->sk_callback_lock);
-	seclen = context.len;
+	return context->len;
+#else
+	return 0;
 #endif
-	return seclen;
 }
 
 static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
@@ -402,8 +401,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	enum ip_conntrack_info uninitialized_var(ctinfo);
 	struct nfnl_ct_hook *nfnl_ct;
 	bool csum_verify;
-	struct lsmcontext scaff; /* scaffolding */
-	char *secdata = NULL;
+	struct lsmcontext context;
 	u32 seclen = 0;
 
 	size =    nlmsg_total_size(sizeof(struct nfgenmsg))
@@ -470,7 +468,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	}
 
 	if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
-		seclen = nfqnl_get_sk_secctx(entskb, &secdata);
+		seclen = nfqnl_get_sk_secctx(entskb, &context);
 		if (seclen)
 			size += nla_total_size(seclen);
 	}
@@ -605,7 +603,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	    nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
 		goto nla_put_failure;
 
-	if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
+	if (seclen && nla_put(skb, NFQA_SECCTX, context.len, context.context))
 		goto nla_put_failure;
 
 	if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
@@ -633,10 +631,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	}
 
 	nlh->nlmsg_len = skb->len;
-	if (seclen) {
-		lsmcontext_init(&scaff, secdata, seclen, 0);
-		security_release_secctx(&scaff);
-	}
+	if (seclen)
+		security_release_secctx(&context);
 	return skb;
 
 nla_put_failure:
@@ -644,10 +640,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	kfree_skb(skb);
 	net_err_ratelimited("nf_queue: error creating packet message\n");
 nlmsg_failure:
-	if (seclen) {
-		lsmcontext_init(&scaff, secdata, seclen, 0);
-		security_release_secctx(&scaff);
-	}
+	if (seclen)
+		security_release_secctx(&context);
 	return NULL;
 }
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (19 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 20/24] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 23:12   ` Kees Cook
  2019-06-24 21:33   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 22/24] LSM: Return the lsmblob slot on initialization Casey Schaufler
                   ` (2 subsequent siblings)
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Change the audit code to store full lsmblob data instead of
a single u32 secid. This allows for multiple security modules
to use the audit system at the same time. It also allows the
removal of scaffolding code that was included during the
revision of LSM interfaces.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 kernel/audit.h   |  6 +++---
 kernel/auditsc.c | 38 +++++++++++---------------------------
 2 files changed, 14 insertions(+), 30 deletions(-)

diff --git a/kernel/audit.h b/kernel/audit.h
index 29e29c6f4afb..a8dd479e9556 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -91,7 +91,7 @@ struct audit_names {
 	kuid_t			uid;
 	kgid_t			gid;
 	dev_t			rdev;
-	u32			osid;
+	struct lsmblob		olsm;
 	struct audit_cap_data	fcap;
 	unsigned int		fcap_ver;
 	unsigned char		type;		/* record type */
@@ -148,7 +148,7 @@ struct audit_context {
 	kuid_t		    target_auid;
 	kuid_t		    target_uid;
 	unsigned int	    target_sessionid;
-	struct lsmblob   target_lsm;
+	struct lsmblob	    target_lsm;
 	char		    target_comm[TASK_COMM_LEN];
 
 	struct audit_tree_refs *trees, *first_trees;
@@ -165,7 +165,7 @@ struct audit_context {
 			kuid_t			uid;
 			kgid_t			gid;
 			umode_t			mode;
-			u32			osid;
+			struct lsmblob		olsm;
 			int			has_perm;
 			uid_t			perm_uid;
 			gid_t			perm_gid;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 0478680cd0a8..d3ad13f11788 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -646,17 +646,15 @@ static int audit_filter_rules(struct task_struct *tsk,
 			if (f->lsm_rule) {
 				/* Find files that match */
 				if (name) {
-					lsmblob_init(&blob, name->osid);
 					result = security_audit_rule_match(
-								&blob,
+								&name->olsm,
 								f->type,
 								f->op,
 								f->lsm_rule);
 				} else if (ctx) {
 					list_for_each_entry(n, &ctx->names_list, list) {
-						lsmblob_init(&blob, n->osid);
 						if (security_audit_rule_match(
-								&blob,
+								&n->olsm,
 								f->type,
 								f->op,
 								f->lsm_rule)) {
@@ -668,8 +666,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 				/* Find ipc objects that match */
 				if (!ctx || ctx->type != AUDIT_IPC)
 					break;
-				lsmblob_init(&blob, ctx->ipc.osid);
-				if (security_audit_rule_match(&blob,
+				if (security_audit_rule_match(&ctx->ipc.olsm,
 							      f->type, f->op,
 							      f->lsm_rule))
 					++result;
@@ -1187,21 +1184,18 @@ static void show_special(struct audit_context *context, int *call_panic)
 				context->socketcall.args[i]);
 		break; }
 	case AUDIT_IPC: {
-		u32 osid = context->ipc.osid;
+		struct lsmblob *olsm = &context->ipc.olsm;
 
 		audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
 				 from_kuid(&init_user_ns, context->ipc.uid),
 				 from_kgid(&init_user_ns, context->ipc.gid),
 				 context->ipc.mode);
-		if (osid) {
+		if (lsmblob_is_set(olsm)) {
 			struct lsmcontext lsmcxt;
-			struct lsmblob blob;
 
-			lsmblob_init(&blob, osid);
-			if (security_secid_to_secctx(&blob, &lsmcxt)) {
-				audit_log_format(ab, " osid=%u", osid);
+			if (security_secid_to_secctx(olsm, &lsmcxt))
 				*call_panic = 1;
-			} else {
+			else {
 				audit_log_format(ab, " obj=%s", lsmcxt.context);
 				security_release_secctx(&lsmcxt);
 			}
@@ -1346,13 +1340,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 				 from_kgid(&init_user_ns, n->gid),
 				 MAJOR(n->rdev),
 				 MINOR(n->rdev));
-	if (n->osid != 0) {
-		struct lsmblob blob;
+	if (lsmblob_is_set(&n->olsm)) {
 		struct lsmcontext lsmctx;
 
-		lsmblob_init(&blob, n->osid);
-		if (security_secid_to_secctx(&blob, &lsmctx)) {
-			audit_log_format(ab, " osid=%u", n->osid);
+		if (security_secid_to_secctx(&n->olsm, &lsmctx)) {
 			if (call_panic)
 				*call_panic = 2;
 		} else {
@@ -1906,17 +1897,13 @@ static inline int audit_copy_fcaps(struct audit_names *name,
 void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
 		      struct inode *inode, unsigned int flags)
 {
-	struct lsmblob blob;
-
 	name->ino   = inode->i_ino;
 	name->dev   = inode->i_sb->s_dev;
 	name->mode  = inode->i_mode;
 	name->uid   = inode->i_uid;
 	name->gid   = inode->i_gid;
 	name->rdev  = inode->i_rdev;
-	security_inode_getsecid(inode, &blob);
-	/* scaffolding until osid is updated */
-	name->osid = blob.secid[0];
+	security_inode_getsecid(inode, &name->olsm);
 	if (flags & AUDIT_INODE_NOEVAL) {
 		name->fcap_ver = -1;
 		return;
@@ -2266,14 +2253,11 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
 {
 	struct audit_context *context = audit_context();
-	struct lsmblob blob;
 	context->ipc.uid = ipcp->uid;
 	context->ipc.gid = ipcp->gid;
 	context->ipc.mode = ipcp->mode;
 	context->ipc.has_perm = 0;
-	security_ipc_getsecid(ipcp, &blob);
-	/* scaffolding on the [0] - change "osid" to a lsmblob */
-	context->ipc.osid = blob.secid[0];
+	security_ipc_getsecid(ipcp, &context->ipc.olsm);
 	context->type = AUDIT_IPC;
 }
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 22/24] LSM: Return the lsmblob slot on initialization
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (20 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 23:13   ` Kees Cook
  2019-06-24 21:47   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 23/24] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
  2019-06-21 18:52 ` [PATCH v3 24/24] AppArmor: Remove the exclusive flag Casey Schaufler
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Return the slot allocated to the calling LSM in the lsmblob
structure. This can be used to set lsmblobs explicitly for
netlabel interfaces.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h  | 4 ++--
 security/apparmor/lsm.c    | 8 ++++++--
 security/security.c        | 9 +++++++--
 security/selinux/hooks.c   | 5 ++++-
 security/smack/smack_lsm.c | 5 ++++-
 5 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 4d1ddf1a2aa6..ce341bcbce5d 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2068,8 +2068,8 @@ struct lsm_blob_sizes {
 extern struct security_hook_heads security_hook_heads;
 extern char *lsm_names;
 
-extern void security_add_hooks(struct security_hook_list *hooks, int count,
-				char *lsm);
+extern int security_add_hooks(struct security_hook_list *hooks, int count,
+			      char *lsm);
 
 #define LSM_FLAG_LEGACY_MAJOR	BIT(0)
 #define LSM_FLAG_EXCLUSIVE	BIT(1)
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 2716e7731279..dcbbefbd95ff 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -47,6 +47,9 @@
 /* Flag indicating whether initialization completed */
 int apparmor_initialized;
 
+/* Slot for the AppArmor secid in the lsmblob structure */
+int apparmor_lsmblob_slot;
+
 DEFINE_PER_CPU(struct aa_buffers, aa_buffers);
 
 
@@ -1678,8 +1681,9 @@ static int __init apparmor_init(void)
 		aa_free_root_ns();
 		goto buffers_out;
 	}
-	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
-				"apparmor");
+	apparmor_lsmblob_slot = security_add_hooks(apparmor_hooks,
+						   ARRAY_SIZE(apparmor_hooks),
+						   "apparmor");
 
 	/* Report that AppArmor successfully initialized */
 	apparmor_initialized = 1;
diff --git a/security/security.c b/security/security.c
index b2ffcd1f3057..c93a368b697b 100644
--- a/security/security.c
+++ b/security/security.c
@@ -437,9 +437,12 @@ static int lsm_slot __initdata;
  * Each LSM has to register its hooks with the infrastructure.
  * If the LSM is using hooks that export secids allocate a slot
  * for it in the lsmblob.
+ *
+ * Returns the slot number in the lsmblob structure if one is
+ * allocated or LSMBLOB_INVALID if one was not allocated.
  */
-void __init security_add_hooks(struct security_hook_list *hooks, int count,
-				char *lsm)
+int __init security_add_hooks(struct security_hook_list *hooks, int count,
+			      char *lsm)
 {
 	int slot = LSMBLOB_INVALID;
 	int i;
@@ -479,6 +482,8 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
 	}
 	if (lsm_append(lsm, &lsm_names) < 0)
 		panic("%s - Cannot get early memory.\n", __func__);
+
+	return slot;
 }
 
 int call_lsm_notifier(enum lsm_event event, void *data)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ee840fecfebb..1e09acbf9630 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -103,6 +103,7 @@
 #include "avc_ss.h"
 
 struct selinux_state selinux_state;
+int selinux_lsmblob_slot;
 
 /* SECMARK reference count */
 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
@@ -6877,7 +6878,9 @@ static __init int selinux_init(void)
 
 	hashtab_cache_init();
 
-	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
+	selinux_lsmblob_slot = security_add_hooks(selinux_hooks,
+						  ARRAY_SIZE(selinux_hooks),
+						  "selinux");
 
 	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
 		panic("SELinux: Unable to register AVC netcache callback\n");
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 3834b751d1e9..273f311fb153 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -60,6 +60,7 @@ static LIST_HEAD(smk_ipv6_port_list);
 #endif
 static struct kmem_cache *smack_inode_cache;
 int smack_enabled;
+int smack_lsmblob_slot;
 
 #define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
 static struct {
@@ -4749,7 +4750,9 @@ static __init int smack_init(void)
 	/*
 	 * Register with LSM
 	 */
-	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
+	smack_lsmblob_slot = security_add_hooks(smack_hooks,
+						ARRAY_SIZE(smack_hooks),
+						"smack");
 	smack_enabled = 1;
 
 	pr_info("Smack:  Initializing.\n");
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 23/24] NET: Store LSM netlabel data in a lsmblob
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (21 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 22/24] LSM: Return the lsmblob slot on initialization Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 23:15   ` Kees Cook
  2019-06-24 21:44   ` John Johansen
  2019-06-21 18:52 ` [PATCH v3 24/24] AppArmor: Remove the exclusive flag Casey Schaufler
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Netlabel uses LSM interfaces requiring an lsmblob and
the internal storage is used to pass information between
these interfaces, so change the internal data from a secid
to a lsmblob. Update the netlabel interfaces and their
callers to accomodate the change.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/net/netlabel.h              |  8 ++--
 net/ipv4/cipso_ipv4.c               |  6 ++-
 net/netlabel/netlabel_kapi.c        |  6 +--
 net/netlabel/netlabel_unlabeled.c   | 57 +++++++++++------------------
 net/netlabel/netlabel_unlabeled.h   |  2 +-
 security/selinux/include/security.h |  1 +
 security/selinux/netlabel.c         |  2 +-
 security/selinux/ss/services.c      |  4 +-
 security/smack/smack.h              |  1 +
 security/smack/smack_lsm.c          |  3 +-
 security/smack/smackfs.c            | 10 +++--
 11 files changed, 48 insertions(+), 52 deletions(-)

diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 72d6435fc16c..6c550455e69f 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -180,7 +180,7 @@ struct netlbl_lsm_catmap {
  * @attr.mls: MLS sensitivity label
  * @attr.mls.cat: MLS category bitmap
  * @attr.mls.lvl: MLS sensitivity level
- * @attr.secid: LSM specific secid token
+ * @attr.lsmblob: LSM specific data
  *
  * Description:
  * This structure is used to pass security attributes between NetLabel and the
@@ -215,7 +215,7 @@ struct netlbl_lsm_secattr {
 			struct netlbl_lsm_catmap *cat;
 			u32 lvl;
 		} mls;
-		u32 secid;
+		struct lsmblob lsmblob;
 	} attr;
 };
 
@@ -429,7 +429,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
 				const void *addr,
 				const void *mask,
 				u16 family,
-				u32 secid,
+				struct lsmblob *lsmblob,
 				struct netlbl_audit *audit_info);
 int netlbl_cfg_unlbl_static_del(struct net *net,
 				const char *dev_name,
@@ -537,7 +537,7 @@ static inline int netlbl_cfg_unlbl_static_add(struct net *net,
 					      const void *addr,
 					      const void *mask,
 					      u16 family,
-					      u32 secid,
+					      struct lsmblob *lsmblob,
 					      struct netlbl_audit *audit_info)
 {
 	return -ENOSYS;
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index f0165c5f376b..eb4939f38a14 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1481,7 +1481,8 @@ static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
 
 	buffer[0] = CIPSO_V4_TAG_LOCAL;
 	buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
-	*(u32 *)&buffer[2] = secattr->attr.secid;
+	/* only one netlabel user - the first */
+	*(u32 *)&buffer[2] = secattr->attr.lsmblob.secid[0];
 
 	return CIPSO_V4_TAG_LOC_BLEN;
 }
@@ -1501,7 +1502,8 @@ static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
 				 const unsigned char *tag,
 				 struct netlbl_lsm_secattr *secattr)
 {
-	secattr->attr.secid = *(u32 *)&tag[2];
+	/* only one netlabel user - the first */
+	secattr->attr.lsmblob.secid[0] = *(u32 *)&tag[2];
 	secattr->flags |= NETLBL_SECATTR_SECID;
 
 	return 0;
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index ee3e5b6471a6..724d44943543 100644
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -210,7 +210,7 @@ int netlbl_cfg_unlbl_map_add(const char *domain,
  * @addr: IP address in network byte order (struct in[6]_addr)
  * @mask: address mask in network byte order (struct in[6]_addr)
  * @family: address family
- * @secid: LSM secid value for the entry
+ * @lsmblob: LSM data value for the entry
  * @audit_info: NetLabel audit information
  *
  * Description:
@@ -224,7 +224,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
 				const void *addr,
 				const void *mask,
 				u16 family,
-				u32 secid,
+				struct lsmblob *lsmblob,
 				struct netlbl_audit *audit_info)
 {
 	u32 addr_len;
@@ -244,7 +244,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
 
 	return netlbl_unlhsh_add(net,
 				 dev_name, addr, mask, addr_len,
-				 secid, audit_info);
+				 lsmblob, audit_info);
 }
 
 /**
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 4716e0011ba5..57ede7781c8f 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -80,7 +80,7 @@ struct netlbl_unlhsh_tbl {
 #define netlbl_unlhsh_addr4_entry(iter) \
 	container_of(iter, struct netlbl_unlhsh_addr4, list)
 struct netlbl_unlhsh_addr4 {
-	u32 secid;
+	struct lsmblob lsmblob;
 
 	struct netlbl_af4list list;
 	struct rcu_head rcu;
@@ -88,7 +88,7 @@ struct netlbl_unlhsh_addr4 {
 #define netlbl_unlhsh_addr6_entry(iter) \
 	container_of(iter, struct netlbl_unlhsh_addr6, list)
 struct netlbl_unlhsh_addr6 {
-	u32 secid;
+	struct lsmblob lsmblob;
 
 	struct netlbl_af6list list;
 	struct rcu_head rcu;
@@ -233,7 +233,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
  * @iface: the associated interface entry
  * @addr: IPv4 address in network byte order
  * @mask: IPv4 address mask in network byte order
- * @secid: LSM secid value for entry
+ * @lsmblob: LSM data value for entry
  *
  * Description:
  * Add a new address entry into the unlabeled connection hash table using the
@@ -244,7 +244,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
 static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
 				   const struct in_addr *addr,
 				   const struct in_addr *mask,
-				   u32 secid)
+				   struct lsmblob *lsmblob)
 {
 	int ret_val;
 	struct netlbl_unlhsh_addr4 *entry;
@@ -256,7 +256,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
 	entry->list.addr = addr->s_addr & mask->s_addr;
 	entry->list.mask = mask->s_addr;
 	entry->list.valid = 1;
-	entry->secid = secid;
+	entry->lsmblob = *lsmblob;
 
 	spin_lock(&netlbl_unlhsh_lock);
 	ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);
@@ -273,7 +273,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
  * @iface: the associated interface entry
  * @addr: IPv6 address in network byte order
  * @mask: IPv6 address mask in network byte order
- * @secid: LSM secid value for entry
+ * @lsmblob: LSM data value for entry
  *
  * Description:
  * Add a new address entry into the unlabeled connection hash table using the
@@ -284,7 +284,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
 static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
 				   const struct in6_addr *addr,
 				   const struct in6_addr *mask,
-				   u32 secid)
+				   struct lsmblob *lsmblob)
 {
 	int ret_val;
 	struct netlbl_unlhsh_addr6 *entry;
@@ -300,7 +300,7 @@ static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
 	entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
 	entry->list.mask = *mask;
 	entry->list.valid = 1;
-	entry->secid = secid;
+	entry->lsmblob = *lsmblob;
 
 	spin_lock(&netlbl_unlhsh_lock);
 	ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);
@@ -379,7 +379,7 @@ int netlbl_unlhsh_add(struct net *net,
 		      const void *addr,
 		      const void *mask,
 		      u32 addr_len,
-		      u32 secid,
+		      struct lsmblob *lsmblob,
 		      struct netlbl_audit *audit_info)
 {
 	int ret_val;
@@ -388,7 +388,6 @@ int netlbl_unlhsh_add(struct net *net,
 	struct netlbl_unlhsh_iface *iface;
 	struct audit_buffer *audit_buf = NULL;
 	struct lsmcontext context;
-	struct lsmblob blob;
 
 	if (addr_len != sizeof(struct in_addr) &&
 	    addr_len != sizeof(struct in6_addr))
@@ -421,7 +420,7 @@ int netlbl_unlhsh_add(struct net *net,
 		const struct in_addr *addr4 = addr;
 		const struct in_addr *mask4 = mask;
 
-		ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
+		ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, lsmblob);
 		if (audit_buf != NULL)
 			netlbl_af4list_audit_addr(audit_buf, 1,
 						  dev_name,
@@ -434,7 +433,7 @@ int netlbl_unlhsh_add(struct net *net,
 		const struct in6_addr *addr6 = addr;
 		const struct in6_addr *mask6 = mask;
 
-		ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
+		ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, lsmblob);
 		if (audit_buf != NULL)
 			netlbl_af6list_audit_addr(audit_buf, 1,
 						  dev_name,
@@ -451,8 +450,7 @@ int netlbl_unlhsh_add(struct net *net,
 unlhsh_add_return:
 	rcu_read_unlock();
 	if (audit_buf != NULL) {
-		lsmblob_init(&blob, secid);
-		if (security_secid_to_secctx(&blob, &context) == 0) {
+		if (security_secid_to_secctx(lsmblob, &context) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s",
 					 context.context);
 			security_release_secctx(&context);
@@ -487,7 +485,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 	struct audit_buffer *audit_buf;
 	struct net_device *dev;
 	struct lsmcontext context;
-	struct lsmblob blob;
 
 	spin_lock(&netlbl_unlhsh_lock);
 	list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
@@ -507,10 +504,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 					  addr->s_addr, mask->s_addr);
 		if (dev != NULL)
 			dev_put(dev);
-		if (entry != NULL)
-			lsmblob_init(&blob, entry->secid);
 		if (entry != NULL &&
-		    security_secid_to_secctx(&blob, &context) == 0) {
+		    security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s",
 					 context.context);
 			security_release_secctx(&context);
@@ -551,7 +546,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 	struct audit_buffer *audit_buf;
 	struct net_device *dev;
 	struct lsmcontext context;
-	struct lsmblob blob;
 
 	spin_lock(&netlbl_unlhsh_lock);
 	list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
@@ -570,10 +564,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 					  addr, mask);
 		if (dev != NULL)
 			dev_put(dev);
-		if (entry != NULL)
-			lsmblob_init(&blob, entry->secid);
 		if (entry != NULL &&
-		    security_secid_to_secctx(&blob, &context) == 0) {
+		    security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s",
 					 context.context);
 			security_release_secctx(&context);
@@ -927,9 +919,8 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
 	if (ret_val != 0)
 		return ret_val;
 
-	/* scaffolding with the [0] */
 	return netlbl_unlhsh_add(&init_net,
-				 dev_name, addr, mask, addr_len, blob.secid[0],
+				 dev_name, addr, mask, addr_len, &blob,
 				 &audit_info);
 }
 
@@ -977,10 +968,8 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
 	if (ret_val != 0)
 		return ret_val;
 
-	/* scaffolding with the [0] */
 	return netlbl_unlhsh_add(&init_net,
-				 NULL, addr, mask, addr_len, blob.secid[0],
-				 &audit_info);
+				 NULL, addr, mask, addr_len, &blob, &audit_info);
 }
 
 /**
@@ -1092,8 +1081,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 	struct net_device *dev;
 	struct lsmcontext context;
 	void *data;
-	u32 secid;
-	struct lsmblob blob;
+	struct lsmblob *lsmb;
 
 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
 			   cb_arg->seq, &netlbl_unlabel_gnl_family,
@@ -1131,7 +1119,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 		if (ret_val != 0)
 			goto list_cb_failure;
 
-		secid = addr4->secid;
+		lsmb = (struct lsmblob *)&addr4->lsmblob;
 	} else {
 		ret_val = nla_put_in6_addr(cb_arg->skb,
 					   NLBL_UNLABEL_A_IPV6ADDR,
@@ -1145,11 +1133,10 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 		if (ret_val != 0)
 			goto list_cb_failure;
 
-		secid = addr6->secid;
+		lsmb = (struct lsmblob *)&addr6->lsmblob;
 	}
 
-	lsmblob_init(&blob, secid);
-	ret_val = security_secid_to_secctx(&blob, &context);
+	ret_val = security_secid_to_secctx(lsmb, &context);
 	if (ret_val != 0)
 		goto list_cb_failure;
 	ret_val = nla_put(cb_arg->skb,
@@ -1500,7 +1487,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
 					      &iface->addr4_list);
 		if (addr4 == NULL)
 			goto unlabel_getattr_nolabel;
-		secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;
+		secattr->attr.lsmblob = netlbl_unlhsh_addr4_entry(addr4)->lsmblob;
 		break;
 	}
 #if IS_ENABLED(CONFIG_IPV6)
@@ -1513,7 +1500,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
 					      &iface->addr6_list);
 		if (addr6 == NULL)
 			goto unlabel_getattr_nolabel;
-		secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;
+		secattr->attr.lsmblob = netlbl_unlhsh_addr6_entry(addr6)->lsmblob;
 		break;
 	}
 #endif /* IPv6 */
diff --git a/net/netlabel/netlabel_unlabeled.h b/net/netlabel/netlabel_unlabeled.h
index 3a9e5dc9511b..dcff99695c97 100644
--- a/net/netlabel/netlabel_unlabeled.h
+++ b/net/netlabel/netlabel_unlabeled.h
@@ -225,7 +225,7 @@ int netlbl_unlhsh_add(struct net *net,
 		      const void *addr,
 		      const void *mask,
 		      u32 addr_len,
-		      u32 secid,
+		      struct lsmblob *lsmblob,
 		      struct netlbl_audit *audit_info);
 int netlbl_unlhsh_remove(struct net *net,
 			 const char *dev_name,
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index b5b7c5aade8c..94787988c8fb 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -68,6 +68,7 @@
 struct netlbl_lsm_secattr;
 
 extern int selinux_enabled;
+extern int selinux_lsmblob_slot;
 
 /* Policy capabilities */
 enum {
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index c40914a157b7..320a4cdc657e 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -122,7 +122,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
 		return NULL;
 
 	if ((secattr->flags & NETLBL_SECATTR_SECID) &&
-	    (secattr->attr.secid == sid))
+	    (secattr->attr.lsmblob.secid[selinux_lsmblob_slot] == sid))
 		return secattr;
 
 	return NULL;
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index e3f5d6aece66..a3be1afafd7f 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -3593,7 +3593,7 @@ int security_netlbl_secattr_to_sid(struct selinux_state *state,
 	if (secattr->flags & NETLBL_SECATTR_CACHE)
 		*sid = *(u32 *)secattr->cache->data;
 	else if (secattr->flags & NETLBL_SECATTR_SECID)
-		*sid = secattr->attr.secid;
+		*sid = secattr->attr.lsmblob.secid[selinux_lsmblob_slot];
 	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
 		rc = -EIDRM;
 		ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
@@ -3666,7 +3666,7 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state,
 	if (secattr->domain == NULL)
 		goto out;
 
-	secattr->attr.secid = sid;
+	secattr->attr.lsmblob.secid[selinux_lsmblob_slot] = sid;
 	secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
 	mls_export_netlbl_lvl(policydb, ctx, secattr);
 	rc = mls_export_netlbl_cat(policydb, ctx, secattr);
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 7cc3a3382fee..097ffde7f202 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -320,6 +320,7 @@ void smk_destroy_label_list(struct list_head *list);
  * Shared data.
  */
 extern int smack_enabled;
+extern int smack_lsmblob_slot;
 extern int smack_cipso_direct;
 extern int smack_cipso_mapped;
 extern struct smack_known *smack_net_ambient;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 273f311fb153..b83aba0f2013 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3742,7 +3742,8 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
 		/*
 		 * Looks like a fallback, which gives us a secid.
 		 */
-		return smack_from_secid(sap->attr.secid);
+		return smack_from_secid(
+				sap->attr.lsmblob.secid[smack_lsmblob_slot]);
 	/*
 	 * Without guidance regarding the smack value
 	 * for the packet fall back on the network
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index faf2ea3968b3..066d53c29ed4 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -1150,6 +1150,7 @@ static void smk_net4addr_insert(struct smk_net4addr *new)
 static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
 				size_t count, loff_t *ppos)
 {
+	struct lsmblob lsmblob;
 	struct smk_net4addr *snp;
 	struct sockaddr_in newname;
 	char *smack;
@@ -1281,10 +1282,13 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
 	 * this host so that incoming packets get labeled.
 	 * but only if we didn't get the special CIPSO option
 	 */
-	if (rc == 0 && skp != NULL)
+	if (rc == 0 && skp != NULL) {
+		lsmblob_init(&lsmblob, 0);
+		lsmblob.secid[smack_lsmblob_slot] = snp->smk_label->smk_secid;
 		rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
-			&snp->smk_host, &snp->smk_mask, PF_INET,
-			snp->smk_label->smk_secid, &audit_info);
+			&snp->smk_host, &snp->smk_mask, PF_INET, &lsmblob,
+			&audit_info);
+	}
 
 	if (rc == 0)
 		rc = count;
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* [PATCH v3 24/24] AppArmor: Remove the exclusive flag
  2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
                   ` (22 preceding siblings ...)
  2019-06-21 18:52 ` [PATCH v3 23/24] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
@ 2019-06-21 18:52 ` Casey Schaufler
  2019-06-22 23:15   ` Kees Cook
  2019-06-24 21:45   ` John Johansen
  23 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-21 18:52 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

With the inclusion of the "display" process attribute
mechanism AppArmor no longer needs to be treated as an
"exclusive" security module. Remove the flag that indicates
it is exclusive. Remove the stub getpeersec_dgram AppArmor
hook as it has no effect in the single LSM case and
interferes in the multiple LSM case.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 security/apparmor/lsm.c | 20 +-------------------
 1 file changed, 1 insertion(+), 19 deletions(-)

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index dcbbefbd95ff..c4365434f10b 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1082,22 +1082,6 @@ static int apparmor_socket_getpeersec_stream(struct socket *sock,
 	return error;
 }
 
-/**
- * apparmor_socket_getpeersec_dgram - get security label of packet
- * @sock: the peer socket
- * @skb: packet data
- * @secid: pointer to where to put the secid of the packet
- *
- * Sets the netlabel socket state on sk from parent
- */
-static int apparmor_socket_getpeersec_dgram(struct socket *sock,
-					    struct sk_buff *skb, u32 *secid)
-
-{
-	/* TODO: requires secid support */
-	return -ENOPROTOOPT;
-}
-
 /**
  * apparmor_sock_graft - Initialize newly created socket
  * @sk: child sock
@@ -1196,8 +1180,6 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
 #endif
 	LSM_HOOK_INIT(socket_getpeersec_stream,
 		      apparmor_socket_getpeersec_stream),
-	LSM_HOOK_INIT(socket_getpeersec_dgram,
-		      apparmor_socket_getpeersec_dgram),
 	LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
 #ifdef CONFIG_NETWORK_SECMARK
 	LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
@@ -1709,7 +1691,7 @@ static int __init apparmor_init(void)
 
 DEFINE_LSM(apparmor) = {
 	.name = "apparmor",
-	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
+	.flags = LSM_FLAG_LEGACY_MAJOR,
 	.enabled = &apparmor_enabled,
 	.blobs = &apparmor_blob_sizes,
 	.init = apparmor_init,
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 04/24] LSM: Create and manage the lsmblob data structure.
  2019-06-21 18:52 ` [PATCH v3 04/24] LSM: Create and manage the lsmblob data structure Casey Schaufler
@ 2019-06-22 22:42   ` Kees Cook
  2019-06-24 18:38   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:42 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:13AM -0700, Casey Schaufler wrote:
> When more than one security module is exporting data to
> audit and networking sub-systems a single 32 bit integer
> is no longer sufficient to represent the data. Add a
> structure to be used instead.
> 
> The lsmblob structure is currently an array of
> u32 "secids". There is an entry for each of the
> security modules built into the system that would
> use secids if active. The system assigns the module
> a "slot" when it registers hooks. If modules are
> compiled in but not registered there will be unused
> slots.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Acked-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  include/linux/lsm_hooks.h |  1 +
>  include/linux/security.h  | 62 +++++++++++++++++++++++++++++++++++++++
>  security/security.c       | 36 +++++++++++++++++++++++
>  3 files changed, 99 insertions(+)
> 
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index 3fe39abccc8f..4d1ddf1a2aa6 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -2038,6 +2038,7 @@ struct security_hook_list {
>  	struct hlist_head		*head;
>  	union security_list_options	hook;
>  	char				*lsm;
> +	int				slot;
>  } __randomize_layout;
>  
>  /*
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 49f2685324b0..0aa9417a5762 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -76,6 +76,68 @@ enum lsm_event {
>  	LSM_POLICY_CHANGE,
>  };
>  
> +/*
> + * Data exported by the security modules
> + */
> +#define LSMBLOB_ENTRIES ( \
> +	(IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \
> +	(IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \
> +	(IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0))
> +
> +struct lsmblob {
> +	u32     secid[LSMBLOB_ENTRIES];
> +};
> +
> +#define LSMBLOB_INVALID	-1
> +
> +/**
> + * lsmblob_init - initialize an lsmblob structure.
> + * @blob: Pointer to the data to initialize
> + * @secid: The initial secid value
> + *
> + * Set all secid for all modules to the specified value.
> + */
> +static inline void lsmblob_init(struct lsmblob *blob, u32 secid)
> +{
> +	int i;
> +
> +	for (i = 0; i < LSMBLOB_ENTRIES; i++)
> +		blob->secid[i] = secid;
> +}
> +
> +/**
> + * lsmblob_is_set - report if there is an value in the lsmblob
> + * @blob: Pointer to the exported LSM data
> + *
> + * Returns true if there is a secid set, false otherwise
> + */
> +static inline bool lsmblob_is_set(struct lsmblob *blob)
> +{
> +	int i;
> +
> +	for (i = 0; i < LSMBLOB_ENTRIES; i++)
> +		if (blob->secid[i] != 0)
> +			return true;
> +	return false;
> +}
> +
> +/**
> + * lsmblob_equal - report if the two lsmblob's are equal
> + * @bloba: Pointer to one LSM data
> + * @blobb: Pointer to the other LSM data
> + *
> + * Returns true if all entries in the two are equal, false otherwise
> + */
> +static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)
> +{
> +	int i;
> +
> +	for (i = 0; i < LSMBLOB_ENTRIES; i++)
> +		if (bloba->secid[i] != blobb->secid[i])
> +			return false;
> +	return true;
> +}
> +
>  /* These functions are in security/commoncap.c */
>  extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
>  		       int cap, unsigned int opts);
> diff --git a/security/security.c b/security/security.c
> index d05f00a40e82..7618c761060d 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -317,6 +317,7 @@ static void __init ordered_lsm_init(void)
>  	init_debug("sock blob size       = %d\n", blob_sizes.lbs_sock);
>  	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
>  	init_debug("task blob size       = %d\n", blob_sizes.lbs_task);
> +	init_debug("lsmblob size         = %lu\n", sizeof(struct lsmblob));
>  
>  	/*
>  	 * Create any kmem_caches needed for blobs
> @@ -420,6 +421,11 @@ static int lsm_append(char *new, char **result)
>  	return 0;
>  }
>  
> +/*
> + * Current index to use while initializing the lsmblob secid list.
> + */
> +static int lsm_slot __initdata;
> +
>  /**
>   * security_add_hooks - Add a modules hooks to the hook lists.
>   * @hooks: the hooks to add
> @@ -427,15 +433,45 @@ static int lsm_append(char *new, char **result)
>   * @lsm: the name of the security module
>   *
>   * Each LSM has to register its hooks with the infrastructure.
> + * If the LSM is using hooks that export secids allocate a slot
> + * for it in the lsmblob.
>   */
>  void __init security_add_hooks(struct security_hook_list *hooks, int count,
>  				char *lsm)
>  {
> +	int slot = LSMBLOB_INVALID;
>  	int i;
>  
>  	for (i = 0; i < count; i++) {
>  		hooks[i].lsm = lsm;
>  		hlist_add_tail_rcu(&hooks[i].list, hooks[i].head);
> +		/*
> +		 * If this is one of the hooks that uses a secid
> +		 * note it so that a slot can in allocated for the
> +		 * secid in the lsmblob structure.
> +		 */
> +		if (hooks[i].head == &security_hook_heads.audit_rule_match ||
> +		    hooks[i].head == &security_hook_heads.kernel_act_as ||
> +		    hooks[i].head ==
> +			&security_hook_heads.socket_getpeersec_dgram ||
> +		    hooks[i].head == &security_hook_heads.getprocattr ||
> +		    hooks[i].head == &security_hook_heads.setprocattr ||
> +		    hooks[i].head == &security_hook_heads.secctx_to_secid ||
> +		    hooks[i].head == &security_hook_heads.secid_to_secctx ||
> +		    hooks[i].head == &security_hook_heads.ipc_getsecid ||
> +		    hooks[i].head == &security_hook_heads.task_getsecid ||
> +		    hooks[i].head == &security_hook_heads.inode_getsecid ||
> +		    hooks[i].head == &security_hook_heads.cred_getsecid) {
> +			if (slot == LSMBLOB_INVALID) {
> +				slot = lsm_slot++;
> +				if (slot >= LSMBLOB_ENTRIES)
> +					panic("%s Too many LSMs registered.\n",
> +					      __func__);
> +				init_debug("%s assigned lsmblob slot %d\n",
> +					hooks[i].lsm, slot);
> +			}
> +		}
> +		hooks[i].slot = slot;
>  	}
>  	if (lsm_append(lsm, &lsm_names) < 0)
>  		panic("%s - Cannot get early memory.\n", __func__);
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 05/24] Use lsmblob in security_audit_rule_match
  2019-06-21 18:52 ` [PATCH v3 05/24] Use lsmblob in security_audit_rule_match Casey Schaufler
@ 2019-06-22 22:43   ` Kees Cook
  2019-06-24 18:39   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:43 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:14AM -0700, Casey Schaufler wrote:
> Change the secid parameter of security_audit_rule_match
> to a lsmblob structure pointer. Pass the entry from the
> lsmblob structure for the approprite slot to the LSM hook.
> 
> Change the users of security_audit_rule_match to use the
> lsmblob instead of a u32. In some cases this requires a
> temporary conversion using lsmblob_init() that will go
> away when other interfaces get converted.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  include/linux/security.h            |  7 ++++---
>  kernel/auditfilter.c                |  4 +++-
>  kernel/auditsc.c                    | 14 ++++++++++----
>  security/integrity/ima/ima.h        |  4 ++--
>  security/integrity/ima/ima_policy.c |  7 +++++--
>  security/security.c                 | 14 ++++++++++++--
>  6 files changed, 36 insertions(+), 14 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 0aa9417a5762..52d89c4a9594 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -1757,7 +1757,8 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer)
>  #ifdef CONFIG_SECURITY
>  int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule);
>  int security_audit_rule_known(struct audit_krule *krule);
> -int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule);
> +int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
> +			      void *lsmrule);
>  void security_audit_rule_free(void *lsmrule);
>  
>  #else
> @@ -1773,8 +1774,8 @@ static inline int security_audit_rule_known(struct audit_krule *krule)
>  	return 0;
>  }
>  
> -static inline int security_audit_rule_match(u32 secid, u32 field, u32 op,
> -					    void *lsmrule)
> +static inline int security_audit_rule_match(struct lsmblob *blob, u32 field,
> +					    u32 op, void *lsmrule)
>  {
>  	return 0;
>  }
> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> index 63f8b3f26fab..da211065160f 100644
> --- a/kernel/auditfilter.c
> +++ b/kernel/auditfilter.c
> @@ -1324,6 +1324,7 @@ int audit_filter(int msgtype, unsigned int listtype)
>  			struct audit_field *f = &e->rule.fields[i];
>  			pid_t pid;
>  			u32 sid;
> +			struct lsmblob blob;
>  
>  			switch (f->type) {
>  			case AUDIT_PID:
> @@ -1354,7 +1355,8 @@ int audit_filter(int msgtype, unsigned int listtype)
>  			case AUDIT_SUBJ_CLR:
>  				if (f->lsm_rule) {
>  					security_task_getsecid(current, &sid);
> -					result = security_audit_rule_match(sid,
> +					lsmblob_init(&blob, sid);
> +					result = security_audit_rule_match(&blob,
>  						   f->type, f->op, f->lsm_rule);
>  				}
>  				break;
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index d1eab1d4a930..18ee5556c086 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -445,6 +445,7 @@ static int audit_filter_rules(struct task_struct *tsk,
>  	const struct cred *cred;
>  	int i, need_sid = 1;
>  	u32 sid;
> +	struct lsmblob blob;
>  	unsigned int sessionid;
>  
>  	cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
> @@ -630,7 +631,9 @@ static int audit_filter_rules(struct task_struct *tsk,
>  					security_task_getsecid(tsk, &sid);
>  					need_sid = 0;
>  				}
> -				result = security_audit_rule_match(sid, f->type,
> +				lsmblob_init(&blob, sid);
> +				result = security_audit_rule_match(&blob,
> +								   f->type,
>  								   f->op,
>  								   f->lsm_rule);
>  			}
> @@ -645,15 +648,17 @@ static int audit_filter_rules(struct task_struct *tsk,
>  			if (f->lsm_rule) {
>  				/* Find files that match */
>  				if (name) {
> +					lsmblob_init(&blob, name->osid);
>  					result = security_audit_rule_match(
> -								name->osid,
> +								&blob,
>  								f->type,
>  								f->op,
>  								f->lsm_rule);
>  				} else if (ctx) {
>  					list_for_each_entry(n, &ctx->names_list, list) {
> +						lsmblob_init(&blob, n->osid);
>  						if (security_audit_rule_match(
> -								n->osid,
> +								&blob,
>  								f->type,
>  								f->op,
>  								f->lsm_rule)) {
> @@ -665,7 +670,8 @@ static int audit_filter_rules(struct task_struct *tsk,
>  				/* Find ipc objects that match */
>  				if (!ctx || ctx->type != AUDIT_IPC)
>  					break;
> -				if (security_audit_rule_match(ctx->ipc.osid,
> +				lsmblob_init(&blob, ctx->ipc.osid);
> +				if (security_audit_rule_match(&blob,
>  							      f->type, f->op,
>  							      f->lsm_rule))
>  					++result;
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index d213e835c498..5a337239d9e4 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -307,8 +307,8 @@ static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
>  	return -EINVAL;
>  }
>  
> -static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
> -					     void *lsmrule)
> +static inline int security_filter_rule_match(struct lsmblob *blob, u32 field,
> +					     u32 op, void *lsmrule)
>  {
>  	return -EINVAL;
>  }
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index e0cc323f948f..e7b8ce942950 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -327,6 +327,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  	for (i = 0; i < MAX_LSM_RULES; i++) {
>  		int rc = 0;
>  		u32 osid;
> +		struct lsmblob blob;
>  		int retried = 0;
>  
>  		if (!rule->lsm[i].rule)
> @@ -337,7 +338,8 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  		case LSM_OBJ_ROLE:
>  		case LSM_OBJ_TYPE:
>  			security_inode_getsecid(inode, &osid);
> -			rc = security_filter_rule_match(osid,
> +			lsmblob_init(&blob, osid);
> +			rc = security_filter_rule_match(&blob,
>  							rule->lsm[i].type,
>  							Audit_equal,
>  							rule->lsm[i].rule);
> @@ -345,7 +347,8 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  		case LSM_SUBJ_USER:
>  		case LSM_SUBJ_ROLE:
>  		case LSM_SUBJ_TYPE:
> -			rc = security_filter_rule_match(secid,
> +			lsmblob_init(&blob, secid);
> +			rc = security_filter_rule_match(&blob,
>  							rule->lsm[i].type,
>  							Audit_equal,
>  							rule->lsm[i].rule);
> diff --git a/security/security.c b/security/security.c
> index 7618c761060d..4692f44718c6 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2452,9 +2452,19 @@ void security_audit_rule_free(void *lsmrule)
>  	call_void_hook(audit_rule_free, lsmrule);
>  }
>  
> -int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
> +int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
> +			      void *lsmrule)
>  {
> -	return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule);
> +	struct security_hook_list *hp;
> +	int rc;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) {
> +		rc = hp->hook.audit_rule_match(blob->secid[hp->slot], field,
> +					       op, lsmrule);
> +		if (rc != 0)
> +			return rc;
> +	}
> +	return 0;
>  }
>  #endif /* CONFIG_AUDIT */
>  
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 06/24] LSM: Use lsmblob in security_kernel_act_as
  2019-06-21 18:52 ` [PATCH v3 06/24] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
@ 2019-06-22 22:43   ` Kees Cook
  2019-06-24 18:38   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:43 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:15AM -0700, Casey Schaufler wrote:
> Change the security_kernel_act_as interface to use a lsmblob
> structure in place of the single u32 secid in support of
> module stacking. Change it's only caller, set_security_override,
> to do the same. Change that one's only caller,
> set_security_override_from_ctx, to call it with the new
> parameter type.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  include/linux/cred.h     |  3 ++-
>  include/linux/security.h |  5 +++--
>  kernel/cred.c            | 10 ++++++----
>  security/security.c      | 12 ++++++++++--
>  4 files changed, 21 insertions(+), 9 deletions(-)
> 
> diff --git a/include/linux/cred.h b/include/linux/cred.h
> index efb6edf32de7..9a21c376ed97 100644
> --- a/include/linux/cred.h
> +++ b/include/linux/cred.h
> @@ -22,6 +22,7 @@
>  
>  struct cred;
>  struct inode;
> +struct lsmblob;
>  
>  /*
>   * COW Supplementary groups list
> @@ -165,7 +166,7 @@ extern const struct cred *override_creds(const struct cred *);
>  extern void revert_creds(const struct cred *);
>  extern struct cred *prepare_kernel_cred(struct task_struct *);
>  extern int change_create_files_as(struct cred *, struct inode *);
> -extern int set_security_override(struct cred *, u32);
> +extern int set_security_override(struct cred *, struct lsmblob *);
>  extern int set_security_override_from_ctx(struct cred *, const char *);
>  extern int set_create_files_as(struct cred *, struct inode *);
>  extern int cred_fscmp(const struct cred *, const struct cred *);
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 52d89c4a9594..4a78516cc74a 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -384,7 +384,7 @@ void security_cred_free(struct cred *cred);
>  int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
>  void security_transfer_creds(struct cred *new, const struct cred *old);
>  void security_cred_getsecid(const struct cred *c, u32 *secid);
> -int security_kernel_act_as(struct cred *new, u32 secid);
> +int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
>  int security_kernel_create_files_as(struct cred *new, struct inode *inode);
>  int security_kernel_module_request(char *kmod_name);
>  int security_kernel_load_data(enum kernel_load_data_id id);
> @@ -967,7 +967,8 @@ static inline void security_transfer_creds(struct cred *new,
>  {
>  }
>  
> -static inline int security_kernel_act_as(struct cred *cred, u32 secid)
> +static inline int security_kernel_act_as(struct cred *cred,
> +					 struct lsmblob *blob)
>  {
>  	return 0;
>  }
> diff --git a/kernel/cred.c b/kernel/cred.c
> index 45d77284aed0..71c14dda107e 100644
> --- a/kernel/cred.c
> +++ b/kernel/cred.c
> @@ -701,14 +701,14 @@ EXPORT_SYMBOL(prepare_kernel_cred);
>  /**
>   * set_security_override - Set the security ID in a set of credentials
>   * @new: The credentials to alter
> - * @secid: The LSM security ID to set
> + * @blob: The LSM security information to set
>   *
>   * Set the LSM security ID in a set of credentials so that the subjective
>   * security is overridden when an alternative set of credentials is used.
>   */
> -int set_security_override(struct cred *new, u32 secid)
> +int set_security_override(struct cred *new, struct lsmblob *blob)
>  {
> -	return security_kernel_act_as(new, secid);
> +	return security_kernel_act_as(new, blob);
>  }
>  EXPORT_SYMBOL(set_security_override);
>  
> @@ -724,6 +724,7 @@ EXPORT_SYMBOL(set_security_override);
>   */
>  int set_security_override_from_ctx(struct cred *new, const char *secctx)
>  {
> +	struct lsmblob blob;
>  	u32 secid;
>  	int ret;
>  
> @@ -731,7 +732,8 @@ int set_security_override_from_ctx(struct cred *new, const char *secctx)
>  	if (ret < 0)
>  		return ret;
>  
> -	return set_security_override(new, secid);
> +	lsmblob_init(&blob, secid);
> +	return set_security_override(new, &blob);
>  }
>  EXPORT_SYMBOL(set_security_override_from_ctx);
>  
> diff --git a/security/security.c b/security/security.c
> index 4692f44718c6..43f8018b9e13 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1646,9 +1646,17 @@ void security_cred_getsecid(const struct cred *c, u32 *secid)
>  }
>  EXPORT_SYMBOL(security_cred_getsecid);
>  
> -int security_kernel_act_as(struct cred *new, u32 secid)
> +int security_kernel_act_as(struct cred *new, struct lsmblob *blob)
>  {
> -	return call_int_hook(kernel_act_as, 0, new, secid);
> +	struct security_hook_list *hp;
> +	int rc;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.kernel_act_as, list) {
> +		rc = hp->hook.kernel_act_as(new, blob->secid[hp->slot]);
> +		if (rc != 0)
> +			return rc;
> +	}
> +	return 0;
>  }
>  
>  int security_kernel_create_files_as(struct cred *new, struct inode *inode)
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 07/24] net: Prepare UDS for secuirty module stacking
  2019-06-21 18:52 ` [PATCH v3 07/24] net: Prepare UDS for secuirty module stacking Casey Schaufler
@ 2019-06-22 22:43   ` Kees Cook
  2019-06-24 18:39   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:43 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:16AM -0700, Casey Schaufler wrote:
> Change the data used in UDS SO_PEERSEC processing from a
> secid to a more general struct lsmblob. Update the
> security_socket_getpeersec_dgram() interface to use the
> lsmblob. There is a small amount of scaffolding code
> that will come out when the security_secid_to_secctx()
> code is brought in line with the lsmblob.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  include/linux/security.h |  7 +++++--
>  include/net/af_unix.h    |  2 +-
>  include/net/scm.h        |  8 +++++---
>  net/ipv4/ip_sockglue.c   |  8 +++++---
>  net/unix/af_unix.c       |  6 +++---
>  security/security.c      | 16 +++++++++++++---
>  6 files changed, 32 insertions(+), 15 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 4a78516cc74a..905830a90745 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -1276,7 +1276,8 @@ int security_socket_shutdown(struct socket *sock, int how);
>  int security_sock_rcv_skb(struct sock *sk, struct sk_buff *skb);
>  int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
>  				      int __user *optlen, unsigned len);
> -int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid);
> +int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
> +				     struct lsmblob *blob);
>  int security_sk_alloc(struct sock *sk, int family, gfp_t priority);
>  void security_sk_free(struct sock *sk);
>  void security_sk_clone(const struct sock *sk, struct sock *newsk);
> @@ -1414,7 +1415,9 @@ static inline int security_socket_getpeersec_stream(struct socket *sock, char __
>  	return -ENOPROTOOPT;
>  }
>  
> -static inline int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
> +static inline int security_socket_getpeersec_dgram(struct socket *sock,
> +						   struct sk_buff *skb,
> +						   struct lsmblob *blob)
>  {
>  	return -ENOPROTOOPT;
>  }
> diff --git a/include/net/af_unix.h b/include/net/af_unix.h
> index 3426d6dacc45..933492c08b8c 100644
> --- a/include/net/af_unix.h
> +++ b/include/net/af_unix.h
> @@ -36,7 +36,7 @@ struct unix_skb_parms {
>  	kgid_t			gid;
>  	struct scm_fp_list	*fp;		/* Passed files		*/
>  #ifdef CONFIG_SECURITY_NETWORK
> -	u32			secid;		/* Security ID		*/
> +	struct lsmblob		lsmblob;	/* Security LSM data	*/
>  #endif
>  	u32			consumed;
>  } __randomize_layout;
> diff --git a/include/net/scm.h b/include/net/scm.h
> index 1ce365f4c256..e2e71c4bf9d0 100644
> --- a/include/net/scm.h
> +++ b/include/net/scm.h
> @@ -33,7 +33,7 @@ struct scm_cookie {
>  	struct scm_fp_list	*fp;		/* Passed files		*/
>  	struct scm_creds	creds;		/* Skb credentials	*/
>  #ifdef CONFIG_SECURITY_NETWORK
> -	u32			secid;		/* Passed security ID 	*/
> +	struct lsmblob		lsmblob;	/* Passed LSM data	*/
>  #endif
>  };
>  
> @@ -46,7 +46,7 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl);
>  #ifdef CONFIG_SECURITY_NETWORK
>  static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
>  {
> -	security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
> +	security_socket_getpeersec_dgram(sock, NULL, &scm->lsmblob);
>  }
>  #else
>  static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
> @@ -97,7 +97,9 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
>  	int err;
>  
>  	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
> -		err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
> +		/* Scaffolding - it has to be element 0 for now */
> +		err = security_secid_to_secctx(scm->lsmblob.secid[0],
> +					       &secdata, &seclen);
>  
>  		if (!err) {
>  			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index 82f341e84fae..2a5c868ce135 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -130,15 +130,17 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
>  
>  static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
>  {
> +	struct lsmblob lb;
>  	char *secdata;
> -	u32 seclen, secid;
> +	u32 seclen;
>  	int err;
>  
> -	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
> +	err = security_socket_getpeersec_dgram(NULL, skb, &lb);
>  	if (err)
>  		return;
>  
> -	err = security_secid_to_secctx(secid, &secdata, &seclen);
> +	/* Scaffolding - it has to be element 0 */
> +	err = security_secid_to_secctx(lb.secid[0], &secdata, &seclen);
>  	if (err)
>  		return;
>  
> diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
> index ddb838a1b74c..c50a004a1389 100644
> --- a/net/unix/af_unix.c
> +++ b/net/unix/af_unix.c
> @@ -143,17 +143,17 @@ static struct hlist_head *unix_sockets_unbound(void *addr)
>  #ifdef CONFIG_SECURITY_NETWORK
>  static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
>  {
> -	UNIXCB(skb).secid = scm->secid;
> +	UNIXCB(skb).lsmblob = scm->lsmblob;
>  }
>  
>  static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
>  {
> -	scm->secid = UNIXCB(skb).secid;
> +	scm->lsmblob = UNIXCB(skb).lsmblob;
>  }
>  
>  static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
>  {
> -	return (scm->secid == UNIXCB(skb).secid);
> +	return lsmblob_equal(&scm->lsmblob, &(UNIXCB(skb).lsmblob));
>  }
>  #else
>  static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
> diff --git a/security/security.c b/security/security.c
> index 43f8018b9e13..c7b3d1a294ad 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2137,10 +2137,20 @@ int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
>  				optval, optlen, len);
>  }
>  
> -int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
> +int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
> +				     struct lsmblob *blob)
>  {
> -	return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock,
> -			     skb, secid);
> +	struct security_hook_list *hp;
> +	int rc = -ENOPROTOOPT;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_dgram,
> +			     list) {
> +		rc = hp->hook.socket_getpeersec_dgram(sock, skb,
> +						      &blob->secid[hp->slot]);
> +		if (rc != 0)
> +			break;
> +	}
> +	return rc;
>  }
>  EXPORT_SYMBOL(security_socket_getpeersec_dgram);
>  
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 08/24] LSM: Use lsmblob in security_secctx_to_secid
  2019-06-21 18:52 ` [PATCH v3 08/24] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
@ 2019-06-22 22:44   ` Kees Cook
  2019-06-24 18:38   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:44 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:17AM -0700, Casey Schaufler wrote:
> Change security_secctx_to_secid() to fill in a lsmblob instead
> of a u32 secid. Multiple LSMs may be able to interpret the
> string, and this allows for setting whichever secid is
> appropriate. In some cases there is scaffolding where other
> interfaces have yet to be converted.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  include/linux/security.h          |  5 +++--
>  kernel/cred.c                     |  4 +---
>  net/netfilter/nft_meta.c          | 13 ++++++-------
>  net/netfilter/xt_SECMARK.c        |  5 ++++-
>  net/netlabel/netlabel_unlabeled.c | 14 ++++++++------
>  security/security.c               | 16 +++++++++++++---
>  6 files changed, 35 insertions(+), 22 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 905830a90745..b0395d224c43 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -443,7 +443,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>  int security_netlink_send(struct sock *sk, struct sk_buff *skb);
>  int security_ismaclabel(const char *name);
>  int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
> -int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
> +int security_secctx_to_secid(const char *secdata, u32 seclen,
> +			     struct lsmblob *blob);
>  void security_release_secctx(char *secdata, u32 seclen);
>  
>  void security_inode_invalidate_secctx(struct inode *inode);
> @@ -1226,7 +1227,7 @@ static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *secle
>  
>  static inline int security_secctx_to_secid(const char *secdata,
>  					   u32 seclen,
> -					   u32 *secid)
> +					   struct lsmblob *blob)
>  {
>  	return -EOPNOTSUPP;
>  }
> diff --git a/kernel/cred.c b/kernel/cred.c
> index 71c14dda107e..d70a2c02ced4 100644
> --- a/kernel/cred.c
> +++ b/kernel/cred.c
> @@ -725,14 +725,12 @@ EXPORT_SYMBOL(set_security_override);
>  int set_security_override_from_ctx(struct cred *new, const char *secctx)
>  {
>  	struct lsmblob blob;
> -	u32 secid;
>  	int ret;
>  
> -	ret = security_secctx_to_secid(secctx, strlen(secctx), &secid);
> +	ret = security_secctx_to_secid(secctx, strlen(secctx), &blob);
>  	if (ret < 0)
>  		return ret;
>  
> -	lsmblob_init(&blob, secid);
>  	return set_security_override(new, &blob);
>  }
>  EXPORT_SYMBOL(set_security_override_from_ctx);
> diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
> index 987d2d6ce624..91973d3a5f6a 100644
> --- a/net/netfilter/nft_meta.c
> +++ b/net/netfilter/nft_meta.c
> @@ -576,21 +576,20 @@ static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = {
>  
>  static int nft_secmark_compute_secid(struct nft_secmark *priv)
>  {
> -	u32 tmp_secid = 0;
> +	struct lsmblob blob;
>  	int err;
>  
> -	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
> +	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &blob);
>  	if (err)
>  		return err;
>  
> -	if (!tmp_secid)
> -		return -ENOENT;
> -
> -	err = security_secmark_relabel_packet(tmp_secid);
> +	/* Using le[0] is scaffolding */
> +	err = security_secmark_relabel_packet(blob.secid[0]);
>  	if (err)
>  		return err;
>  
> -	priv->secid = tmp_secid;
> +	/* Using le[1] is scaffolding */
> +	priv->secid = blob.secid[0];
>  	return 0;
>  }
>  
> diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
> index f16202d26c20..8081fadc30e9 100644
> --- a/net/netfilter/xt_SECMARK.c
> +++ b/net/netfilter/xt_SECMARK.c
> @@ -49,13 +49,14 @@ secmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
>  
>  static int checkentry_lsm(struct xt_secmark_target_info *info)
>  {
> +	struct lsmblob blob;
>  	int err;
>  
>  	info->secctx[SECMARK_SECCTX_MAX - 1] = '\0';
>  	info->secid = 0;
>  
>  	err = security_secctx_to_secid(info->secctx, strlen(info->secctx),
> -				       &info->secid);
> +				       &blob);
>  	if (err) {
>  		if (err == -EINVAL)
>  			pr_info_ratelimited("invalid security context \'%s\'\n",
> @@ -63,6 +64,8 @@ static int checkentry_lsm(struct xt_secmark_target_info *info)
>  		return err;
>  	}
>  
> +	/* scaffolding during the transition */
> +	info->secid = blob.secid[0];
>  	if (!info->secid) {
>  		pr_info_ratelimited("unable to map security context \'%s\'\n",
>  				    info->secctx);
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index c92894c3e40a..2976370e41aa 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -895,7 +895,7 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
>  	void *addr;
>  	void *mask;
>  	u32 addr_len;
> -	u32 secid;
> +	struct lsmblob blob;
>  	struct netlbl_audit audit_info;
>  
>  	/* Don't allow users to add both IPv4 and IPv6 addresses for a
> @@ -919,12 +919,13 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
>  	ret_val = security_secctx_to_secid(
>  		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
>  				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
> -				  &secid);
> +				  &blob);
>  	if (ret_val != 0)
>  		return ret_val;
>  
> +	/* scaffolding with the [0] */
>  	return netlbl_unlhsh_add(&init_net,
> -				 dev_name, addr, mask, addr_len, secid,
> +				 dev_name, addr, mask, addr_len, blob.secid[0],
>  				 &audit_info);
>  }
>  
> @@ -946,7 +947,7 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
>  	void *addr;
>  	void *mask;
>  	u32 addr_len;
> -	u32 secid;
> +	struct lsmblob blob;
>  	struct netlbl_audit audit_info;
>  
>  	/* Don't allow users to add both IPv4 and IPv6 addresses for a
> @@ -968,12 +969,13 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
>  	ret_val = security_secctx_to_secid(
>  		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
>  				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
> -				  &secid);
> +				  &blob);
>  	if (ret_val != 0)
>  		return ret_val;
>  
> +	/* scaffolding with the [0] */
>  	return netlbl_unlhsh_add(&init_net,
> -				 NULL, addr, mask, addr_len, secid,
> +				 NULL, addr, mask, addr_len, blob.secid[0],
>  				 &audit_info);
>  }
>  
> diff --git a/security/security.c b/security/security.c
> index c7b3d1a294ad..cb1545bfe8c5 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1999,10 +1999,20 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
>  }
>  EXPORT_SYMBOL(security_secid_to_secctx);
>  
> -int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
> +int security_secctx_to_secid(const char *secdata, u32 seclen,
> +			     struct lsmblob *blob)
>  {
> -	*secid = 0;
> -	return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid);
> +	struct security_hook_list *hp;
> +	int rc;
> +
> +	lsmblob_init(blob, 0);
> +	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
> +		rc = hp->hook.secctx_to_secid(secdata, seclen,
> +					      &blob->secid[hp->slot]);
> +		if (rc != 0)
> +			return rc;
> +	}
> +	return 0;
>  }
>  EXPORT_SYMBOL(security_secctx_to_secid);
>  
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 09/24] LSM: Use lsmblob in security_secid_to_secctx
  2019-06-21 18:52 ` [PATCH v3 09/24] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
@ 2019-06-22 22:44   ` Kees Cook
  2019-06-24 18:39   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:44 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:18AM -0700, Casey Schaufler wrote:
> Change security_secid_to_secctx() to take a lsmblob as input
> instead of a u32 secid. It will then call the LSM hooks
> using the lsmblob element allocated for that module. The
> callers have been updated as well. This allows for the
> possibility that more than one module may called upon
> to translate a secid to a string, as can occur in the
> audit code.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  drivers/android/binder.c                |  4 +++-
>  include/linux/security.h                |  5 +++--
>  include/net/scm.h                       |  5 ++---
>  kernel/audit.c                          |  9 +++++++--
>  kernel/auditsc.c                        | 14 ++++++++++----
>  net/ipv4/ip_sockglue.c                  |  3 +--
>  net/netfilter/nf_conntrack_netlink.c    |  8 ++++++--
>  net/netfilter/nf_conntrack_standalone.c |  4 +++-
>  net/netfilter/nfnetlink_queue.c         |  8 ++++++--
>  net/netlabel/netlabel_unlabeled.c       | 18 ++++++++++++++----
>  net/netlabel/netlabel_user.c            |  6 +++---
>  security/security.c                     | 14 +++++++++++---
>  12 files changed, 69 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 8685882da64c..1962f6b8abd0 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -3120,9 +3120,11 @@ static void binder_transaction(struct binder_proc *proc,
>  
>  	if (target_node && target_node->txn_security_ctx) {
>  		u32 secid;
> +		struct lsmblob blob;
>  
>  		security_task_getsecid(proc->tsk, &secid);
> -		ret = security_secid_to_secctx(secid, &secctx, &secctx_sz);
> +		lsmblob_init(&blob, secid);
> +		ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
>  		if (ret) {
>  			return_error = BR_FAILED_REPLY;
>  			return_error_param = ret;
> diff --git a/include/linux/security.h b/include/linux/security.h
> index b0395d224c43..c6cddeff8a17 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -442,7 +442,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>  			 size_t size);
>  int security_netlink_send(struct sock *sk, struct sk_buff *skb);
>  int security_ismaclabel(const char *name);
> -int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
> +int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
>  int security_secctx_to_secid(const char *secdata, u32 seclen,
>  			     struct lsmblob *blob);
>  void security_release_secctx(char *secdata, u32 seclen);
> @@ -1220,7 +1220,8 @@ static inline int security_ismaclabel(const char *name)
>  	return 0;
>  }
>  
> -static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
> +static inline int security_secid_to_secctx(struct lsmblob *blob,
> +					   char **secdata, u32 *seclen)
>  {
>  	return -EOPNOTSUPP;
>  }
> diff --git a/include/net/scm.h b/include/net/scm.h
> index e2e71c4bf9d0..31ae605fcc0a 100644
> --- a/include/net/scm.h
> +++ b/include/net/scm.h
> @@ -97,9 +97,8 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
>  	int err;
>  
>  	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
> -		/* Scaffolding - it has to be element 0 for now */
> -		err = security_secid_to_secctx(scm->lsmblob.secid[0],
> -					       &secdata, &seclen);
> +		err = security_secid_to_secctx(&scm->lsmblob, &secdata,
> +					       &seclen);
>  
>  		if (!err) {
>  			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
> diff --git a/kernel/audit.c b/kernel/audit.c
> index c89ea48c70a6..d0338411d75d 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -1430,7 +1430,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
>  	case AUDIT_SIGNAL_INFO:
>  		len = 0;
>  		if (audit_sig_sid) {
> -			err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
> +			struct lsmblob blob;
> +
> +			lsmblob_init(&blob, audit_sig_sid);
> +			err = security_secid_to_secctx(&blob, &ctx, &len);
>  			if (err)
>  				return err;
>  		}
> @@ -2073,12 +2076,14 @@ int audit_log_task_context(struct audit_buffer *ab)
>  	unsigned len;
>  	int error;
>  	u32 sid;
> +	struct lsmblob blob;
>  
>  	security_task_getsecid(current, &sid);
>  	if (!sid)
>  		return 0;
>  
> -	error = security_secid_to_secctx(sid, &ctx, &len);
> +	lsmblob_init(&blob, sid);
> +	error = security_secid_to_secctx(&blob, &ctx, &len);
>  	if (error) {
>  		if (error != -EINVAL)
>  			goto error_path;
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 18ee5556c086..d31914088a82 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -947,6 +947,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  	char *ctx = NULL;
>  	u32 len;
>  	int rc = 0;
> +	struct lsmblob blob;
>  
>  	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
>  	if (!ab)
> @@ -956,7 +957,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  			 from_kuid(&init_user_ns, auid),
>  			 from_kuid(&init_user_ns, uid), sessionid);
>  	if (sid) {
> -		if (security_secid_to_secctx(sid, &ctx, &len)) {
> +		lsmblob_init(&blob, sid);
> +		if (security_secid_to_secctx(&blob, &ctx, &len)) {
>  			audit_log_format(ab, " obj=(none)");
>  			rc = 1;
>  		} else {
> @@ -1198,7 +1200,10 @@ static void show_special(struct audit_context *context, int *call_panic)
>  		if (osid) {
>  			char *ctx = NULL;
>  			u32 len;
> -			if (security_secid_to_secctx(osid, &ctx, &len)) {
> +			struct lsmblob blob;
> +
> +			lsmblob_init(&blob, osid);
> +			if (security_secid_to_secctx(&blob, &ctx, &len)) {
>  				audit_log_format(ab, " osid=%u", osid);
>  				*call_panic = 1;
>  			} else {
> @@ -1349,9 +1354,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
>  	if (n->osid != 0) {
>  		char *ctx = NULL;
>  		u32 len;
> +		struct lsmblob blob;
>  
> -		if (security_secid_to_secctx(
> -			n->osid, &ctx, &len)) {
> +		lsmblob_init(&blob, n->osid);
> +		if (security_secid_to_secctx(&blob, &ctx, &len)) {
>  			audit_log_format(ab, " osid=%u", n->osid);
>  			if (call_panic)
>  				*call_panic = 2;
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index 2a5c868ce135..e05f4ef68bd8 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -139,8 +139,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
>  	if (err)
>  		return;
>  
> -	/* Scaffolding - it has to be element 0 */
> -	err = security_secid_to_secctx(lb.secid[0], &secdata, &seclen);
> +	err = security_secid_to_secctx(&lb, &secdata, &seclen);
>  	if (err)
>  		return;
>  
> diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
> index 66c596d287a5..ca0968f13240 100644
> --- a/net/netfilter/nf_conntrack_netlink.c
> +++ b/net/netfilter/nf_conntrack_netlink.c
> @@ -330,8 +330,10 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
>  	struct nlattr *nest_secctx;
>  	int len, ret;
>  	char *secctx;
> +	struct lsmblob blob;
>  
> -	ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
> +	lsmblob_init(&blob, ct->secmark);
> +	ret = security_secid_to_secctx(&blob, &secctx, &len);
>  	if (ret)
>  		return 0;
>  
> @@ -615,8 +617,10 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
>  {
>  #ifdef CONFIG_NF_CONNTRACK_SECMARK
>  	int len, ret;
> +	struct lsmblob blob;
>  
> -	ret = security_secid_to_secctx(ct->secmark, NULL, &len);
> +	lsmblob_init(&blob, ct->secmark);
> +	ret = security_secid_to_secctx(&blob, NULL, &len);
>  	if (ret)
>  		return 0;
>  
> diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
> index c2ae14c720b4..c793103f3cd7 100644
> --- a/net/netfilter/nf_conntrack_standalone.c
> +++ b/net/netfilter/nf_conntrack_standalone.c
> @@ -175,8 +175,10 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
>  	int ret;
>  	u32 len;
>  	char *secctx;
> +	struct lsmblob blob;
>  
> -	ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
> +	lsmblob_init(&blob, ct->secmark);
> +	ret = security_secid_to_secctx(&blob, &secctx, &len);
>  	if (ret)
>  		return;
>  
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index 0dcc3592d053..59211bff90ab 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -309,13 +309,17 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
>  {
>  	u32 seclen = 0;
>  #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
> +	struct lsmblob blob;
> +
>  	if (!skb || !sk_fullsock(skb->sk))
>  		return 0;
>  
>  	read_lock_bh(&skb->sk->sk_callback_lock);
>  
> -	if (skb->secmark)
> -		security_secid_to_secctx(skb->secmark, secdata, &seclen);
> +	if (skb->secmark) {
> +		lsmblob_init(&blob, skb->secmark);
> +		security_secid_to_secctx(&blob, secdata, &seclen);
> +	}
>  
>  	read_unlock_bh(&skb->sk->sk_callback_lock);
>  #endif
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 2976370e41aa..2d8dd5b84457 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -389,6 +389,7 @@ int netlbl_unlhsh_add(struct net *net,
>  	struct audit_buffer *audit_buf = NULL;
>  	char *secctx = NULL;
>  	u32 secctx_len;
> +	struct lsmblob blob;
>  
>  	if (addr_len != sizeof(struct in_addr) &&
>  	    addr_len != sizeof(struct in6_addr))
> @@ -451,7 +452,8 @@ int netlbl_unlhsh_add(struct net *net,
>  unlhsh_add_return:
>  	rcu_read_unlock();
>  	if (audit_buf != NULL) {
> -		if (security_secid_to_secctx(secid,
> +		lsmblob_init(&blob, secid);
> +		if (security_secid_to_secctx(&blob,
>  					     &secctx,
>  					     &secctx_len) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> @@ -488,6 +490,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  	struct net_device *dev;
>  	char *secctx;
>  	u32 secctx_len;
> +	struct lsmblob blob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
>  	list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
> @@ -507,8 +510,10 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  					  addr->s_addr, mask->s_addr);
>  		if (dev != NULL)
>  			dev_put(dev);
> +		if (entry != NULL)
> +			lsmblob_init(&blob, entry->secid);
>  		if (entry != NULL &&
> -		    security_secid_to_secctx(entry->secid,
> +		    security_secid_to_secctx(&blob,
>  					     &secctx, &secctx_len) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
>  			security_release_secctx(secctx, secctx_len);
> @@ -550,6 +555,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  	struct net_device *dev;
>  	char *secctx;
>  	u32 secctx_len;
> +	struct lsmblob blob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
>  	list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
> @@ -568,8 +574,10 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  					  addr, mask);
>  		if (dev != NULL)
>  			dev_put(dev);
> +		if (entry != NULL)
> +			lsmblob_init(&blob, entry->secid);
>  		if (entry != NULL &&
> -		    security_secid_to_secctx(entry->secid,
> +		    security_secid_to_secctx(&blob,
>  					     &secctx, &secctx_len) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
>  			security_release_secctx(secctx, secctx_len);
> @@ -1090,6 +1098,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  	u32 secid;
>  	char *secctx;
>  	u32 secctx_len;
> +	struct lsmblob blob;
>  
>  	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
>  			   cb_arg->seq, &netlbl_unlabel_gnl_family,
> @@ -1144,7 +1153,8 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  		secid = addr6->secid;
>  	}
>  
> -	ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
> +	lsmblob_init(&blob, secid);
> +	ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
>  	if (ret_val != 0)
>  		goto list_cb_failure;
>  	ret_val = nla_put(cb_arg->skb,
> diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
> index 4676f5bb16ae..2ccc6567e2a2 100644
> --- a/net/netlabel/netlabel_user.c
> +++ b/net/netlabel/netlabel_user.c
> @@ -100,6 +100,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>  	struct audit_buffer *audit_buf;
>  	char *secctx;
>  	u32 secctx_len;
> +	struct lsmblob blob;
>  
>  	if (audit_enabled == AUDIT_OFF)
>  		return NULL;
> @@ -112,10 +113,9 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>  			 from_kuid(&init_user_ns, audit_info->loginuid),
>  			 audit_info->sessionid);
>  
> +	lsmblob_init(&blob, audit_info->secid);
>  	if (audit_info->secid != 0 &&
> -	    security_secid_to_secctx(audit_info->secid,
> -				     &secctx,
> -				     &secctx_len) == 0) {
> +	    security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
>  		audit_log_format(audit_buf, " subj=%s", secctx);
>  		security_release_secctx(secctx, secctx_len);
>  	}
> diff --git a/security/security.c b/security/security.c
> index cb1545bfe8c5..5ab07631df75 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1992,10 +1992,18 @@ int security_ismaclabel(const char *name)
>  }
>  EXPORT_SYMBOL(security_ismaclabel);
>  
> -int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
> +int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
>  {
> -	return call_int_hook(secid_to_secctx, -EOPNOTSUPP, secid, secdata,
> -				seclen);
> +	struct security_hook_list *hp;
> +	int rc;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
> +		rc = hp->hook.secid_to_secctx(blob->secid[hp->slot],
> +					      secdata, seclen);
> +		if (rc != 0)
> +			return rc;
> +	}
> +	return 0;
>  }
>  EXPORT_SYMBOL(security_secid_to_secctx);
>  
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 10/24] Use lsmblob in security_ipc_getsecid
  2019-06-21 18:52 ` [PATCH v3 10/24] Use lsmblob in security_ipc_getsecid Casey Schaufler
@ 2019-06-22 22:48   ` Kees Cook
  2019-06-24 16:39     ` Casey Schaufler
  2019-06-24 18:39   ` John Johansen
  1 sibling, 1 reply; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:48 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:19AM -0700, Casey Schaufler wrote:
> There may be more than one LSM that provides IPC data
> for auditing. Change security_ipc_getsecid() to fill in
> a lsmblob structure instead of the u32 secid. The
> audit data structure containing the secid will be updated
> later, so there is a bit of scaffolding here.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

One thought below...

> ---
>  include/linux/security.h | 7 ++++---
>  kernel/auditsc.c         | 5 ++++-
>  security/security.c      | 9 ++++++---
>  3 files changed, 14 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index c6cddeff8a17..0d5e172341fc 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -413,7 +413,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
>  			unsigned long arg4, unsigned long arg5);
>  void security_task_to_inode(struct task_struct *p, struct inode *inode);
>  int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
> -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid);
> +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob);
>  int security_msg_msg_alloc(struct msg_msg *msg);
>  void security_msg_msg_free(struct msg_msg *msg);
>  int security_msg_queue_alloc(struct kern_ipc_perm *msq);
> @@ -1098,9 +1098,10 @@ static inline int security_ipc_permission(struct kern_ipc_perm *ipcp,
>  	return 0;
>  }
>  
> -static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
> +static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp,
> +					 struct lsmblob *blob)
>  {
> -	*secid = 0;
> +	lsmblob_init(blob, 0);
>  }
>  
>  static inline int security_msg_msg_alloc(struct msg_msg *msg)
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index d31914088a82..148733ec3c72 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -2268,11 +2268,14 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
>  void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
>  {
>  	struct audit_context *context = audit_context();
> +	struct lsmblob blob;
>  	context->ipc.uid = ipcp->uid;
>  	context->ipc.gid = ipcp->gid;
>  	context->ipc.mode = ipcp->mode;
>  	context->ipc.has_perm = 0;
> -	security_ipc_getsecid(ipcp, &context->ipc.osid);
> +	security_ipc_getsecid(ipcp, &blob);
> +	/* scaffolding on the [0] - change "osid" to a lsmblob */
> +	context->ipc.osid = blob.secid[0];
>  	context->type = AUDIT_IPC;
>  }
>  
> diff --git a/security/security.c b/security/security.c
> index 5ab07631df75..d55f01041f05 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1812,10 +1812,13 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
>  	return call_int_hook(ipc_permission, 0, ipcp, flag);
>  }
>  
> -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
> +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob)
>  {
> -	*secid = 0;
> -	call_void_hook(ipc_getsecid, ipcp, secid);
> +	struct security_hook_list *hp;
> +
> +	lsmblob_init(blob, 0);
> +	hlist_for_each_entry(hp, &security_hook_heads.ipc_getsecid, list)
> +		hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->slot]);

Just for sanity when using hp->slot, it might be good to do something
like this in the places it gets used. Like for here:

	if (!WARN_ON(hp->slot < 0 || hp->slot >= LSMBLOB_COUNT))
		hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->slot]);

This _should_ be overkill, but since lists of hooks that trigger slot
assignment is hardcoded, it seems nice to cover any future problems or
mismatches.

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 11/24] LSM: Use lsmblob in security_task_getsecid
  2019-06-21 18:52 ` [PATCH v3 11/24] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
@ 2019-06-22 22:49   ` Kees Cook
  2019-06-24 18:40   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:49 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:20AM -0700, Casey Schaufler wrote:
> Change the security_task_getsecid() interface to fill in
> a lsmblob structure instead of a u32 secid in support of
> LSM stacking. Audit interfaces will need to collect all
> possible secids for possible reporting.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  drivers/android/binder.c              |  4 +---
>  include/linux/security.h              |  7 +++---
>  kernel/audit.c                        |  6 ++---
>  kernel/auditfilter.c                  |  4 +---
>  kernel/auditsc.c                      | 22 ++++++++++++------
>  net/netlabel/netlabel_unlabeled.c     |  5 +++-
>  net/netlabel/netlabel_user.h          |  6 ++++-
>  security/integrity/ima/ima_appraise.c |  4 +++-
>  security/integrity/ima/ima_main.c     | 33 +++++++++++++++------------
>  security/security.c                   |  9 +++++---
>  10 files changed, 60 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 1962f6b8abd0..144ac4f1c24f 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -3119,11 +3119,9 @@ static void binder_transaction(struct binder_proc *proc,
>  	t->priority = task_nice(current);
>  
>  	if (target_node && target_node->txn_security_ctx) {
> -		u32 secid;
>  		struct lsmblob blob;
>  
> -		security_task_getsecid(proc->tsk, &secid);
> -		lsmblob_init(&blob, secid);
> +		security_task_getsecid(proc->tsk, &blob);
>  		ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
>  		if (ret) {
>  			return_error = BR_FAILED_REPLY;
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 0d5e172341fc..c5fdaaff8806 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -396,7 +396,7 @@ int security_task_fix_setuid(struct cred *new, const struct cred *old,
>  int security_task_setpgid(struct task_struct *p, pid_t pgid);
>  int security_task_getpgid(struct task_struct *p);
>  int security_task_getsid(struct task_struct *p);
> -void security_task_getsecid(struct task_struct *p, u32 *secid);
> +void security_task_getsecid(struct task_struct *p, struct lsmblob *blob);
>  int security_task_setnice(struct task_struct *p, int nice);
>  int security_task_setioprio(struct task_struct *p, int ioprio);
>  int security_task_getioprio(struct task_struct *p);
> @@ -1025,9 +1025,10 @@ static inline int security_task_getsid(struct task_struct *p)
>  	return 0;
>  }
>  
> -static inline void security_task_getsecid(struct task_struct *p, u32 *secid)
> +static inline void security_task_getsecid(struct task_struct *p,
> +					  struct lsmblob *blob)
>  {
> -	*secid = 0;
> +	lsmblob_init(blob, 0);
>  }
>  
>  static inline int security_task_setnice(struct task_struct *p, int nice)
> diff --git a/kernel/audit.c b/kernel/audit.c
> index d0338411d75d..a0205f3c23c7 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -2075,14 +2075,12 @@ int audit_log_task_context(struct audit_buffer *ab)
>  	char *ctx = NULL;
>  	unsigned len;
>  	int error;
> -	u32 sid;
>  	struct lsmblob blob;
>  
> -	security_task_getsecid(current, &sid);
> -	if (!sid)
> +	security_task_getsecid(current, &blob);
> +	if (!lsmblob_is_set(&blob))
>  		return 0;
>  
> -	lsmblob_init(&blob, sid);
>  	error = security_secid_to_secctx(&blob, &ctx, &len);
>  	if (error) {
>  		if (error != -EINVAL)
> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> index da211065160f..76b4c0ca4fd2 100644
> --- a/kernel/auditfilter.c
> +++ b/kernel/auditfilter.c
> @@ -1323,7 +1323,6 @@ int audit_filter(int msgtype, unsigned int listtype)
>  		for (i = 0; i < e->rule.field_count; i++) {
>  			struct audit_field *f = &e->rule.fields[i];
>  			pid_t pid;
> -			u32 sid;
>  			struct lsmblob blob;
>  
>  			switch (f->type) {
> @@ -1354,8 +1353,7 @@ int audit_filter(int msgtype, unsigned int listtype)
>  			case AUDIT_SUBJ_SEN:
>  			case AUDIT_SUBJ_CLR:
>  				if (f->lsm_rule) {
> -					security_task_getsecid(current, &sid);
> -					lsmblob_init(&blob, sid);
> +					security_task_getsecid(current, &blob);
>  					result = security_audit_rule_match(&blob,
>  						   f->type, f->op, f->lsm_rule);
>  				}
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 148733ec3c72..7112fe31684d 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -444,7 +444,6 @@ static int audit_filter_rules(struct task_struct *tsk,
>  {
>  	const struct cred *cred;
>  	int i, need_sid = 1;
> -	u32 sid;
>  	struct lsmblob blob;
>  	unsigned int sessionid;
>  
> @@ -628,10 +627,9 @@ static int audit_filter_rules(struct task_struct *tsk,
>  			   logged upon error */
>  			if (f->lsm_rule) {
>  				if (need_sid) {
> -					security_task_getsecid(tsk, &sid);
> +					security_task_getsecid(tsk, &blob);
>  					need_sid = 0;
>  				}
> -				lsmblob_init(&blob, sid);
>  				result = security_audit_rule_match(&blob,
>  								   f->type,
>  								   f->op,
> @@ -2365,12 +2363,15 @@ int __audit_sockaddr(int len, void *a)
>  void __audit_ptrace(struct task_struct *t)
>  {
>  	struct audit_context *context = audit_context();
> +	struct lsmblob blob;
>  
>  	context->target_pid = task_tgid_nr(t);
>  	context->target_auid = audit_get_loginuid(t);
>  	context->target_uid = task_uid(t);
>  	context->target_sessionid = audit_get_sessionid(t);
> -	security_task_getsecid(t, &context->target_sid);
> +	security_task_getsecid(t, &blob);
> +	/* scaffolding - until target_sid is converted */
> +	context->target_sid = blob.secid[0];
>  	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
>  }
>  
> @@ -2387,6 +2388,7 @@ int audit_signal_info(int sig, struct task_struct *t)
>  	struct audit_aux_data_pids *axp;
>  	struct audit_context *ctx = audit_context();
>  	kuid_t uid = current_uid(), auid, t_uid = task_uid(t);
> +	struct lsmblob blob;
>  
>  	if (auditd_test_task(t) &&
>  	    (sig == SIGTERM || sig == SIGHUP ||
> @@ -2397,7 +2399,9 @@ int audit_signal_info(int sig, struct task_struct *t)
>  			audit_sig_uid = auid;
>  		else
>  			audit_sig_uid = uid;
> -		security_task_getsecid(current, &audit_sig_sid);
> +		security_task_getsecid(current, &blob);
> +		/* scaffolding until audit_sig_sid is converted */
> +		audit_sig_sid = blob.secid[0];
>  	}
>  
>  	if (!audit_signals || audit_dummy_context())
> @@ -2410,7 +2414,9 @@ int audit_signal_info(int sig, struct task_struct *t)
>  		ctx->target_auid = audit_get_loginuid(t);
>  		ctx->target_uid = t_uid;
>  		ctx->target_sessionid = audit_get_sessionid(t);
> -		security_task_getsecid(t, &ctx->target_sid);
> +		security_task_getsecid(t, &blob);
> +		/* scaffolding until target_sid is converted */
> +		ctx->target_sid = blob.secid[0];
>  		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
>  		return 0;
>  	}
> @@ -2431,7 +2437,9 @@ int audit_signal_info(int sig, struct task_struct *t)
>  	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
>  	axp->target_uid[axp->pid_count] = t_uid;
>  	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
> -	security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
> +	security_task_getsecid(t, &blob);
> +	/* scaffolding until target_sid is converted */
> +	axp->target_sid[axp->pid_count] = blob.secid[0];
>  	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
>  	axp->pid_count++;
>  
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 2d8dd5b84457..2294aa9471e6 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -1552,11 +1552,14 @@ int __init netlbl_unlabel_defconf(void)
>  	int ret_val;
>  	struct netlbl_dom_map *entry;
>  	struct netlbl_audit audit_info;
> +	struct lsmblob blob;
>  
>  	/* Only the kernel is allowed to call this function and the only time
>  	 * it is called is at bootup before the audit subsystem is reporting
>  	 * messages so don't worry to much about these values. */
> -	security_task_getsecid(current, &audit_info.secid);
> +	security_task_getsecid(current, &blob);
> +	/* scaffolding until audit_info.secid is converted */
> +	audit_info.secid = blob.secid[0];
>  	audit_info.loginuid = GLOBAL_ROOT_UID;
>  	audit_info.sessionid = 0;
>  
> diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
> index 4a397cde1a48..ab88baaaa50d 100644
> --- a/net/netlabel/netlabel_user.h
> +++ b/net/netlabel/netlabel_user.h
> @@ -48,7 +48,11 @@
>  static inline void netlbl_netlink_auditinfo(struct sk_buff *skb,
>  					    struct netlbl_audit *audit_info)
>  {
> -	security_task_getsecid(current, &audit_info->secid);
> +	struct lsmblob blob;
> +
> +	security_task_getsecid(current, &blob);
> +	/* scaffolding until secid is converted */
> +	audit_info->secid = blob.secid[0];
>  	audit_info->loginuid = audit_get_loginuid(current);
>  	audit_info->sessionid = audit_get_sessionid(current);
>  }
> diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
> index 5fb7127bbe68..85c7692fc4a3 100644
> --- a/security/integrity/ima/ima_appraise.c
> +++ b/security/integrity/ima/ima_appraise.c
> @@ -51,11 +51,13 @@ bool is_ima_appraise_enabled(void)
>  int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
>  {
>  	u32 secid;
> +	struct lsmblob blob;
>  
>  	if (!ima_appraise)
>  		return 0;
>  
> -	security_task_getsecid(current, &secid);
> +	security_task_getsecid(current, &blob);
> +	lsmblob_secid(&blob, &secid);
>  	return ima_match_policy(inode, current_cred(), secid, func, mask,
>  				IMA_APPRAISE | IMA_HASH, NULL);
>  }
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 357edd140c09..fefa848cf0c7 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -335,12 +335,13 @@ static int process_measurement(struct file *file, const struct cred *cred,
>   */
>  int ima_file_mmap(struct file *file, unsigned long prot)
>  {
> -	u32 secid;
> +	struct lsmblob blob;
>  
>  	if (file && (prot & PROT_EXEC)) {
> -		security_task_getsecid(current, &secid);
> -		return process_measurement(file, current_cred(), secid, NULL,
> -					   0, MAY_EXEC, MMAP_CHECK);
> +		security_task_getsecid(current, &blob);
> +		/* scaffolding - until process_measurement changes */
> +		return process_measurement(file, current_cred(), blob.secid[0],
> +					   NULL, 0, MAY_EXEC, MMAP_CHECK);
>  	}
>  
>  	return 0;
> @@ -363,10 +364,12 @@ int ima_bprm_check(struct linux_binprm *bprm)
>  {
>  	int ret;
>  	u32 secid;
> +	struct lsmblob blob;
>  
> -	security_task_getsecid(current, &secid);
> -	ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0,
> -				  MAY_EXEC, BPRM_CHECK);
> +	security_task_getsecid(current, &blob);
> +	/* scaffolding until process_measurement changes */
> +	ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
> +				  NULL, 0, MAY_EXEC, BPRM_CHECK);
>  	if (ret)
>  		return ret;
>  
> @@ -387,10 +390,11 @@ int ima_bprm_check(struct linux_binprm *bprm)
>   */
>  int ima_file_check(struct file *file, int mask)
>  {
> -	u32 secid;
> +	struct lsmblob blob;
>  
> -	security_task_getsecid(current, &secid);
> -	return process_measurement(file, current_cred(), secid, NULL, 0,
> +	security_task_getsecid(current, &blob);
> +	/* scaffolding until process_measurement changes */
> +	return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
>  				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
>  					   MAY_APPEND), FILE_CHECK);
>  }
> @@ -499,7 +503,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
>  		       enum kernel_read_file_id read_id)
>  {
>  	enum ima_hooks func;
> -	u32 secid;
> +	struct lsmblob blob;
>  
>  	if (!file && read_id == READING_FIRMWARE) {
>  		if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
> @@ -521,9 +525,10 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
>  	}
>  
>  	func = read_idmap[read_id] ?: FILE_CHECK;
> -	security_task_getsecid(current, &secid);
> -	return process_measurement(file, current_cred(), secid, buf, size,
> -				   MAY_READ, func);
> +	security_task_getsecid(current, &blob);
> +	/* scaffolding until process_measurement changes */
> +	return process_measurement(file, current_cred(), blob.secid[0], buf,
> +				   size, MAY_READ, func);
>  }
>  
>  /**
> diff --git a/security/security.c b/security/security.c
> index d55f01041f05..1184ef092bce 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1729,10 +1729,13 @@ int security_task_getsid(struct task_struct *p)
>  	return call_int_hook(task_getsid, 0, p);
>  }
>  
> -void security_task_getsecid(struct task_struct *p, u32 *secid)
> +void security_task_getsecid(struct task_struct *p, struct lsmblob *blob)
>  {
> -	*secid = 0;
> -	call_void_hook(task_getsecid, p, secid);
> +	struct security_hook_list *hp;
> +
> +	lsmblob_init(blob, 0);
> +	hlist_for_each_entry(hp, &security_hook_heads.task_getsecid, list)
> +		hp->hook.task_getsecid(p, &blob->secid[hp->slot]);
>  }
>  EXPORT_SYMBOL(security_task_getsecid);
>  
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 12/24] LSM: Use lsmblob in security_inode_getsecid
  2019-06-21 18:52 ` [PATCH v3 12/24] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
@ 2019-06-22 22:49   ` Kees Cook
  2019-06-24 18:40   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:49 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:21AM -0700, Casey Schaufler wrote:
> Change the security_inode_getsecid() interface to fill in a
> lsmblob structure instead of a u32 secid. This allows for its
> callers to gather data from all registered LSMs. Data is provided
> for IMA and audit.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  include/linux/security.h            | 7 ++++---
>  kernel/auditsc.c                    | 6 +++++-
>  security/integrity/ima/ima_policy.c | 4 +---
>  security/security.c                 | 8 ++++++--
>  4 files changed, 16 insertions(+), 9 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index c5fdaaff8806..6eb64b7f878a 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -358,7 +358,7 @@ int security_inode_killpriv(struct dentry *dentry);
>  int security_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc);
>  int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags);
>  int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size);
> -void security_inode_getsecid(struct inode *inode, u32 *secid);
> +void security_inode_getsecid(struct inode *inode, struct lsmblob *blob);
>  int security_inode_copy_up(struct dentry *src, struct cred **new);
>  int security_inode_copy_up_xattr(const char *name);
>  int security_file_permission(struct file *file, int mask);
> @@ -854,9 +854,10 @@ static inline int security_inode_listsecurity(struct inode *inode, char *buffer,
>  	return 0;
>  }
>  
> -static inline void security_inode_getsecid(struct inode *inode, u32 *secid)
> +static inline void security_inode_getsecid(struct inode *inode,
> +					   struct lsmblob *blob)
>  {
> -	*secid = 0;
> +	lsmblob_init(blob, 0);
>  }
>  
>  static inline int security_inode_copy_up(struct dentry *src, struct cred **new)
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 7112fe31684d..54797c0fc3b7 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -1910,13 +1910,17 @@ static inline int audit_copy_fcaps(struct audit_names *name,
>  void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
>  		      struct inode *inode, unsigned int flags)
>  {
> +	struct lsmblob blob;
> +
>  	name->ino   = inode->i_ino;
>  	name->dev   = inode->i_sb->s_dev;
>  	name->mode  = inode->i_mode;
>  	name->uid   = inode->i_uid;
>  	name->gid   = inode->i_gid;
>  	name->rdev  = inode->i_rdev;
> -	security_inode_getsecid(inode, &name->osid);
> +	security_inode_getsecid(inode, &blob);
> +	/* scaffolding until osid is updated */
> +	name->osid = blob.secid[0];
>  	if (flags & AUDIT_INODE_NOEVAL) {
>  		name->fcap_ver = -1;
>  		return;
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index e7b8ce942950..92ee3d984c73 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -326,7 +326,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  		return false;
>  	for (i = 0; i < MAX_LSM_RULES; i++) {
>  		int rc = 0;
> -		u32 osid;
>  		struct lsmblob blob;
>  		int retried = 0;
>  
> @@ -337,8 +336,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  		case LSM_OBJ_USER:
>  		case LSM_OBJ_ROLE:
>  		case LSM_OBJ_TYPE:
> -			security_inode_getsecid(inode, &osid);
> -			lsmblob_init(&blob, osid);
> +			security_inode_getsecid(inode, &blob);
>  			rc = security_filter_rule_match(&blob,
>  							rule->lsm[i].type,
>  							Audit_equal,
> diff --git a/security/security.c b/security/security.c
> index 1184ef092bce..6f0635b51180 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1423,9 +1423,13 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer
>  }
>  EXPORT_SYMBOL(security_inode_listsecurity);
>  
> -void security_inode_getsecid(struct inode *inode, u32 *secid)
> +void security_inode_getsecid(struct inode *inode, struct lsmblob *blob)
>  {
> -	call_void_hook(inode_getsecid, inode, secid);
> +	struct security_hook_list *hp;
> +
> +	lsmblob_init(blob, 0);
> +	hlist_for_each_entry(hp, &security_hook_heads.inode_getsecid, list)
> +		hp->hook.inode_getsecid(inode, &blob->secid[hp->slot]);
>  }
>  
>  int security_inode_copy_up(struct dentry *src, struct cred **new)
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 13/24] LSM: Use lsmblob in security_cred_getsecid
  2019-06-21 18:52 ` [PATCH v3 13/24] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
@ 2019-06-22 22:50   ` Kees Cook
  2019-06-24 18:40   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:50 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:22AM -0700, Casey Schaufler wrote:
> Change the security_cred_getsecid() interface to fill in a
> lsmblob instead of a u32 secid. The associated data elements
> in the audit sub-system are changed from a secid to a lsmblob
> to accomodate multiple possible LSM audit users.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  include/linux/security.h          |  2 +-
>  kernel/audit.c                    | 14 +++++-------
>  kernel/audit.h                    |  5 +++--
>  kernel/auditsc.c                  | 37 +++++++++++--------------------
>  security/integrity/ima/ima_main.c |  8 +++----
>  security/security.c               |  9 +++++---
>  6 files changed, 33 insertions(+), 42 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 6eb64b7f878a..c712fc72b7bd 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -383,7 +383,7 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp);
>  void security_cred_free(struct cred *cred);
>  int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
>  void security_transfer_creds(struct cred *new, const struct cred *old);
> -void security_cred_getsecid(const struct cred *c, u32 *secid);
> +void security_cred_getsecid(const struct cred *c, struct lsmblob *blob);
>  int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
>  int security_kernel_create_files_as(struct cred *new, struct inode *inode);
>  int security_kernel_module_request(char *kmod_name);
> diff --git a/kernel/audit.c b/kernel/audit.c
> index a0205f3c23c7..1b51e907f131 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -137,7 +137,7 @@ static u32	audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
>  /* The identity of the user shutting down the audit system. */
>  kuid_t		audit_sig_uid = INVALID_UID;
>  pid_t		audit_sig_pid = -1;
> -u32		audit_sig_sid = 0;
> +struct lsmblob	audit_sig_lsm;
>  
>  /* Records can be lost in several ways:
>     0) [suppressed in audit_alloc]
> @@ -1429,23 +1429,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
>  	}
>  	case AUDIT_SIGNAL_INFO:
>  		len = 0;
> -		if (audit_sig_sid) {
> -			struct lsmblob blob;
> -
> -			lsmblob_init(&blob, audit_sig_sid);
> -			err = security_secid_to_secctx(&blob, &ctx, &len);
> +		if (lsmblob_is_set(&audit_sig_lsm)) {
> +			err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
> +						       &len);
>  			if (err)
>  				return err;
>  		}
>  		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
>  		if (!sig_data) {
> -			if (audit_sig_sid)
> +			if (lsmblob_is_set(&audit_sig_lsm))
>  				security_release_secctx(ctx, len);
>  			return -ENOMEM;
>  		}
>  		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
>  		sig_data->pid = audit_sig_pid;
> -		if (audit_sig_sid) {
> +		if (lsmblob_is_set(&audit_sig_lsm)) {
>  			memcpy(sig_data->ctx, ctx, len);
>  			security_release_secctx(ctx, len);
>  		}
> diff --git a/kernel/audit.h b/kernel/audit.h
> index 958d5b8fc1b3..29e29c6f4afb 100644
> --- a/kernel/audit.h
> +++ b/kernel/audit.h
> @@ -22,6 +22,7 @@
>  #include <linux/fs.h>
>  #include <linux/audit.h>
>  #include <linux/skbuff.h>
> +#include <linux/security.h>
>  #include <uapi/linux/mqueue.h>
>  #include <linux/tty.h>
>  
> @@ -147,7 +148,7 @@ struct audit_context {
>  	kuid_t		    target_auid;
>  	kuid_t		    target_uid;
>  	unsigned int	    target_sessionid;
> -	u32		    target_sid;
> +	struct lsmblob   target_lsm;
>  	char		    target_comm[TASK_COMM_LEN];
>  
>  	struct audit_tree_refs *trees, *first_trees;
> @@ -338,7 +339,7 @@ extern char *audit_unpack_string(void **bufp, size_t *remain, size_t len);
>  
>  extern pid_t audit_sig_pid;
>  extern kuid_t audit_sig_uid;
> -extern u32 audit_sig_sid;
> +extern struct lsmblob audit_sig_lsm;
>  
>  extern int audit_filter(int msgtype, unsigned int listtype);
>  
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 54797c0fc3b7..c7aa39bda5cc 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -112,7 +112,7 @@ struct audit_aux_data_pids {
>  	kuid_t			target_auid[AUDIT_AUX_PIDS];
>  	kuid_t			target_uid[AUDIT_AUX_PIDS];
>  	unsigned int		target_sessionid[AUDIT_AUX_PIDS];
> -	u32			target_sid[AUDIT_AUX_PIDS];
> +	struct lsmblob	target_lsm[AUDIT_AUX_PIDS];
>  	char 			target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
>  	int			pid_count;
>  };
> @@ -938,14 +938,14 @@ static inline void audit_free_context(struct audit_context *context)
>  }
>  
>  static int audit_log_pid_context(struct audit_context *context, pid_t pid,
> -				 kuid_t auid, kuid_t uid, unsigned int sessionid,
> -				 u32 sid, char *comm)
> +				 kuid_t auid, kuid_t uid,
> +				 unsigned int sessionid,
> +				 struct lsmblob *blob, char *comm)
>  {
>  	struct audit_buffer *ab;
>  	char *ctx = NULL;
>  	u32 len;
>  	int rc = 0;
> -	struct lsmblob blob;
>  
>  	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
>  	if (!ab)
> @@ -954,9 +954,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
>  			 from_kuid(&init_user_ns, auid),
>  			 from_kuid(&init_user_ns, uid), sessionid);
> -	if (sid) {
> -		lsmblob_init(&blob, sid);
> -		if (security_secid_to_secctx(&blob, &ctx, &len)) {
> +	if (lsmblob_is_set(blob)) {
> +		if (security_secid_to_secctx(blob, &ctx, &len)) {
>  			audit_log_format(ab, " obj=(none)");
>  			rc = 1;
>  		} else {
> @@ -1527,7 +1526,7 @@ static void audit_log_exit(void)
>  						  axs->target_auid[i],
>  						  axs->target_uid[i],
>  						  axs->target_sessionid[i],
> -						  axs->target_sid[i],
> +						  &axs->target_lsm[i],
>  						  axs->target_comm[i]))
>  				call_panic = 1;
>  	}
> @@ -1536,7 +1535,7 @@ static void audit_log_exit(void)
>  	    audit_log_pid_context(context, context->target_pid,
>  				  context->target_auid, context->target_uid,
>  				  context->target_sessionid,
> -				  context->target_sid, context->target_comm))
> +				  &context->target_lsm, context->target_comm))
>  			call_panic = 1;
>  
>  	if (context->pwd.dentry && context->pwd.mnt) {
> @@ -1713,7 +1712,7 @@ void __audit_syscall_exit(int success, long return_code)
>  	context->aux = NULL;
>  	context->aux_pids = NULL;
>  	context->target_pid = 0;
> -	context->target_sid = 0;
> +	lsmblob_init(&context->target_lsm, 0);
>  	context->sockaddr_len = 0;
>  	context->type = 0;
>  	context->fds[0] = -1;
> @@ -2367,15 +2366,12 @@ int __audit_sockaddr(int len, void *a)
>  void __audit_ptrace(struct task_struct *t)
>  {
>  	struct audit_context *context = audit_context();
> -	struct lsmblob blob;
>  
>  	context->target_pid = task_tgid_nr(t);
>  	context->target_auid = audit_get_loginuid(t);
>  	context->target_uid = task_uid(t);
>  	context->target_sessionid = audit_get_sessionid(t);
> -	security_task_getsecid(t, &blob);
> -	/* scaffolding - until target_sid is converted */
> -	context->target_sid = blob.secid[0];
> +	security_task_getsecid(t, &context->target_lsm);
>  	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
>  }
>  
> @@ -2392,7 +2388,6 @@ int audit_signal_info(int sig, struct task_struct *t)
>  	struct audit_aux_data_pids *axp;
>  	struct audit_context *ctx = audit_context();
>  	kuid_t uid = current_uid(), auid, t_uid = task_uid(t);
> -	struct lsmblob blob;
>  
>  	if (auditd_test_task(t) &&
>  	    (sig == SIGTERM || sig == SIGHUP ||
> @@ -2403,9 +2398,7 @@ int audit_signal_info(int sig, struct task_struct *t)
>  			audit_sig_uid = auid;
>  		else
>  			audit_sig_uid = uid;
> -		security_task_getsecid(current, &blob);
> -		/* scaffolding until audit_sig_sid is converted */
> -		audit_sig_sid = blob.secid[0];
> +		security_task_getsecid(current, &audit_sig_lsm);
>  	}
>  
>  	if (!audit_signals || audit_dummy_context())
> @@ -2418,9 +2411,7 @@ int audit_signal_info(int sig, struct task_struct *t)
>  		ctx->target_auid = audit_get_loginuid(t);
>  		ctx->target_uid = t_uid;
>  		ctx->target_sessionid = audit_get_sessionid(t);
> -		security_task_getsecid(t, &blob);
> -		/* scaffolding until target_sid is converted */
> -		ctx->target_sid = blob.secid[0];
> +		security_task_getsecid(t, &ctx->target_lsm);
>  		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
>  		return 0;
>  	}
> @@ -2441,9 +2432,7 @@ int audit_signal_info(int sig, struct task_struct *t)
>  	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
>  	axp->target_uid[axp->pid_count] = t_uid;
>  	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
> -	security_task_getsecid(t, &blob);
> -	/* scaffolding until target_sid is converted */
> -	axp->target_sid[axp->pid_count] = blob.secid[0];
> +	security_task_getsecid(t, &axp->target_lsm[axp->pid_count]);
>  	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
>  	axp->pid_count++;
>  
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index fefa848cf0c7..1afb75a893af 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -363,7 +363,6 @@ int ima_file_mmap(struct file *file, unsigned long prot)
>  int ima_bprm_check(struct linux_binprm *bprm)
>  {
>  	int ret;
> -	u32 secid;
>  	struct lsmblob blob;
>  
>  	security_task_getsecid(current, &blob);
> @@ -373,9 +372,10 @@ int ima_bprm_check(struct linux_binprm *bprm)
>  	if (ret)
>  		return ret;
>  
> -	security_cred_getsecid(bprm->cred, &secid);
> -	return process_measurement(bprm->file, bprm->cred, secid, NULL, 0,
> -				   MAY_EXEC, CREDS_CHECK);
> +	security_cred_getsecid(bprm->cred, &blob);
> +	/* scaffolding until process_measurement changes */
> +	return process_measurement(bprm->file, bprm->cred, blob.secid[0],
> +				   NULL, 0, MAY_EXEC, CREDS_CHECK);
>  }
>  
>  /**
> diff --git a/security/security.c b/security/security.c
> index 6f0635b51180..aa8e1c73a062 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1643,10 +1643,13 @@ void security_transfer_creds(struct cred *new, const struct cred *old)
>  	call_void_hook(cred_transfer, new, old);
>  }
>  
> -void security_cred_getsecid(const struct cred *c, u32 *secid)
> +void security_cred_getsecid(const struct cred *c, struct lsmblob *blob)
>  {
> -	*secid = 0;
> -	call_void_hook(cred_getsecid, c, secid);
> +	struct security_hook_list *hp;
> +
> +	lsmblob_init(blob, 0);
> +	hlist_for_each_entry(hp, &security_hook_heads.cred_getsecid, list)
> +		hp->hook.cred_getsecid(c, &blob->secid[hp->slot]);
>  }
>  EXPORT_SYMBOL(security_cred_getsecid);
>  
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 14/24] IMA: Change internal interfaces to use lsmblobs
  2019-06-21 18:52 ` [PATCH v3 14/24] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
@ 2019-06-22 22:51   ` Kees Cook
  2019-06-24 18:40   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:51 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:23AM -0700, Casey Schaufler wrote:
> The IMA interfaces ima_get_action() and ima_match_policy()
> call LSM functions that use lsmblobs. Change the IMA functions
> to pass the lsmblob to be compatible with the LSM functions.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---
>  security/integrity/ima/ima.h          | 10 ++++++----
>  security/integrity/ima/ima_api.c      |  9 +++++----
>  security/integrity/ima/ima_appraise.c |  4 +---
>  security/integrity/ima/ima_main.c     | 27 +++++++++++----------------
>  security/integrity/ima/ima_policy.c   | 12 ++++++------
>  5 files changed, 29 insertions(+), 33 deletions(-)
> 
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index 5a337239d9e4..73b3b15dec5c 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -192,8 +192,9 @@ enum ima_hooks {
>  };
>  
>  /* LIM API function definitions */
> -int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
> -		   int mask, enum ima_hooks func, int *pcr);
> +int ima_get_action(struct inode *inode, const struct cred *cred,
> +		   struct lsmblob *blob, int mask, enum ima_hooks func,
> +		   int *pcr);
>  int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
>  int ima_collect_measurement(struct integrity_iint_cache *iint,
>  			    struct file *file, void *buf, loff_t size,
> @@ -213,8 +214,9 @@ void ima_free_template_entry(struct ima_template_entry *entry);
>  const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
>  
>  /* IMA policy related functions */
> -int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
> -		     enum ima_hooks func, int mask, int flags, int *pcr);
> +int ima_match_policy(struct inode *inode, const struct cred *cred,
> +		     struct lsmblob *blob, enum ima_hooks func, int mask,
> +		     int flags, int *pcr);
>  void ima_init_policy(void);
>  void ima_update_policy(void);
>  void ima_update_policy_flag(void);
> diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
> index c7505fb122d4..03a2392852de 100644
> --- a/security/integrity/ima/ima_api.c
> +++ b/security/integrity/ima/ima_api.c
> @@ -159,7 +159,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
>   * ima_get_action - appraise & measure decision based on policy.
>   * @inode: pointer to inode to measure
>   * @cred: pointer to credentials structure to validate
> - * @secid: secid of the task being validated
> + * @blob: LAM data of the task being validated

typo: LAM -> LSM

with that fixed:

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

>   * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC,
>   *        MAY_APPEND)
>   * @func: caller identifier
> @@ -175,14 +175,15 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
>   * Returns IMA_MEASURE, IMA_APPRAISE mask.
>   *
>   */
> -int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
> -		   int mask, enum ima_hooks func, int *pcr)
> +int ima_get_action(struct inode *inode, const struct cred *cred,
> +		   struct lsmblob *blob, int mask, enum ima_hooks func,
> +		   int *pcr)
>  {
>  	int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH;
>  
>  	flags &= ima_policy_flag;
>  
> -	return ima_match_policy(inode, cred, secid, func, mask, flags, pcr);
> +	return ima_match_policy(inode, cred, blob, func, mask, flags, pcr);
>  }
>  
>  /*
> diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
> index 85c7692fc4a3..3ff7aae81829 100644
> --- a/security/integrity/ima/ima_appraise.c
> +++ b/security/integrity/ima/ima_appraise.c
> @@ -50,15 +50,13 @@ bool is_ima_appraise_enabled(void)
>   */
>  int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
>  {
> -	u32 secid;
>  	struct lsmblob blob;
>  
>  	if (!ima_appraise)
>  		return 0;
>  
>  	security_task_getsecid(current, &blob);
> -	lsmblob_secid(&blob, &secid);
> -	return ima_match_policy(inode, current_cred(), secid, func, mask,
> +	return ima_match_policy(inode, current_cred(), &blob, func, mask,
>  				IMA_APPRAISE | IMA_HASH, NULL);
>  }
>  
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 1afb75a893af..0588dd9a88db 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -169,8 +169,8 @@ void ima_file_free(struct file *file)
>  }
>  
>  static int process_measurement(struct file *file, const struct cred *cred,
> -			       u32 secid, char *buf, loff_t size, int mask,
> -			       enum ima_hooks func)
> +			       struct lsmblob *blob, char *buf, loff_t size,
> +			       int mask, enum ima_hooks func)
>  {
>  	struct inode *inode = file_inode(file);
>  	struct integrity_iint_cache *iint = NULL;
> @@ -192,7 +192,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
>  	 * bitmask based on the appraise/audit/measurement policy.
>  	 * Included is the appraise submask.
>  	 */
> -	action = ima_get_action(inode, cred, secid, mask, func, &pcr);
> +	action = ima_get_action(inode, cred, blob, mask, func, &pcr);
>  	violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
>  			   (ima_policy_flag & IMA_MEASURE));
>  	if (!action && !violation_check)
> @@ -339,8 +339,7 @@ int ima_file_mmap(struct file *file, unsigned long prot)
>  
>  	if (file && (prot & PROT_EXEC)) {
>  		security_task_getsecid(current, &blob);
> -		/* scaffolding - until process_measurement changes */
> -		return process_measurement(file, current_cred(), blob.secid[0],
> +		return process_measurement(file, current_cred(), &blob,
>  					   NULL, 0, MAY_EXEC, MMAP_CHECK);
>  	}
>  
> @@ -366,16 +365,14 @@ int ima_bprm_check(struct linux_binprm *bprm)
>  	struct lsmblob blob;
>  
>  	security_task_getsecid(current, &blob);
> -	/* scaffolding until process_measurement changes */
> -	ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
> -				  NULL, 0, MAY_EXEC, BPRM_CHECK);
> +	ret = process_measurement(bprm->file, current_cred(), &blob, NULL, 0,
> +				  MAY_EXEC, BPRM_CHECK);
>  	if (ret)
>  		return ret;
>  
>  	security_cred_getsecid(bprm->cred, &blob);
> -	/* scaffolding until process_measurement changes */
> -	return process_measurement(bprm->file, bprm->cred, blob.secid[0],
> -				   NULL, 0, MAY_EXEC, CREDS_CHECK);
> +	return process_measurement(bprm->file, bprm->cred, &blob, NULL, 0,
> +				   MAY_EXEC, CREDS_CHECK);
>  }
>  
>  /**
> @@ -393,8 +390,7 @@ int ima_file_check(struct file *file, int mask)
>  	struct lsmblob blob;
>  
>  	security_task_getsecid(current, &blob);
> -	/* scaffolding until process_measurement changes */
> -	return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
> +	return process_measurement(file, current_cred(), &blob, NULL, 0,
>  				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
>  					   MAY_APPEND), FILE_CHECK);
>  }
> @@ -526,9 +522,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
>  
>  	func = read_idmap[read_id] ?: FILE_CHECK;
>  	security_task_getsecid(current, &blob);
> -	/* scaffolding until process_measurement changes */
> -	return process_measurement(file, current_cred(), blob.secid[0], buf,
> -				   size, MAY_READ, func);
> +	return process_measurement(file, current_cred(), &blob, buf, size,
> +				   MAY_READ, func);
>  }
>  
>  /**
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index 92ee3d984c73..dbad256aa7b4 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -286,7 +286,7 @@ static void ima_lsm_update_rules(void)
>   * Returns true on rule match, false on failure.
>   */
>  static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
> -			    const struct cred *cred, u32 secid,
> +			    const struct cred *cred, struct lsmblob *blob,
>  			    enum ima_hooks func, int mask)
>  {
>  	int i;
> @@ -345,7 +345,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  		case LSM_SUBJ_USER:
>  		case LSM_SUBJ_ROLE:
>  		case LSM_SUBJ_TYPE:
> -			lsmblob_init(&blob, secid);
>  			rc = security_filter_rule_match(&blob,
>  							rule->lsm[i].type,
>  							Audit_equal,
> @@ -394,7 +393,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
>   * @inode: pointer to an inode for which the policy decision is being made
>   * @cred: pointer to a credentials structure for which the policy decision is
>   *        being made
> - * @secid: LSM secid of the task to be validated
> + * @blob: LSM data of the task to be validated
>   * @func: IMA hook identifier
>   * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
>   * @pcr: set the pcr to extend
> @@ -406,8 +405,9 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
>   * list when walking it.  Reads are many orders of magnitude more numerous
>   * than writes so ima_match_policy() is classical RCU candidate.
>   */
> -int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
> -		     enum ima_hooks func, int mask, int flags, int *pcr)
> +int ima_match_policy(struct inode *inode, const struct cred *cred,
> +		     struct lsmblob *blob, enum ima_hooks func, int mask,
> +		     int flags, int *pcr)
>  {
>  	struct ima_rule_entry *entry;
>  	int action = 0, actmask = flags | (flags << 1);
> @@ -418,7 +418,7 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
>  		if (!(entry->action & actmask))
>  			continue;
>  
> -		if (!ima_match_rules(entry, inode, cred, secid, func, mask))
> +		if (!ima_match_rules(entry, inode, cred, blob, func, mask))
>  			continue;
>  
>  		action |= entry->flags & IMA_ACTION_FLAGS;
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 15/24] LSM: Specify which LSM to display
  2019-06-21 18:52 ` [PATCH v3 15/24] LSM: Specify which LSM to display Casey Schaufler
@ 2019-06-22 22:51   ` Kees Cook
  2019-06-24 18:48   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:51 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:24AM -0700, Casey Schaufler wrote:
> Create a new entry "display" in /proc/.../attr for controlling
> which LSM security information is displayed for a process.
> The name of an active LSM that supplies hooks for human readable
> data may be written to "display" to set the value. The name of
> the LSM currently in use can be read from "display".
> At this point there can only be one LSM capable of display
> active.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  fs/proc/base.c      |   1 +
>  security/security.c | 110 +++++++++++++++++++++++++++++++++++---------
>  2 files changed, 90 insertions(+), 21 deletions(-)
> 
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index ddef482f1334..7bf70e041315 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -2618,6 +2618,7 @@ static const struct pid_entry attr_dir_stuff[] = {
>  	ATTR(NULL, "fscreate",		0666),
>  	ATTR(NULL, "keycreate",		0666),
>  	ATTR(NULL, "sockcreate",	0666),
> +	ATTR(NULL, "display",		0666),
>  #ifdef CONFIG_SECURITY_SMACK
>  	DIR("smack",			0555,
>  	    proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
> diff --git a/security/security.c b/security/security.c
> index aa8e1c73a062..92c5aa427b53 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -46,7 +46,9 @@ static struct kmem_cache *lsm_file_cache;
>  static struct kmem_cache *lsm_inode_cache;
>  
>  char *lsm_names;
> -static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init;
> +static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init = {
> +	.lbs_task = sizeof(int),	/* slot number for the "display" LSM */
> +};
>  
>  /* Boot-time LSM user choice */
>  static __initdata const char *chosen_lsm_order;
> @@ -583,6 +585,8 @@ int lsm_inode_alloc(struct inode *inode)
>   */
>  static int lsm_task_alloc(struct task_struct *task)
>  {
> +	int *display;
> +
>  	if (blob_sizes.lbs_task == 0) {
>  		task->security = NULL;
>  		return 0;
> @@ -591,6 +595,15 @@ static int lsm_task_alloc(struct task_struct *task)
>  	task->security = kzalloc(blob_sizes.lbs_task, GFP_KERNEL);
>  	if (task->security == NULL)
>  		return -ENOMEM;
> +
> +	/*
> +	 * The start of the task blob contains the "display" LSM slot number.
> +	 * Start with it set to the invalid slot number, indicating that the
> +	 * default first registered LSM be displayed.
> +	 */
> +	display = task->security;
> +	*display = LSMBLOB_INVALID;
> +
>  	return 0;
>  }
>  
> @@ -1579,14 +1592,24 @@ int security_file_open(struct file *file)
>  
>  int security_task_alloc(struct task_struct *task, unsigned long clone_flags)
>  {
> +	int *odisplay = current->security;
> +	int *ndisplay;
>  	int rc = lsm_task_alloc(task);
>  
> -	if (rc)
> +	if (unlikely(rc))
>  		return rc;
> +
>  	rc = call_int_hook(task_alloc, 0, task, clone_flags);
> -	if (unlikely(rc))
> +	if (unlikely(rc)) {
>  		security_task_free(task);
> -	return rc;
> +		return rc;
> +	}
> +
> +	ndisplay = task->security;
> +	if (ndisplay && odisplay)
> +		*ndisplay = *odisplay;
> +
> +	return 0;
>  }
>  
>  void security_task_free(struct task_struct *task)
> @@ -1972,10 +1995,28 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
>  				char **value)
>  {
>  	struct security_hook_list *hp;
> +	int *display = current->security;
> +
> +	if (!strcmp(name, "display")) {
> +		hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx,
> +				     list) {
> +			if (*display == LSMBLOB_INVALID ||
> +			    hp->slot == *display) {
> +				*value = kstrdup(hp->lsm, GFP_KERNEL);
> +				if (*value)
> +					return strlen(hp->lsm);
> +				return -ENOMEM;
> +			}
> +		}
> +		return -EINVAL;
> +	}
>  
>  	hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
>  		if (lsm != NULL && strcmp(lsm, hp->lsm))
>  			continue;
> +		if (lsm == NULL && *display != LSMBLOB_INVALID &&
> +		    *display != hp->slot)
> +			continue;
>  		return hp->hook.getprocattr(p, name, value);
>  	}
>  	return -EINVAL;
> @@ -1985,10 +2026,27 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>  			 size_t size)
>  {
>  	struct security_hook_list *hp;
> +	int *display = current->security;
> +	int len;
> +
> +	if (!strcmp(name, "display")) {
> +		hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx,
> +				     list) {
> +			len = strlen(hp->lsm);
> +			if (size >= len && !strncmp(value, hp->lsm, len)) {
> +				*display = hp->slot;
> +				return size;
> +			}
> +		}
> +		return -EINVAL;
> +	}
>  
>  	hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
>  		if (lsm != NULL && strcmp(lsm, hp->lsm))
>  			continue;
> +		if (lsm == NULL && *display != LSMBLOB_INVALID &&
> +		    *display != hp->slot)
> +			continue;
>  		return hp->hook.setprocattr(name, value, size);
>  	}
>  	return -EINVAL;
> @@ -2008,14 +2066,12 @@ EXPORT_SYMBOL(security_ismaclabel);
>  int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
>  {
>  	struct security_hook_list *hp;
> -	int rc;
> +	int *display = current->security;
>  
> -	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
> -		rc = hp->hook.secid_to_secctx(blob->secid[hp->slot],
> -					      secdata, seclen);
> -		if (rc != 0)
> -			return rc;
> -	}
> +	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list)
> +		if (*display == LSMBLOB_INVALID || *display == hp->slot)
> +			return hp->hook.secid_to_secctx(blob->secid[hp->slot],
> +							secdata, seclen);
>  	return 0;
>  }
>  EXPORT_SYMBOL(security_secid_to_secctx);
> @@ -2024,22 +2080,27 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
>  			     struct lsmblob *blob)
>  {
>  	struct security_hook_list *hp;
> -	int rc;
> +	int *display = current->security;
>  
>  	lsmblob_init(blob, 0);
> -	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
> -		rc = hp->hook.secctx_to_secid(secdata, seclen,
> -					      &blob->secid[hp->slot]);
> -		if (rc != 0)
> -			return rc;
> -	}
> +	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list)
> +		if (*display == LSMBLOB_INVALID || *display == hp->slot)
> +			return hp->hook.secctx_to_secid(secdata, seclen,
> +							&blob->secid[hp->slot]);
>  	return 0;
>  }
>  EXPORT_SYMBOL(security_secctx_to_secid);
>  
>  void security_release_secctx(char *secdata, u32 seclen)
>  {
> -	call_void_hook(release_secctx, secdata, seclen);
> +	struct security_hook_list *hp;
> +	int *display = current->security;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
> +		if (*display == LSMBLOB_INVALID || *display == hp->slot) {
> +			hp->hook.release_secctx(secdata, seclen);
> +			return;
> +		}
>  }
>  EXPORT_SYMBOL(security_release_secctx);
>  
> @@ -2164,8 +2225,15 @@ EXPORT_SYMBOL(security_sock_rcv_skb);
>  int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
>  				      int __user *optlen, unsigned len)
>  {
> -	return call_int_hook(socket_getpeersec_stream, -ENOPROTOOPT, sock,
> -				optval, optlen, len);
> +	int *display = current->security;
> +	struct security_hook_list *hp;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_stream,
> +			     list)
> +		if (*display == LSMBLOB_INVALID || *display == hp->slot)
> +			return hp->hook.socket_getpeersec_stream(sock, optval,
> +								 optlen, len);
> +	return -ENOPROTOOPT;
>  }
>  
>  int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 16/24] LSM: Ensure the correct LSM context releaser
  2019-06-21 18:52 ` [PATCH v3 16/24] LSM: Ensure the correct LSM context releaser Casey Schaufler
@ 2019-06-22 22:52   ` Kees Cook
  2019-06-24 21:46   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:52 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:25AM -0700, Casey Schaufler wrote:
> Add a new lsmcontext data structure to hold all the information
> about a "security context", including the string, its size and
> which LSM allocated the string. The allocation information is
> necessary because LSMs have different policies regarding the
> lifecycle of these strings. SELinux allocates and destroys
> them on each use, whereas Smack provides a pointer to an entry
> in a list that never goes away.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  drivers/android/binder.c                | 10 +++++--
>  fs/kernfs/dir.c                         |  9 ++++--
>  fs/kernfs/inode.c                       |  7 +++--
>  fs/nfs/nfs4proc.c                       |  8 +++--
>  fs/nfsd/nfs4xdr.c                       |  7 +++--
>  include/linux/security.h                | 39 +++++++++++++++++++++++--
>  include/net/scm.h                       |  4 ++-
>  kernel/audit.c                          | 14 ++++++---
>  kernel/auditsc.c                        | 12 ++++++--
>  net/ipv4/ip_sockglue.c                  |  4 ++-
>  net/netfilter/nf_conntrack_netlink.c    |  4 ++-
>  net/netfilter/nf_conntrack_standalone.c |  4 ++-
>  net/netfilter/nfnetlink_queue.c         | 13 ++++++---
>  net/netlabel/netlabel_unlabeled.c       | 19 +++++++++---
>  net/netlabel/netlabel_user.c            |  4 ++-
>  security/security.c                     | 12 +++++---
>  security/smack/smack_lsm.c              | 14 ++++++---
>  17 files changed, 142 insertions(+), 42 deletions(-)
> 
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 144ac4f1c24f..89e574be34cc 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -2876,6 +2876,7 @@ static void binder_transaction(struct binder_proc *proc,
>  	int t_debug_id = atomic_inc_return(&binder_last_id);
>  	char *secctx = NULL;
>  	u32 secctx_sz = 0;
> +	struct lsmcontext scaff; /* scaffolding */
>  
>  	e = binder_transaction_log_add(&binder_transaction_log);
>  	e->debug_id = t_debug_id;
> @@ -3158,7 +3159,8 @@ static void binder_transaction(struct binder_proc *proc,
>  		binder_alloc_copy_to_buffer(&target_proc->alloc,
>  					    t->buffer, buf_offset,
>  					    secctx, secctx_sz);
> -		security_release_secctx(secctx, secctx_sz);
> +		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
> +		security_release_secctx(&scaff);
>  		secctx = NULL;
>  	}
>  	t->buffer->debug_id = t->debug_id;
> @@ -3479,8 +3481,10 @@ static void binder_transaction(struct binder_proc *proc,
>  	t->buffer->transaction = NULL;
>  	binder_alloc_free_buf(&target_proc->alloc, t->buffer);
>  err_binder_alloc_buf_failed:
> -	if (secctx)
> -		security_release_secctx(secctx, secctx_sz);
> +	if (secctx) {
> +		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
> +		security_release_secctx(&scaff);
> +	}
>  err_get_secctx_failed:
>  	kfree(tcomplete);
>  	binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
> diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
> index b84d635567d3..92afad387237 100644
> --- a/fs/kernfs/dir.c
> +++ b/fs/kernfs/dir.c
> @@ -532,9 +532,12 @@ void kernfs_put(struct kernfs_node *kn)
>  	kfree_const(kn->name);
>  
>  	if (kn->iattr) {
> -		if (kn->iattr->ia_secdata)
> -			security_release_secctx(kn->iattr->ia_secdata,
> -						kn->iattr->ia_secdata_len);
> +		struct lsmcontext scaff; /* scaffolding */
> +		if (kn->iattr->ia_secdata) {
> +			lsmcontext_init(&scaff, kn->iattr->ia_secdata,
> +					kn->iattr->ia_secdata_len, 0);
> +			security_release_secctx(&scaff);
> +		}
>  		simple_xattrs_free(&kn->iattr->xattrs);
>  		kmem_cache_free(kernfs_iattrs_cache, kn->iattr);
>  	}
> diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
> index 0c1fd945ce42..02cde9dac5ee 100644
> --- a/fs/kernfs/inode.c
> +++ b/fs/kernfs/inode.c
> @@ -349,6 +349,7 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler,
>  {
>  	struct kernfs_node *kn = inode->i_private;
>  	struct kernfs_iattrs *attrs;
> +	struct lsmcontext context;
>  	void *secdata;
>  	u32 secdata_len = 0;
>  	int error;
> @@ -368,8 +369,10 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler,
>  	error = kernfs_node_setsecdata(attrs, &secdata, &secdata_len);
>  	mutex_unlock(&kernfs_mutex);
>  
> -	if (secdata)
> -		security_release_secctx(secdata, secdata_len);
> +	if (secdata) {
> +		lsmcontext_init(&context, secdata, secdata_len, 0);
> +		security_release_secctx(&context);
> +	}
>  	return error;
>  }
>  
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 4dbb0ee23432..af1c0db29c39 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -131,8 +131,12 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
>  static inline void
>  nfs4_label_release_security(struct nfs4_label *label)
>  {
> -	if (label)
> -		security_release_secctx(label->label, label->len);
> +	struct lsmcontext scaff; /* scaffolding */
> +
> +	if (label) {
> +		lsmcontext_init(&scaff, label->label, label->len, 0);
> +		security_release_secctx(&scaff);
> +	}
>  }
>  static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label)
>  {
> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index 3de42a729093..bb3db033e144 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -2420,6 +2420,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
>  	__be32 status;
>  	int err;
>  	struct nfs4_acl *acl = NULL;
> +	struct lsmcontext scaff; /* scaffolding */
>  	void *context = NULL;
>  	int contextlen;
>  	bool contextsupport = false;
> @@ -2919,8 +2920,10 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
>  
>  out:
>  #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
> -	if (context)
> -		security_release_secctx(context, contextlen);
> +	if (context) {
> +		lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/
> +		security_release_secctx(&scaff);
> +	}
>  #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
>  	kfree(acl);
>  	if (tempfh) {
> diff --git a/include/linux/security.h b/include/linux/security.h
> index c712fc72b7bd..ddf6d7cb23f1 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -76,6 +76,41 @@ enum lsm_event {
>  	LSM_POLICY_CHANGE,
>  };
>  
> +/*
> + * A "security context" is the text representation of
> + * the information used by LSMs.
> + * This structure contains the string, its length, and which LSM
> + * it is useful for.
> + */
> +struct lsmcontext {
> +	char	*context;	/* Provided by the module */
> +	u32	len;
> +	int	slot;		/* Identifies the module */
> +};
> +
> +/**
> + * lsmcontext_init - initialize an lsmcontext structure.
> + * @cp: Pointer to the context to initialize
> + * @context: Initial context, or NULL
> + * @size: Size of context, or 0
> + * @slot: Which LSM provided the context
> + *
> + * Fill in the lsmcontext from the provided information.
> + * This is a scaffolding function that will be removed when
> + * lsmcontext integration is complete.
> + */
> +static inline void lsmcontext_init(struct lsmcontext *cp, char *context,
> +				   u32 size, int slot)
> +{
> +	cp->slot = slot;
> +	cp->context = context;
> +
> +	if (context == NULL || size == 0)
> +		cp->len = 0;
> +	else
> +		cp->len = strlen(context);
> +}
> +
>  /*
>   * Data exported by the security modules
>   */
> @@ -445,7 +480,7 @@ int security_ismaclabel(const char *name);
>  int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
>  int security_secctx_to_secid(const char *secdata, u32 seclen,
>  			     struct lsmblob *blob);
> -void security_release_secctx(char *secdata, u32 seclen);
> +void security_release_secctx(struct lsmcontext *cp);
>  
>  void security_inode_invalidate_secctx(struct inode *inode);
>  int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
> @@ -1236,7 +1271,7 @@ static inline int security_secctx_to_secid(const char *secdata,
>  	return -EOPNOTSUPP;
>  }
>  
> -static inline void security_release_secctx(char *secdata, u32 seclen)
> +static inline void security_release_secctx(struct lsmcontext *cp)
>  {
>  }
>  
> diff --git a/include/net/scm.h b/include/net/scm.h
> index 31ae605fcc0a..6c7c3c229e4a 100644
> --- a/include/net/scm.h
> +++ b/include/net/scm.h
> @@ -92,6 +92,7 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
>  #ifdef CONFIG_SECURITY_NETWORK
>  static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
>  {
> +	struct lsmcontext context;
>  	char *secdata;
>  	u32 seclen;
>  	int err;
> @@ -102,7 +103,8 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
>  
>  		if (!err) {
>  			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
> -			security_release_secctx(secdata, seclen);
> +			lsmcontext_init(&context, secdata, seclen, 0);/*scaffolding*/
> +			security_release_secctx(&context);
>  		}
>  	}
>  }
> diff --git a/kernel/audit.c b/kernel/audit.c
> index 1b51e907f131..f844a2a642e6 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -1193,6 +1193,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
>  	struct audit_sig_info   *sig_data;
>  	char			*ctx = NULL;
>  	u32			len;
> +	struct lsmcontext	scaff; /* scaffolding */
>  
>  	err = audit_netlink_ok(skb, msg_type);
>  	if (err)
> @@ -1437,15 +1438,18 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
>  		}
>  		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
>  		if (!sig_data) {
> -			if (lsmblob_is_set(&audit_sig_lsm))
> -				security_release_secctx(ctx, len);
> +			if (lsmblob_is_set(&audit_sig_lsm)) {
> +				lsmcontext_init(&scaff, ctx, len, 0);
> +				security_release_secctx(&scaff);
> +			}
>  			return -ENOMEM;
>  		}
>  		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
>  		sig_data->pid = audit_sig_pid;
>  		if (lsmblob_is_set(&audit_sig_lsm)) {
>  			memcpy(sig_data->ctx, ctx, len);
> -			security_release_secctx(ctx, len);
> +			lsmcontext_init(&scaff, ctx, len, 0);
> +			security_release_secctx(&scaff);
>  		}
>  		audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
>  				 sig_data, sizeof(*sig_data) + len);
> @@ -2074,6 +2078,7 @@ int audit_log_task_context(struct audit_buffer *ab)
>  	unsigned len;
>  	int error;
>  	struct lsmblob blob;
> +	struct lsmcontext scaff; /* scaffolding */
>  
>  	security_task_getsecid(current, &blob);
>  	if (!lsmblob_is_set(&blob))
> @@ -2087,7 +2092,8 @@ int audit_log_task_context(struct audit_buffer *ab)
>  	}
>  
>  	audit_log_format(ab, " subj=%s", ctx);
> -	security_release_secctx(ctx, len);
> +	lsmcontext_init(&scaff, ctx, len, 0);
> +	security_release_secctx(&scaff);
>  	return 0;
>  
>  error_path:
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index c7aa39bda5cc..9fab0e7d90c3 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -943,6 +943,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  				 struct lsmblob *blob, char *comm)
>  {
>  	struct audit_buffer *ab;
> +	struct lsmcontext lsmcxt;
>  	char *ctx = NULL;
>  	u32 len;
>  	int rc = 0;
> @@ -960,7 +961,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  			rc = 1;
>  		} else {
>  			audit_log_format(ab, " obj=%s", ctx);
> -			security_release_secctx(ctx, len);
> +			lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/
> +			security_release_secctx(&lsmcxt);
>  		}
>  	}
>  	audit_log_format(ab, " ocomm=");
> @@ -1172,6 +1174,7 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
>  
>  static void show_special(struct audit_context *context, int *call_panic)
>  {
> +	struct lsmcontext lsmcxt;
>  	struct audit_buffer *ab;
>  	int i;
>  
> @@ -1205,7 +1208,8 @@ static void show_special(struct audit_context *context, int *call_panic)
>  				*call_panic = 1;
>  			} else {
>  				audit_log_format(ab, " obj=%s", ctx);
> -				security_release_secctx(ctx, len);
> +				lsmcontext_init(&lsmcxt, ctx, len, 0);
> +				security_release_secctx(&lsmcxt);
>  			}
>  		}
>  		if (context->ipc.has_perm) {
> @@ -1352,6 +1356,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
>  		char *ctx = NULL;
>  		u32 len;
>  		struct lsmblob blob;
> +		struct lsmcontext lsmcxt;
>  
>  		lsmblob_init(&blob, n->osid);
>  		if (security_secid_to_secctx(&blob, &ctx, &len)) {
> @@ -1360,7 +1365,8 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
>  				*call_panic = 2;
>  		} else {
>  			audit_log_format(ab, " obj=%s", ctx);
> -			security_release_secctx(ctx, len);
> +			lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */
> +			security_release_secctx(&lsmcxt);
>  		}
>  	}
>  
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index e05f4ef68bd8..7834c357b60b 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -130,6 +130,7 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
>  
>  static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
>  {
> +	struct lsmcontext context;
>  	struct lsmblob lb;
>  	char *secdata;
>  	u32 seclen;
> @@ -144,7 +145,8 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
>  		return;
>  
>  	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
> -	security_release_secctx(secdata, seclen);
> +	lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */
> +	security_release_secctx(&context);
>  }
>  
>  static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
> diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
> index ca0968f13240..6954e6600583 100644
> --- a/net/netfilter/nf_conntrack_netlink.c
> +++ b/net/netfilter/nf_conntrack_netlink.c
> @@ -331,6 +331,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
>  	int len, ret;
>  	char *secctx;
>  	struct lsmblob blob;
> +	struct lsmcontext context;
>  
>  	lsmblob_init(&blob, ct->secmark);
>  	ret = security_secid_to_secctx(&blob, &secctx, &len);
> @@ -348,7 +349,8 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
>  
>  	ret = 0;
>  nla_put_failure:
> -	security_release_secctx(secctx, len);
> +	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
> +	security_release_secctx(&context);
>  	return ret;
>  }
>  #else
> diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
> index c793103f3cd7..79158ad0486e 100644
> --- a/net/netfilter/nf_conntrack_standalone.c
> +++ b/net/netfilter/nf_conntrack_standalone.c
> @@ -176,6 +176,7 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
>  	u32 len;
>  	char *secctx;
>  	struct lsmblob blob;
> +	struct lsmcontext context;
>  
>  	lsmblob_init(&blob, ct->secmark);
>  	ret = security_secid_to_secctx(&blob, &secctx, &len);
> @@ -184,7 +185,8 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
>  
>  	seq_printf(s, "secctx=%s ", secctx);
>  
> -	security_release_secctx(secctx, len);
> +	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
> +	security_release_secctx(&context);
>  }
>  #else
>  static inline void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index 59211bff90ab..fe8403ef4e89 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -399,6 +399,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	enum ip_conntrack_info uninitialized_var(ctinfo);
>  	struct nfnl_ct_hook *nfnl_ct;
>  	bool csum_verify;
> +	struct lsmcontext scaff; /* scaffolding */
>  	char *secdata = NULL;
>  	u32 seclen = 0;
>  
> @@ -629,8 +630,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	}
>  
>  	nlh->nlmsg_len = skb->len;
> -	if (seclen)
> -		security_release_secctx(secdata, seclen);
> +	if (seclen) {
> +		lsmcontext_init(&scaff, secdata, seclen, 0);
> +		security_release_secctx(&scaff);
> +	}
>  	return skb;
>  
>  nla_put_failure:
> @@ -638,8 +641,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	kfree_skb(skb);
>  	net_err_ratelimited("nf_queue: error creating packet message\n");
>  nlmsg_failure:
> -	if (seclen)
> -		security_release_secctx(secdata, seclen);
> +	if (seclen) {
> +		lsmcontext_init(&scaff, secdata, seclen, 0);
> +		security_release_secctx(&scaff);
> +	}
>  	return NULL;
>  }
>  
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 2294aa9471e6..15b1945853be 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -387,6 +387,7 @@ int netlbl_unlhsh_add(struct net *net,
>  	struct net_device *dev;
>  	struct netlbl_unlhsh_iface *iface;
>  	struct audit_buffer *audit_buf = NULL;
> +	struct lsmcontext context;
>  	char *secctx = NULL;
>  	u32 secctx_len;
>  	struct lsmblob blob;
> @@ -457,7 +458,9 @@ int netlbl_unlhsh_add(struct net *net,
>  					     &secctx,
>  					     &secctx_len) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> -			security_release_secctx(secctx, secctx_len);
> +			/* scaffolding */
> +			lsmcontext_init(&context, secctx, secctx_len, 0);
> +			security_release_secctx(&context);
>  		}
>  		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
>  		audit_log_end(audit_buf);
> @@ -488,6 +491,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  	struct netlbl_unlhsh_addr4 *entry;
>  	struct audit_buffer *audit_buf;
>  	struct net_device *dev;
> +	struct lsmcontext context;
>  	char *secctx;
>  	u32 secctx_len;
>  	struct lsmblob blob;
> @@ -516,7 +520,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  		    security_secid_to_secctx(&blob,
>  					     &secctx, &secctx_len) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> -			security_release_secctx(secctx, secctx_len);
> +			/* scaffolding */
> +			lsmcontext_init(&context, secctx, secctx_len, 0);
> +			security_release_secctx(&context);
>  		}
>  		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
>  		audit_log_end(audit_buf);
> @@ -553,6 +559,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  	struct netlbl_unlhsh_addr6 *entry;
>  	struct audit_buffer *audit_buf;
>  	struct net_device *dev;
> +	struct lsmcontext context;
>  	char *secctx;
>  	u32 secctx_len;
>  	struct lsmblob blob;
> @@ -580,7 +587,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  		    security_secid_to_secctx(&blob,
>  					     &secctx, &secctx_len) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> -			security_release_secctx(secctx, secctx_len);
> +			lsmcontext_init(&context, secctx, secctx_len, 0);
> +			security_release_secctx(&context);
>  		}
>  		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
>  		audit_log_end(audit_buf);
> @@ -1094,6 +1102,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  	int ret_val = -ENOMEM;
>  	struct netlbl_unlhsh_walk_arg *cb_arg = arg;
>  	struct net_device *dev;
> +	struct lsmcontext context;
>  	void *data;
>  	u32 secid;
>  	char *secctx;
> @@ -1161,7 +1170,9 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  			  NLBL_UNLABEL_A_SECCTX,
>  			  secctx_len,
>  			  secctx);
> -	security_release_secctx(secctx, secctx_len);
> +	/* scaffolding */
> +	lsmcontext_init(&context, secctx, secctx_len, 0);
> +	security_release_secctx(&context);
>  	if (ret_val != 0)
>  		goto list_cb_failure;
>  
> diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
> index 2ccc6567e2a2..94aea4985b74 100644
> --- a/net/netlabel/netlabel_user.c
> +++ b/net/netlabel/netlabel_user.c
> @@ -98,6 +98,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>  					       struct netlbl_audit *audit_info)
>  {
>  	struct audit_buffer *audit_buf;
> +	struct lsmcontext context;
>  	char *secctx;
>  	u32 secctx_len;
>  	struct lsmblob blob;
> @@ -117,7 +118,8 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>  	if (audit_info->secid != 0 &&
>  	    security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
>  		audit_log_format(audit_buf, " subj=%s", secctx);
> -		security_release_secctx(secctx, secctx_len);
> +		lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/
> +		security_release_secctx(&context);
>  	}
>  
>  	return audit_buf;
> diff --git a/security/security.c b/security/security.c
> index 92c5aa427b53..d5f173e85393 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -460,6 +460,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
>  		    hooks[i].head == &security_hook_heads.setprocattr ||
>  		    hooks[i].head == &security_hook_heads.secctx_to_secid ||
>  		    hooks[i].head == &security_hook_heads.secid_to_secctx ||
> +		    hooks[i].head == &security_hook_heads.release_secctx ||
>  		    hooks[i].head == &security_hook_heads.ipc_getsecid ||
>  		    hooks[i].head == &security_hook_heads.task_getsecid ||
>  		    hooks[i].head == &security_hook_heads.inode_getsecid ||
> @@ -2091,16 +2092,19 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
>  }
>  EXPORT_SYMBOL(security_secctx_to_secid);
>  
> -void security_release_secctx(char *secdata, u32 seclen)
> +void security_release_secctx(struct lsmcontext *cp)
>  {
>  	struct security_hook_list *hp;
> -	int *display = current->security;
>  
>  	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
> -		if (*display == LSMBLOB_INVALID || *display == hp->slot) {
> -			hp->hook.release_secctx(secdata, seclen);
> +		if (cp->slot == hp->slot) {
> +			hp->hook.release_secctx(cp->context, cp->len);
> +			memset(cp, 0, sizeof(*cp));
>  			return;
>  		}
> +
> +	pr_warn("%s context \"%s\" from slot %d not released\n", __func__,
> +		cp->context, cp->slot);
>  }
>  EXPORT_SYMBOL(security_release_secctx);
>  
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index e9560b078efe..3834b751d1e9 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -4439,11 +4439,16 @@ static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
>  	return 0;
>  }
>  
> -/*
> - * There used to be a smack_release_secctx hook
> - * that did nothing back when hooks were in a vector.
> - * Now that there's a list such a hook adds cost.
> +/**
> + * smack_release_secctx - do everything necessary to free a context
> + * @secdata: Unused
> + * @seclen: Unused
> + *
> + * Do nothing but hold a slot in the hooks list.
>   */
> +static void smack_release_secctx(char *secdata, u32 seclen)
> +{
> +}
>  
>  static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
>  {
> @@ -4683,6 +4688,7 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
>  	LSM_HOOK_INIT(ismaclabel, smack_ismaclabel),
>  	LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx),
>  	LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid),
> +	LSM_HOOK_INIT(release_secctx, smack_release_secctx),
>  	LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx),
>  	LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx),
>  	LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx),
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 17/24] LSM: Use lsmcontext in security_secid_to_secctx
  2019-06-21 18:52 ` [PATCH v3 17/24] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
@ 2019-06-22 22:52   ` Kees Cook
  2019-06-24 21:46   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:52 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:26AM -0700, Casey Schaufler wrote:
> Replace the (secctx,seclen) pointer pair with a single
> lsmcontext pointer to allow return of the LSM identifier
> along with the context and context length. This allows
> security_release_secctx() to know how to release the
> context. Callers have been modified to use or save the
> returned data from the new structure.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  drivers/android/binder.c                | 24 ++++++---------
>  include/linux/security.h                |  4 +--
>  include/net/scm.h                       |  9 ++----
>  kernel/audit.c                          | 29 +++++++-----------
>  kernel/auditsc.c                        | 31 +++++++------------
>  net/ipv4/ip_sockglue.c                  |  7 ++---
>  net/netfilter/nf_conntrack_netlink.c    | 14 +++++----
>  net/netfilter/nf_conntrack_standalone.c |  7 ++---
>  net/netfilter/nfnetlink_queue.c         |  5 +++-
>  net/netlabel/netlabel_unlabeled.c       | 40 ++++++++-----------------
>  net/netlabel/netlabel_user.c            |  7 ++---
>  security/security.c                     |  9 +++---
>  12 files changed, 71 insertions(+), 115 deletions(-)
> 
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 89e574be34cc..5d417a7b9bb3 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -2874,9 +2874,7 @@ static void binder_transaction(struct binder_proc *proc,
>  	binder_size_t last_fixup_min_off = 0;
>  	struct binder_context *context = proc->context;
>  	int t_debug_id = atomic_inc_return(&binder_last_id);
> -	char *secctx = NULL;
> -	u32 secctx_sz = 0;
> -	struct lsmcontext scaff; /* scaffolding */
> +	struct lsmcontext lsmctx;
>  
>  	e = binder_transaction_log_add(&binder_transaction_log);
>  	e->debug_id = t_debug_id;
> @@ -3123,14 +3121,14 @@ static void binder_transaction(struct binder_proc *proc,
>  		struct lsmblob blob;
>  
>  		security_task_getsecid(proc->tsk, &blob);
> -		ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
> +		ret = security_secid_to_secctx(&blob, &lsmctx);
>  		if (ret) {
>  			return_error = BR_FAILED_REPLY;
>  			return_error_param = ret;
>  			return_error_line = __LINE__;
>  			goto err_get_secctx_failed;
>  		}
> -		extra_buffers_size += ALIGN(secctx_sz, sizeof(u64));
> +		extra_buffers_size += ALIGN(lsmctx.len, sizeof(u64));
>  	}
>  
>  	trace_binder_transaction(reply, t, target_node);
> @@ -3149,19 +3147,17 @@ static void binder_transaction(struct binder_proc *proc,
>  		t->buffer = NULL;
>  		goto err_binder_alloc_buf_failed;
>  	}
> -	if (secctx) {
> +	if (lsmctx.context) {
>  		size_t buf_offset = ALIGN(tr->data_size, sizeof(void *)) +
>  				    ALIGN(tr->offsets_size, sizeof(void *)) +
>  				    ALIGN(extra_buffers_size, sizeof(void *)) -
> -				    ALIGN(secctx_sz, sizeof(u64));
> +				    ALIGN(lsmctx.len, sizeof(u64));
>  
>  		t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset;
>  		binder_alloc_copy_to_buffer(&target_proc->alloc,
>  					    t->buffer, buf_offset,
> -					    secctx, secctx_sz);
> -		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
> -		security_release_secctx(&scaff);
> -		secctx = NULL;
> +					    lsmctx.context, lsmctx.len);
> +		security_release_secctx(&lsmctx);
>  	}
>  	t->buffer->debug_id = t->debug_id;
>  	t->buffer->transaction = t;
> @@ -3481,10 +3477,8 @@ static void binder_transaction(struct binder_proc *proc,
>  	t->buffer->transaction = NULL;
>  	binder_alloc_free_buf(&target_proc->alloc, t->buffer);
>  err_binder_alloc_buf_failed:
> -	if (secctx) {
> -		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
> -		security_release_secctx(&scaff);
> -	}
> +	if (lsmctx.context)
> +		security_release_secctx(&lsmctx);
>  err_get_secctx_failed:
>  	kfree(tcomplete);
>  	binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
> diff --git a/include/linux/security.h b/include/linux/security.h
> index ddf6d7cb23f1..3cbe43db16f5 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -477,7 +477,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>  			 size_t size);
>  int security_netlink_send(struct sock *sk, struct sk_buff *skb);
>  int security_ismaclabel(const char *name);
> -int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
> +int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
>  int security_secctx_to_secid(const char *secdata, u32 seclen,
>  			     struct lsmblob *blob);
>  void security_release_secctx(struct lsmcontext *cp);
> @@ -1259,7 +1259,7 @@ static inline int security_ismaclabel(const char *name)
>  }
>  
>  static inline int security_secid_to_secctx(struct lsmblob *blob,
> -					   char **secdata, u32 *seclen)
> +					   struct lsmcontext *cp)
>  {
>  	return -EOPNOTSUPP;
>  }
> diff --git a/include/net/scm.h b/include/net/scm.h
> index 6c7c3c229e4a..4a6ad8caf423 100644
> --- a/include/net/scm.h
> +++ b/include/net/scm.h
> @@ -93,17 +93,14 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
>  static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
>  {
>  	struct lsmcontext context;
> -	char *secdata;
> -	u32 seclen;
>  	int err;
>  
>  	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
> -		err = security_secid_to_secctx(&scm->lsmblob, &secdata,
> -					       &seclen);
> +		err = security_secid_to_secctx(&scm->lsmblob, &context);
>  
>  		if (!err) {
> -			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
> -			lsmcontext_init(&context, secdata, seclen, 0);/*scaffolding*/
> +			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY,
> +				 context.len, context.context);
>  			security_release_secctx(&context);
>  		}
>  	}
> diff --git a/kernel/audit.c b/kernel/audit.c
> index f844a2a642e6..436c23429319 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -1191,9 +1191,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
>  	struct audit_buffer	*ab;
>  	u16			msg_type = nlh->nlmsg_type;
>  	struct audit_sig_info   *sig_data;
> -	char			*ctx = NULL;
>  	u32			len;
> -	struct lsmcontext	scaff; /* scaffolding */
> +	struct lsmcontext	context;
>  
>  	err = audit_netlink_ok(skb, msg_type);
>  	if (err)
> @@ -1431,25 +1430,22 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
>  	case AUDIT_SIGNAL_INFO:
>  		len = 0;
>  		if (lsmblob_is_set(&audit_sig_lsm)) {
> -			err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
> -						       &len);
> +			err = security_secid_to_secctx(&audit_sig_lsm,
> +						       &context);
>  			if (err)
>  				return err;
>  		}
>  		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
>  		if (!sig_data) {
> -			if (lsmblob_is_set(&audit_sig_lsm)) {
> -				lsmcontext_init(&scaff, ctx, len, 0);
> -				security_release_secctx(&scaff);
> -			}
> +			if (lsmblob_is_set(&audit_sig_lsm))
> +				security_release_secctx(&context);
>  			return -ENOMEM;
>  		}
>  		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
>  		sig_data->pid = audit_sig_pid;
>  		if (lsmblob_is_set(&audit_sig_lsm)) {
> -			memcpy(sig_data->ctx, ctx, len);
> -			lsmcontext_init(&scaff, ctx, len, 0);
> -			security_release_secctx(&scaff);
> +			memcpy(sig_data->ctx, context.context, context.len);
> +			security_release_secctx(&context);
>  		}
>  		audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
>  				 sig_data, sizeof(*sig_data) + len);
> @@ -2074,26 +2070,23 @@ void audit_log_key(struct audit_buffer *ab, char *key)
>  
>  int audit_log_task_context(struct audit_buffer *ab)
>  {
> -	char *ctx = NULL;
> -	unsigned len;
>  	int error;
>  	struct lsmblob blob;
> -	struct lsmcontext scaff; /* scaffolding */
> +	struct lsmcontext context;
>  
>  	security_task_getsecid(current, &blob);
>  	if (!lsmblob_is_set(&blob))
>  		return 0;
>  
> -	error = security_secid_to_secctx(&blob, &ctx, &len);
> +	error = security_secid_to_secctx(&blob, &context);
>  	if (error) {
>  		if (error != -EINVAL)
>  			goto error_path;
>  		return 0;
>  	}
>  
> -	audit_log_format(ab, " subj=%s", ctx);
> -	lsmcontext_init(&scaff, ctx, len, 0);
> -	security_release_secctx(&scaff);
> +	audit_log_format(ab, " subj=%s", context.context);
> +	security_release_secctx(&context);
>  	return 0;
>  
>  error_path:
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 9fab0e7d90c3..0478680cd0a8 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -943,9 +943,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  				 struct lsmblob *blob, char *comm)
>  {
>  	struct audit_buffer *ab;
> -	struct lsmcontext lsmcxt;
> -	char *ctx = NULL;
> -	u32 len;
> +	struct lsmcontext lsmctx;
>  	int rc = 0;
>  
>  	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
> @@ -956,13 +954,12 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  			 from_kuid(&init_user_ns, auid),
>  			 from_kuid(&init_user_ns, uid), sessionid);
>  	if (lsmblob_is_set(blob)) {
> -		if (security_secid_to_secctx(blob, &ctx, &len)) {
> +		if (security_secid_to_secctx(blob, &lsmctx)) {
>  			audit_log_format(ab, " obj=(none)");
>  			rc = 1;
>  		} else {
> -			audit_log_format(ab, " obj=%s", ctx);
> -			lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/
> -			security_release_secctx(&lsmcxt);
> +			audit_log_format(ab, " obj=%s", lsmctx.context);
> +			security_release_secctx(&lsmctx);
>  		}
>  	}
>  	audit_log_format(ab, " ocomm=");
> @@ -1174,7 +1171,6 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
>  
>  static void show_special(struct audit_context *context, int *call_panic)
>  {
> -	struct lsmcontext lsmcxt;
>  	struct audit_buffer *ab;
>  	int i;
>  
> @@ -1198,17 +1194,15 @@ static void show_special(struct audit_context *context, int *call_panic)
>  				 from_kgid(&init_user_ns, context->ipc.gid),
>  				 context->ipc.mode);
>  		if (osid) {
> -			char *ctx = NULL;
> -			u32 len;
> +			struct lsmcontext lsmcxt;
>  			struct lsmblob blob;
>  
>  			lsmblob_init(&blob, osid);
> -			if (security_secid_to_secctx(&blob, &ctx, &len)) {
> +			if (security_secid_to_secctx(&blob, &lsmcxt)) {
>  				audit_log_format(ab, " osid=%u", osid);
>  				*call_panic = 1;
>  			} else {
> -				audit_log_format(ab, " obj=%s", ctx);
> -				lsmcontext_init(&lsmcxt, ctx, len, 0);
> +				audit_log_format(ab, " obj=%s", lsmcxt.context);
>  				security_release_secctx(&lsmcxt);
>  			}
>  		}
> @@ -1353,20 +1347,17 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
>  				 MAJOR(n->rdev),
>  				 MINOR(n->rdev));
>  	if (n->osid != 0) {
> -		char *ctx = NULL;
> -		u32 len;
>  		struct lsmblob blob;
> -		struct lsmcontext lsmcxt;
> +		struct lsmcontext lsmctx;
>  
>  		lsmblob_init(&blob, n->osid);
> -		if (security_secid_to_secctx(&blob, &ctx, &len)) {
> +		if (security_secid_to_secctx(&blob, &lsmctx)) {
>  			audit_log_format(ab, " osid=%u", n->osid);
>  			if (call_panic)
>  				*call_panic = 2;
>  		} else {
> -			audit_log_format(ab, " obj=%s", ctx);
> -			lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */
> -			security_release_secctx(&lsmcxt);
> +			audit_log_format(ab, " obj=%s", lsmctx.context);
> +			security_release_secctx(&lsmctx);
>  		}
>  	}
>  
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index 7834c357b60b..80ae0c5a1301 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -132,20 +132,17 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
>  {
>  	struct lsmcontext context;
>  	struct lsmblob lb;
> -	char *secdata;
> -	u32 seclen;
>  	int err;
>  
>  	err = security_socket_getpeersec_dgram(NULL, skb, &lb);
>  	if (err)
>  		return;
>  
> -	err = security_secid_to_secctx(&lb, &secdata, &seclen);
> +	err = security_secid_to_secctx(&lb, &context);
>  	if (err)
>  		return;
>  
> -	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
> -	lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */
> +	put_cmsg(msg, SOL_IP, SCM_SECURITY, context.len, context.context);
>  	security_release_secctx(&context);
>  }
>  
> diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
> index 6954e6600583..403307ff0fff 100644
> --- a/net/netfilter/nf_conntrack_netlink.c
> +++ b/net/netfilter/nf_conntrack_netlink.c
> @@ -328,13 +328,12 @@ static int ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct)
>  static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
>  {
>  	struct nlattr *nest_secctx;
> -	int len, ret;
> -	char *secctx;
> +	int ret;
>  	struct lsmblob blob;
>  	struct lsmcontext context;
>  
>  	lsmblob_init(&blob, ct->secmark);
> -	ret = security_secid_to_secctx(&blob, &secctx, &len);
> +	ret = security_secid_to_secctx(&blob, &context);
>  	if (ret)
>  		return 0;
>  
> @@ -343,13 +342,12 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
>  	if (!nest_secctx)
>  		goto nla_put_failure;
>  
> -	if (nla_put_string(skb, CTA_SECCTX_NAME, secctx))
> +	if (nla_put_string(skb, CTA_SECCTX_NAME, context.context))
>  		goto nla_put_failure;
>  	nla_nest_end(skb, nest_secctx);
>  
>  	ret = 0;
>  nla_put_failure:
> -	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
>  	security_release_secctx(&context);
>  	return ret;
>  }
> @@ -620,12 +618,16 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
>  #ifdef CONFIG_NF_CONNTRACK_SECMARK
>  	int len, ret;
>  	struct lsmblob blob;
> +	struct lsmcontext context;
>  
>  	lsmblob_init(&blob, ct->secmark);
> -	ret = security_secid_to_secctx(&blob, NULL, &len);
> +	ret = security_secid_to_secctx(&blob, &context);
>  	if (ret)
>  		return 0;
>  
> +	len = context.len;
> +	security_release_secctx(&context);
> +
>  	return nla_total_size(0) /* CTA_SECCTX */
>  	       + nla_total_size(sizeof(char) * len); /* CTA_SECCTX_NAME */
>  #else
> diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
> index 79158ad0486e..fcb51ab2bb8b 100644
> --- a/net/netfilter/nf_conntrack_standalone.c
> +++ b/net/netfilter/nf_conntrack_standalone.c
> @@ -173,19 +173,16 @@ static void ct_seq_stop(struct seq_file *s, void *v)
>  static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
>  {
>  	int ret;
> -	u32 len;
> -	char *secctx;
>  	struct lsmblob blob;
>  	struct lsmcontext context;
>  
>  	lsmblob_init(&blob, ct->secmark);
> -	ret = security_secid_to_secctx(&blob, &secctx, &len);
> +	ret = security_secid_to_secctx(&blob, &context);
>  	if (ret)
>  		return;
>  
> -	seq_printf(s, "secctx=%s ", secctx);
> +	seq_printf(s, "secctx=%s ", context.context);
>  
> -	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
>  	security_release_secctx(&context);
>  }
>  #else
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index fe8403ef4e89..6da00c7add5b 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -310,6 +310,7 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
>  	u32 seclen = 0;
>  #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
>  	struct lsmblob blob;
> +	struct lsmcontext context;
>  
>  	if (!skb || !sk_fullsock(skb->sk))
>  		return 0;
> @@ -318,10 +319,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
>  
>  	if (skb->secmark) {
>  		lsmblob_init(&blob, skb->secmark);
> -		security_secid_to_secctx(&blob, secdata, &seclen);
> +		security_secid_to_secctx(&blob, &context);
> +		*secdata = context.context;
>  	}
>  
>  	read_unlock_bh(&skb->sk->sk_callback_lock);
> +	seclen = context.len;
>  #endif
>  	return seclen;
>  }
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 15b1945853be..4716e0011ba5 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -388,8 +388,6 @@ int netlbl_unlhsh_add(struct net *net,
>  	struct netlbl_unlhsh_iface *iface;
>  	struct audit_buffer *audit_buf = NULL;
>  	struct lsmcontext context;
> -	char *secctx = NULL;
> -	u32 secctx_len;
>  	struct lsmblob blob;
>  
>  	if (addr_len != sizeof(struct in_addr) &&
> @@ -454,12 +452,9 @@ int netlbl_unlhsh_add(struct net *net,
>  	rcu_read_unlock();
>  	if (audit_buf != NULL) {
>  		lsmblob_init(&blob, secid);
> -		if (security_secid_to_secctx(&blob,
> -					     &secctx,
> -					     &secctx_len) == 0) {
> -			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> -			/* scaffolding */
> -			lsmcontext_init(&context, secctx, secctx_len, 0);
> +		if (security_secid_to_secctx(&blob, &context) == 0) {
> +			audit_log_format(audit_buf, " sec_obj=%s",
> +					 context.context);
>  			security_release_secctx(&context);
>  		}
>  		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
> @@ -492,8 +487,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  	struct audit_buffer *audit_buf;
>  	struct net_device *dev;
>  	struct lsmcontext context;
> -	char *secctx;
> -	u32 secctx_len;
>  	struct lsmblob blob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
> @@ -517,11 +510,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  		if (entry != NULL)
>  			lsmblob_init(&blob, entry->secid);
>  		if (entry != NULL &&
> -		    security_secid_to_secctx(&blob,
> -					     &secctx, &secctx_len) == 0) {
> -			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> -			/* scaffolding */
> -			lsmcontext_init(&context, secctx, secctx_len, 0);
> +		    security_secid_to_secctx(&blob, &context) == 0) {
> +			audit_log_format(audit_buf, " sec_obj=%s",
> +					 context.context);
>  			security_release_secctx(&context);
>  		}
>  		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
> @@ -560,8 +551,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  	struct audit_buffer *audit_buf;
>  	struct net_device *dev;
>  	struct lsmcontext context;
> -	char *secctx;
> -	u32 secctx_len;
>  	struct lsmblob blob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
> @@ -584,10 +573,9 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  		if (entry != NULL)
>  			lsmblob_init(&blob, entry->secid);
>  		if (entry != NULL &&
> -		    security_secid_to_secctx(&blob,
> -					     &secctx, &secctx_len) == 0) {
> -			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> -			lsmcontext_init(&context, secctx, secctx_len, 0);
> +		    security_secid_to_secctx(&blob, &context) == 0) {
> +			audit_log_format(audit_buf, " sec_obj=%s",
> +					 context.context);
>  			security_release_secctx(&context);
>  		}
>  		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
> @@ -1105,8 +1093,6 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  	struct lsmcontext context;
>  	void *data;
>  	u32 secid;
> -	char *secctx;
> -	u32 secctx_len;
>  	struct lsmblob blob;
>  
>  	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
> @@ -1163,15 +1149,13 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  	}
>  
>  	lsmblob_init(&blob, secid);
> -	ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
> +	ret_val = security_secid_to_secctx(&blob, &context);
>  	if (ret_val != 0)
>  		goto list_cb_failure;
>  	ret_val = nla_put(cb_arg->skb,
>  			  NLBL_UNLABEL_A_SECCTX,
> -			  secctx_len,
> -			  secctx);
> -	/* scaffolding */
> -	lsmcontext_init(&context, secctx, secctx_len, 0);
> +			  context.len,
> +			  context.context);
>  	security_release_secctx(&context);
>  	if (ret_val != 0)
>  		goto list_cb_failure;
> diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
> index 94aea4985b74..2d1307f65250 100644
> --- a/net/netlabel/netlabel_user.c
> +++ b/net/netlabel/netlabel_user.c
> @@ -99,8 +99,6 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>  {
>  	struct audit_buffer *audit_buf;
>  	struct lsmcontext context;
> -	char *secctx;
> -	u32 secctx_len;
>  	struct lsmblob blob;
>  
>  	if (audit_enabled == AUDIT_OFF)
> @@ -116,9 +114,8 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>  
>  	lsmblob_init(&blob, audit_info->secid);
>  	if (audit_info->secid != 0 &&
> -	    security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
> -		audit_log_format(audit_buf, " subj=%s", secctx);
> -		lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/
> +	    security_secid_to_secctx(&blob, &context) == 0) {
> +		audit_log_format(audit_buf, " subj=%s", context.context);
>  		security_release_secctx(&context);
>  	}
>  
> diff --git a/security/security.c b/security/security.c
> index d5f173e85393..f461ab3fb9c4 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -459,7 +459,6 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
>  		    hooks[i].head == &security_hook_heads.getprocattr ||
>  		    hooks[i].head == &security_hook_heads.setprocattr ||
>  		    hooks[i].head == &security_hook_heads.secctx_to_secid ||
> -		    hooks[i].head == &security_hook_heads.secid_to_secctx ||
>  		    hooks[i].head == &security_hook_heads.release_secctx ||
>  		    hooks[i].head == &security_hook_heads.ipc_getsecid ||
>  		    hooks[i].head == &security_hook_heads.task_getsecid ||
> @@ -2064,15 +2063,17 @@ int security_ismaclabel(const char *name)
>  }
>  EXPORT_SYMBOL(security_ismaclabel);
>  
> -int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
> +int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
>  {
>  	struct security_hook_list *hp;
>  	int *display = current->security;
>  
>  	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list)
> -		if (*display == LSMBLOB_INVALID || *display == hp->slot)
> +		if (*display == LSMBLOB_INVALID || *display == hp->slot) {
> +			cp->slot = hp->slot;
>  			return hp->hook.secid_to_secctx(blob->secid[hp->slot],
> -							secdata, seclen);
> +							&cp->context, &cp->len);
> +		}
>  	return 0;
>  }
>  EXPORT_SYMBOL(security_secid_to_secctx);
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 18/24] LSM: Use lsmcontext in security_dentry_init_security
  2019-06-21 18:52 ` [PATCH v3 18/24] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
@ 2019-06-22 22:54   ` Kees Cook
  2019-06-24 21:46   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:54 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:27AM -0700, Casey Schaufler wrote:
> Change the security_dentry_init_security() interface to
> fill an lsmcontext structure instead of a void * data area
> and a length. The lone caller of this interface is NFS4,
> which may make copies of the data using its own mechanisms.
> A rework of the nfs4 code to use the lsmcontext properly
> is a significant project, so the coward's way out is taken,
> and the lsmcontext data from security_dentry_init_security()
> is copied, then released directly.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---
>  fs/nfs/nfs4proc.c        | 26 ++++++++++++++++----------
>  include/linux/security.h |  7 +++----
>  security/security.c      | 20 ++++++++++++++++----
>  3 files changed, 35 insertions(+), 18 deletions(-)
> 
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index af1c0db29c39..952f805965bb 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -113,6 +113,7 @@ static inline struct nfs4_label *
>  nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
>  	struct iattr *sattr, struct nfs4_label *label)
>  {
> +	struct lsmcontext context;
>  	int err;
>  
>  	if (label == NULL)
> @@ -122,21 +123,26 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
>  		return NULL;
>  
>  	err = security_dentry_init_security(dentry, sattr->ia_mode,
> -				&dentry->d_name, (void **)&label->label, &label->len);
> -	if (err == 0)
> -		return label;
> +					    &dentry->d_name, &context);
> +
> +	if (err)
> +		return NULL;
> +
> +	label->label = kmemdup(context.context, context.len, GFP_KERNEL);
> +	if (label->label == NULL)
> +		label = NULL;
> +	else
> +		label->len = context.len;
> +
> +	security_release_secctx(&context);
> +
> +	return label;
>  
> -	return NULL;
>  }
>  static inline void
>  nfs4_label_release_security(struct nfs4_label *label)
>  {
> -	struct lsmcontext scaff; /* scaffolding */
> -
> -	if (label) {
> -		lsmcontext_init(&scaff, label->label, label->len, 0);
> -		security_release_secctx(&scaff);
> -	}
> +	kfree(label->label);
>  }
>  static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label)
>  {
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 3cbe43db16f5..2a2785a4e752 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -348,8 +348,8 @@ int security_sb_clone_mnt_opts(const struct super_block *oldsb,
>  int security_add_mnt_opt(const char *option, const char *val,
>  				int len, void **mnt_opts);
>  int security_dentry_init_security(struct dentry *dentry, int mode,
> -					const struct qstr *name, void **ctx,
> -					u32 *ctxlen);
> +					const struct qstr *name,
> +					struct lsmcontext *ctx);
>  int security_dentry_create_files_as(struct dentry *dentry, int mode,
>  					struct qstr *name,
>  					const struct cred *old,
> @@ -720,8 +720,7 @@ static inline void security_inode_free(struct inode *inode)
>  static inline int security_dentry_init_security(struct dentry *dentry,
>  						 int mode,
>  						 const struct qstr *name,
> -						 void **ctx,
> -						 u32 *ctxlen)
> +						 struct lsmcontext *ctx)
>  {
>  	return -EOPNOTSUPP;
>  }
> diff --git a/security/security.c b/security/security.c
> index f461ab3fb9c4..842ac65abc08 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -453,6 +453,8 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
>  		 * secid in the lsmblob structure.
>  		 */
>  		if (hooks[i].head == &security_hook_heads.audit_rule_match ||
> +		    hooks[i].head ==
> +			&security_hook_heads.dentry_init_security ||
>  		    hooks[i].head == &security_hook_heads.kernel_act_as ||
>  		    hooks[i].head ==
>  			&security_hook_heads.socket_getpeersec_dgram ||
> @@ -1040,11 +1042,21 @@ void security_inode_free(struct inode *inode)
>  }
>  
>  int security_dentry_init_security(struct dentry *dentry, int mode,
> -					const struct qstr *name, void **ctx,
> -					u32 *ctxlen)
> +				  const struct qstr *name,
> +				  struct lsmcontext *cp)
>  {
> -	return call_int_hook(dentry_init_security, -EOPNOTSUPP, dentry, mode,
> -				name, ctx, ctxlen);
> +	int *display = current->security;
> +	struct security_hook_list *hp;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.dentry_init_security,
> +			     list)
> +		if (*display == 0 || *display == hp->slot) {

Is this supposed to be == -1 not 0? Isn't 0 an assigned slot?

Otherwise:

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> +			cp->slot = hp->slot;
> +			return hp->hook.dentry_init_security(dentry, mode,
> +					name, (void **)&cp->context, &cp->len);
> +		}
> +
> +	return -EOPNOTSUPP;
>  }
>  EXPORT_SYMBOL(security_dentry_init_security);
>  
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 19/24] LSM: Use lsmcontext in security_inode_getsecctx
  2019-06-21 18:52 ` [PATCH v3 19/24] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
@ 2019-06-22 22:56   ` Kees Cook
  2019-06-24 21:46   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:56 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:28AM -0700, Casey Schaufler wrote:
> Change the security_inode_getsecctx() interface to fill
> a lsmcontext structure instead of data and length pointers.
> This provides the information about which LSM created the
> context so that security_release_secctx() can use the
> correct hook. A lsmcontext is used within kernfs to store
> the security information as well.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  fs/kernfs/dir.c             |  8 ++------
>  fs/kernfs/inode.c           | 34 ++++++++++++----------------------
>  fs/kernfs/kernfs-internal.h |  3 +--
>  fs/nfsd/nfs4xdr.c           | 23 +++++++++--------------
>  include/linux/security.h    |  5 +++--
>  security/security.c         | 13 +++++++++++--
>  6 files changed, 38 insertions(+), 48 deletions(-)
> 
> diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
> index 92afad387237..1d000289d8b7 100644
> --- a/fs/kernfs/dir.c
> +++ b/fs/kernfs/dir.c
> @@ -532,12 +532,8 @@ void kernfs_put(struct kernfs_node *kn)
>  	kfree_const(kn->name);
>  
>  	if (kn->iattr) {
> -		struct lsmcontext scaff; /* scaffolding */
> -		if (kn->iattr->ia_secdata) {
> -			lsmcontext_init(&scaff, kn->iattr->ia_secdata,
> -					kn->iattr->ia_secdata_len, 0);
> -			security_release_secctx(&scaff);
> -		}
> +		if (kn->iattr->ia_context.context)
> +			security_release_secctx(&kn->iattr->ia_context);
>  		simple_xattrs_free(&kn->iattr->xattrs);
>  		kmem_cache_free(kernfs_iattrs_cache, kn->iattr);
>  	}
> diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
> index 02cde9dac5ee..ffbf7863306d 100644
> --- a/fs/kernfs/inode.c
> +++ b/fs/kernfs/inode.c
> @@ -135,21 +135,14 @@ int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr)
>  	return error;
>  }
>  
> -static int kernfs_node_setsecdata(struct kernfs_iattrs *attrs, void **secdata,
> -				  u32 *secdata_len)
> +static void kernfs_node_setsecdata(struct kernfs_iattrs *attrs,
> +				   struct lsmcontext *cp)
>  {
> -	void *old_secdata;
> -	size_t old_secdata_len;
> +	struct lsmcontext old_context;
>  
> -	old_secdata = attrs->ia_secdata;
> -	old_secdata_len = attrs->ia_secdata_len;
> -
> -	attrs->ia_secdata = *secdata;
> -	attrs->ia_secdata_len = *secdata_len;
> -
> -	*secdata = old_secdata;
> -	*secdata_len = old_secdata_len;
> -	return 0;
> +	old_context = attrs->ia_context;
> +	attrs->ia_context = *cp;
> +	*cp = old_context;
>  }
>  
>  ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size)
> @@ -192,8 +185,8 @@ static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode)
>  		 * persistent copy in kernfs_node.
>  		 */
>  		set_inode_attr(inode, &attrs->ia_iattr);
> -		security_inode_notifysecctx(inode, attrs->ia_secdata,
> -					    attrs->ia_secdata_len);
> +		security_inode_notifysecctx(inode, attrs->ia_context.context,
> +					    attrs->ia_context.len);
>  	}
>  
>  	if (kernfs_type(kn) == KERNFS_DIR)
> @@ -350,8 +343,6 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler,
>  	struct kernfs_node *kn = inode->i_private;
>  	struct kernfs_iattrs *attrs;
>  	struct lsmcontext context;
> -	void *secdata;
> -	u32 secdata_len = 0;
>  	int error;
>  
>  	attrs = kernfs_iattrs(kn);
> @@ -361,18 +352,17 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler,
>  	error = security_inode_setsecurity(inode, suffix, value, size, flags);
>  	if (error)
>  		return error;
> -	error = security_inode_getsecctx(inode, &secdata, &secdata_len);
> +	error = security_inode_getsecctx(inode, &context);
>  	if (error)
>  		return error;
>  
>  	mutex_lock(&kernfs_mutex);
> -	error = kernfs_node_setsecdata(attrs, &secdata, &secdata_len);
> +	kernfs_node_setsecdata(attrs, &context);
>  	mutex_unlock(&kernfs_mutex);
>  
> -	if (secdata) {
> -		lsmcontext_init(&context, secdata, secdata_len, 0);
> +	if (context.context)
>  		security_release_secctx(&context);
> -	}
> +
>  	return error;
>  }
>  
> diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
> index 0b7d197a904c..844a028d282f 100644
> --- a/fs/kernfs/kernfs-internal.h
> +++ b/fs/kernfs/kernfs-internal.h
> @@ -21,8 +21,7 @@
>  
>  struct kernfs_iattrs {
>  	struct iattr		ia_iattr;
> -	void			*ia_secdata;
> -	u32			ia_secdata_len;
> +	struct lsmcontext	ia_context;
>  
>  	struct simple_xattrs	xattrs;
>  };
> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index bb3db033e144..1209083565dd 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -2304,11 +2304,11 @@ nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types)
>  #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
>  static inline __be32
>  nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
> -			    void *context, int len)
> +			    struct lsmcontext *context)
>  {
>  	__be32 *p;
>  
> -	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
> +	p = xdr_reserve_space(xdr, context->len + 4 + 4 + 4);
>  	if (!p)
>  		return nfserr_resource;
>  
> @@ -2318,13 +2318,13 @@ nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
>  	 */
>  	*p++ = cpu_to_be32(0); /* lfs */
>  	*p++ = cpu_to_be32(0); /* pi */
> -	p = xdr_encode_opaque(p, context, len);
> +	p = xdr_encode_opaque(p, context->context, context->len);
>  	return 0;
>  }
>  #else
>  static inline __be32
>  nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
> -			    void *context, int len)
> +			    struct lsmcontext *context)
>  { return 0; }
>  #endif
>  
> @@ -2420,9 +2420,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
>  	__be32 status;
>  	int err;
>  	struct nfs4_acl *acl = NULL;
> -	struct lsmcontext scaff; /* scaffolding */
> -	void *context = NULL;
> -	int contextlen;
> +	struct lsmcontext context;
>  	bool contextsupport = false;
>  	struct nfsd4_compoundres *resp = rqstp->rq_resp;
>  	u32 minorversion = resp->cstate.minorversion;
> @@ -2479,7 +2477,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
>  	     bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
>  		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
>  			err = security_inode_getsecctx(d_inode(dentry),
> -						&context, &contextlen);
> +						       &context);
>  		else
>  			err = -EOPNOTSUPP;
>  		contextsupport = (err == 0);
> @@ -2908,8 +2906,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
>  	}
>  
>  	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
> -		status = nfsd4_encode_security_label(xdr, rqstp, context,
> -								contextlen);
> +		status = nfsd4_encode_security_label(xdr, rqstp, &context);
>  		if (status)
>  			goto out;
>  	}
> @@ -2920,10 +2917,8 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
>  
>  out:
>  #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
> -	if (context) {
> -		lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/
> -		security_release_secctx(&scaff);
> -	}
> +	if (context.context)
> +		security_release_secctx(&context);
>  #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
>  	kfree(acl);
>  	if (tempfh) {
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 2a2785a4e752..bfdb06bc5466 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -485,7 +485,7 @@ void security_release_secctx(struct lsmcontext *cp);
>  void security_inode_invalidate_secctx(struct inode *inode);
>  int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
>  int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
> -int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
> +int security_inode_getsecctx(struct inode *inode, struct lsmcontext *cp);
>  #else /* CONFIG_SECURITY */
>  
>  static inline int call_lsm_notifier(enum lsm_event event, void *data)
> @@ -1286,7 +1286,8 @@ static inline int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32
>  {
>  	return -EOPNOTSUPP;
>  }
> -static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
> +static inline int security_inode_getsecctx(struct inode *inode,
> +					   struct lsmcontext *cp)
>  {
>  	return -EOPNOTSUPP;
>  }
> diff --git a/security/security.c b/security/security.c
> index 842ac65abc08..b2ffcd1f3057 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2139,9 +2139,18 @@ int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
>  }
>  EXPORT_SYMBOL(security_inode_setsecctx);
>  
> -int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
> +int security_inode_getsecctx(struct inode *inode, struct lsmcontext *cp)
>  {
> -	return call_int_hook(inode_getsecctx, -EOPNOTSUPP, inode, ctx, ctxlen);
> +	int *display = current->security;
> +	struct security_hook_list *hp;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.inode_getsecctx, list)
> +		if (*display == 0 || *display == hp->slot) {
> +			cp->slot = hp->slot;
> +			return hp->hook.inode_getsecctx(inode,
> +					(void **)&cp->context, &cp->len);
> +		}
> +	return -EOPNOTSUPP;
>  }
>  EXPORT_SYMBOL(security_inode_getsecctx);
>  
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 20/24] LSM: security_secid_to_secctx in netlink netfilter
  2019-06-21 18:52 ` [PATCH v3 20/24] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
@ 2019-06-22 22:57   ` Kees Cook
  2019-06-24 21:47   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 22:57 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:29AM -0700, Casey Schaufler wrote:
> Change netlink netfilter interfaces to use lsmcontext
> pointers, and remove scaffolding.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  net/netfilter/nfnetlink_queue.c | 32 +++++++++++++-------------------
>  1 file changed, 13 insertions(+), 19 deletions(-)
> 
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index 6da00c7add5b..69efb688383f 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -305,12 +305,10 @@ static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
>  	return -1;
>  }
>  
> -static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
> +static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context)
>  {
> -	u32 seclen = 0;
>  #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
>  	struct lsmblob blob;
> -	struct lsmcontext context;
>  
>  	if (!skb || !sk_fullsock(skb->sk))
>  		return 0;
> @@ -318,15 +316,16 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
>  	read_lock_bh(&skb->sk->sk_callback_lock);
>  
>  	if (skb->secmark) {
> +		/* Any LSM might be looking for the secmark */
>  		lsmblob_init(&blob, skb->secmark);
> -		security_secid_to_secctx(&blob, &context);
> -		*secdata = context.context;
> +		security_secid_to_secctx(&blob, context);
>  	}
>  
>  	read_unlock_bh(&skb->sk->sk_callback_lock);
> -	seclen = context.len;
> +	return context->len;
> +#else
> +	return 0;
>  #endif
> -	return seclen;
>  }
>  
>  static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
> @@ -402,8 +401,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	enum ip_conntrack_info uninitialized_var(ctinfo);
>  	struct nfnl_ct_hook *nfnl_ct;
>  	bool csum_verify;
> -	struct lsmcontext scaff; /* scaffolding */
> -	char *secdata = NULL;
> +	struct lsmcontext context;
>  	u32 seclen = 0;
>  
>  	size =    nlmsg_total_size(sizeof(struct nfgenmsg))
> @@ -470,7 +468,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	}
>  
>  	if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
> -		seclen = nfqnl_get_sk_secctx(entskb, &secdata);
> +		seclen = nfqnl_get_sk_secctx(entskb, &context);
>  		if (seclen)
>  			size += nla_total_size(seclen);
>  	}
> @@ -605,7 +603,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	    nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
>  		goto nla_put_failure;
>  
> -	if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
> +	if (seclen && nla_put(skb, NFQA_SECCTX, context.len, context.context))
>  		goto nla_put_failure;
>  
>  	if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
> @@ -633,10 +631,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	}
>  
>  	nlh->nlmsg_len = skb->len;
> -	if (seclen) {
> -		lsmcontext_init(&scaff, secdata, seclen, 0);
> -		security_release_secctx(&scaff);
> -	}
> +	if (seclen)
> +		security_release_secctx(&context);
>  	return skb;
>  
>  nla_put_failure:
> @@ -644,10 +640,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	kfree_skb(skb);
>  	net_err_ratelimited("nf_queue: error creating packet message\n");
>  nlmsg_failure:
> -	if (seclen) {
> -		lsmcontext_init(&scaff, secdata, seclen, 0);
> -		security_release_secctx(&scaff);
> -	}
> +	if (seclen)
> +		security_release_secctx(&context);
>  	return NULL;
>  }
>  
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob
  2019-06-21 18:52 ` [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob Casey Schaufler
@ 2019-06-22 23:12   ` Kees Cook
  2019-06-24 21:33   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 23:12 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:30AM -0700, Casey Schaufler wrote:
> Change the audit code to store full lsmblob data instead of
> a single u32 secid. This allows for multiple security modules
> to use the audit system at the same time. It also allows the
> removal of scaffolding code that was included during the
> revision of LSM interfaces.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---
>  kernel/audit.h   |  6 +++---
>  kernel/auditsc.c | 38 +++++++++++---------------------------
>  2 files changed, 14 insertions(+), 30 deletions(-)
> 
> diff --git a/kernel/audit.h b/kernel/audit.h
> index 29e29c6f4afb..a8dd479e9556 100644
> --- a/kernel/audit.h
> +++ b/kernel/audit.h
> @@ -91,7 +91,7 @@ struct audit_names {
>  	kuid_t			uid;
>  	kgid_t			gid;
>  	dev_t			rdev;
> -	u32			osid;
> +	struct lsmblob		olsm;
>  	struct audit_cap_data	fcap;
>  	unsigned int		fcap_ver;
>  	unsigned char		type;		/* record type */
> @@ -148,7 +148,7 @@ struct audit_context {
>  	kuid_t		    target_auid;
>  	kuid_t		    target_uid;
>  	unsigned int	    target_sessionid;
> -	struct lsmblob   target_lsm;
> +	struct lsmblob	    target_lsm;
>  	char		    target_comm[TASK_COMM_LEN];
>  
>  	struct audit_tree_refs *trees, *first_trees;
> @@ -165,7 +165,7 @@ struct audit_context {
>  			kuid_t			uid;
>  			kgid_t			gid;
>  			umode_t			mode;
> -			u32			osid;
> +			struct lsmblob		olsm;
>  			int			has_perm;
>  			uid_t			perm_uid;
>  			gid_t			perm_gid;
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 0478680cd0a8..d3ad13f11788 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -646,17 +646,15 @@ static int audit_filter_rules(struct task_struct *tsk,
>  			if (f->lsm_rule) {
>  				/* Find files that match */
>  				if (name) {
> -					lsmblob_init(&blob, name->osid);
>  					result = security_audit_rule_match(
> -								&blob,
> +								&name->olsm,
>  								f->type,
>  								f->op,
>  								f->lsm_rule);
>  				} else if (ctx) {
>  					list_for_each_entry(n, &ctx->names_list, list) {
> -						lsmblob_init(&blob, n->osid);
>  						if (security_audit_rule_match(
> -								&blob,
> +								&n->olsm,
>  								f->type,
>  								f->op,
>  								f->lsm_rule)) {
> @@ -668,8 +666,7 @@ static int audit_filter_rules(struct task_struct *tsk,
>  				/* Find ipc objects that match */
>  				if (!ctx || ctx->type != AUDIT_IPC)
>  					break;
> -				lsmblob_init(&blob, ctx->ipc.osid);
> -				if (security_audit_rule_match(&blob,
> +				if (security_audit_rule_match(&ctx->ipc.olsm,
>  							      f->type, f->op,
>  							      f->lsm_rule))
>  					++result;
> @@ -1187,21 +1184,18 @@ static void show_special(struct audit_context *context, int *call_panic)
>  				context->socketcall.args[i]);
>  		break; }
>  	case AUDIT_IPC: {
> -		u32 osid = context->ipc.osid;
> +		struct lsmblob *olsm = &context->ipc.olsm;
>  
>  		audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
>  				 from_kuid(&init_user_ns, context->ipc.uid),
>  				 from_kgid(&init_user_ns, context->ipc.gid),
>  				 context->ipc.mode);
> -		if (osid) {
> +		if (lsmblob_is_set(olsm)) {
>  			struct lsmcontext lsmcxt;
> -			struct lsmblob blob;
>  
> -			lsmblob_init(&blob, osid);
> -			if (security_secid_to_secctx(&blob, &lsmcxt)) {
> -				audit_log_format(ab, " osid=%u", osid);

Should this (and the other) audit_log_format() calls actually be
removed?

-Kees

> +			if (security_secid_to_secctx(olsm, &lsmcxt))
>  				*call_panic = 1;
> -			} else {
> +			else {
>  				audit_log_format(ab, " obj=%s", lsmcxt.context);
>  				security_release_secctx(&lsmcxt);
>  			}
> @@ -1346,13 +1340,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
>  				 from_kgid(&init_user_ns, n->gid),
>  				 MAJOR(n->rdev),
>  				 MINOR(n->rdev));
> -	if (n->osid != 0) {
> -		struct lsmblob blob;
> +	if (lsmblob_is_set(&n->olsm)) {
>  		struct lsmcontext lsmctx;
>  
> -		lsmblob_init(&blob, n->osid);
> -		if (security_secid_to_secctx(&blob, &lsmctx)) {
> -			audit_log_format(ab, " osid=%u", n->osid);
> +		if (security_secid_to_secctx(&n->olsm, &lsmctx)) {
>  			if (call_panic)
>  				*call_panic = 2;
>  		} else {
> @@ -1906,17 +1897,13 @@ static inline int audit_copy_fcaps(struct audit_names *name,
>  void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
>  		      struct inode *inode, unsigned int flags)
>  {
> -	struct lsmblob blob;
> -
>  	name->ino   = inode->i_ino;
>  	name->dev   = inode->i_sb->s_dev;
>  	name->mode  = inode->i_mode;
>  	name->uid   = inode->i_uid;
>  	name->gid   = inode->i_gid;
>  	name->rdev  = inode->i_rdev;
> -	security_inode_getsecid(inode, &blob);
> -	/* scaffolding until osid is updated */
> -	name->osid = blob.secid[0];
> +	security_inode_getsecid(inode, &name->olsm);
>  	if (flags & AUDIT_INODE_NOEVAL) {
>  		name->fcap_ver = -1;
>  		return;
> @@ -2266,14 +2253,11 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
>  void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
>  {
>  	struct audit_context *context = audit_context();
> -	struct lsmblob blob;
>  	context->ipc.uid = ipcp->uid;
>  	context->ipc.gid = ipcp->gid;
>  	context->ipc.mode = ipcp->mode;
>  	context->ipc.has_perm = 0;
> -	security_ipc_getsecid(ipcp, &blob);
> -	/* scaffolding on the [0] - change "osid" to a lsmblob */
> -	context->ipc.osid = blob.secid[0];
> +	security_ipc_getsecid(ipcp, &context->ipc.olsm);
>  	context->type = AUDIT_IPC;
>  }
>  
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 22/24] LSM: Return the lsmblob slot on initialization
  2019-06-21 18:52 ` [PATCH v3 22/24] LSM: Return the lsmblob slot on initialization Casey Schaufler
@ 2019-06-22 23:13   ` Kees Cook
  2019-06-24 21:39     ` John Johansen
  2019-06-24 21:47   ` John Johansen
  1 sibling, 1 reply; 81+ messages in thread
From: Kees Cook @ 2019-06-22 23:13 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:31AM -0700, Casey Schaufler wrote:
> Return the slot allocated to the calling LSM in the lsmblob
> structure. This can be used to set lsmblobs explicitly for
> netlabel interfaces.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

(I have some thoughts on refactoring the slot assignment, but that
should happen after this series -- it's nothing more than a storage
optimization.)

-Kees

> ---
>  include/linux/lsm_hooks.h  | 4 ++--
>  security/apparmor/lsm.c    | 8 ++++++--
>  security/security.c        | 9 +++++++--
>  security/selinux/hooks.c   | 5 ++++-
>  security/smack/smack_lsm.c | 5 ++++-
>  5 files changed, 23 insertions(+), 8 deletions(-)
> 
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index 4d1ddf1a2aa6..ce341bcbce5d 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -2068,8 +2068,8 @@ struct lsm_blob_sizes {
>  extern struct security_hook_heads security_hook_heads;
>  extern char *lsm_names;
>  
> -extern void security_add_hooks(struct security_hook_list *hooks, int count,
> -				char *lsm);
> +extern int security_add_hooks(struct security_hook_list *hooks, int count,
> +			      char *lsm);
>  
>  #define LSM_FLAG_LEGACY_MAJOR	BIT(0)
>  #define LSM_FLAG_EXCLUSIVE	BIT(1)
> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
> index 2716e7731279..dcbbefbd95ff 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -47,6 +47,9 @@
>  /* Flag indicating whether initialization completed */
>  int apparmor_initialized;
>  
> +/* Slot for the AppArmor secid in the lsmblob structure */
> +int apparmor_lsmblob_slot;
> +
>  DEFINE_PER_CPU(struct aa_buffers, aa_buffers);
>  
>  
> @@ -1678,8 +1681,9 @@ static int __init apparmor_init(void)
>  		aa_free_root_ns();
>  		goto buffers_out;
>  	}
> -	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
> -				"apparmor");
> +	apparmor_lsmblob_slot = security_add_hooks(apparmor_hooks,
> +						   ARRAY_SIZE(apparmor_hooks),
> +						   "apparmor");
>  
>  	/* Report that AppArmor successfully initialized */
>  	apparmor_initialized = 1;
> diff --git a/security/security.c b/security/security.c
> index b2ffcd1f3057..c93a368b697b 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -437,9 +437,12 @@ static int lsm_slot __initdata;
>   * Each LSM has to register its hooks with the infrastructure.
>   * If the LSM is using hooks that export secids allocate a slot
>   * for it in the lsmblob.
> + *
> + * Returns the slot number in the lsmblob structure if one is
> + * allocated or LSMBLOB_INVALID if one was not allocated.
>   */
> -void __init security_add_hooks(struct security_hook_list *hooks, int count,
> -				char *lsm)
> +int __init security_add_hooks(struct security_hook_list *hooks, int count,
> +			      char *lsm)
>  {
>  	int slot = LSMBLOB_INVALID;
>  	int i;
> @@ -479,6 +482,8 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
>  	}
>  	if (lsm_append(lsm, &lsm_names) < 0)
>  		panic("%s - Cannot get early memory.\n", __func__);
> +
> +	return slot;
>  }
>  
>  int call_lsm_notifier(enum lsm_event event, void *data)
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index ee840fecfebb..1e09acbf9630 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -103,6 +103,7 @@
>  #include "avc_ss.h"
>  
>  struct selinux_state selinux_state;
> +int selinux_lsmblob_slot;
>  
>  /* SECMARK reference count */
>  static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
> @@ -6877,7 +6878,9 @@ static __init int selinux_init(void)
>  
>  	hashtab_cache_init();
>  
> -	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
> +	selinux_lsmblob_slot = security_add_hooks(selinux_hooks,
> +						  ARRAY_SIZE(selinux_hooks),
> +						  "selinux");
>  
>  	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
>  		panic("SELinux: Unable to register AVC netcache callback\n");
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 3834b751d1e9..273f311fb153 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -60,6 +60,7 @@ static LIST_HEAD(smk_ipv6_port_list);
>  #endif
>  static struct kmem_cache *smack_inode_cache;
>  int smack_enabled;
> +int smack_lsmblob_slot;
>  
>  #define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
>  static struct {
> @@ -4749,7 +4750,9 @@ static __init int smack_init(void)
>  	/*
>  	 * Register with LSM
>  	 */
> -	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
> +	smack_lsmblob_slot = security_add_hooks(smack_hooks,
> +						ARRAY_SIZE(smack_hooks),
> +						"smack");
>  	smack_enabled = 1;
>  
>  	pr_info("Smack:  Initializing.\n");
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 23/24] NET: Store LSM netlabel data in a lsmblob
  2019-06-21 18:52 ` [PATCH v3 23/24] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
@ 2019-06-22 23:15   ` Kees Cook
  2019-06-24 21:44   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 23:15 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:32AM -0700, Casey Schaufler wrote:
> Netlabel uses LSM interfaces requiring an lsmblob and
> the internal storage is used to pass information between
> these interfaces, so change the internal data from a secid
> to a lsmblob. Update the netlabel interfaces and their
> callers to accomodate the change.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  include/net/netlabel.h              |  8 ++--
>  net/ipv4/cipso_ipv4.c               |  6 ++-
>  net/netlabel/netlabel_kapi.c        |  6 +--
>  net/netlabel/netlabel_unlabeled.c   | 57 +++++++++++------------------
>  net/netlabel/netlabel_unlabeled.h   |  2 +-
>  security/selinux/include/security.h |  1 +
>  security/selinux/netlabel.c         |  2 +-
>  security/selinux/ss/services.c      |  4 +-
>  security/smack/smack.h              |  1 +
>  security/smack/smack_lsm.c          |  3 +-
>  security/smack/smackfs.c            | 10 +++--
>  11 files changed, 48 insertions(+), 52 deletions(-)
> 
> diff --git a/include/net/netlabel.h b/include/net/netlabel.h
> index 72d6435fc16c..6c550455e69f 100644
> --- a/include/net/netlabel.h
> +++ b/include/net/netlabel.h
> @@ -180,7 +180,7 @@ struct netlbl_lsm_catmap {
>   * @attr.mls: MLS sensitivity label
>   * @attr.mls.cat: MLS category bitmap
>   * @attr.mls.lvl: MLS sensitivity level
> - * @attr.secid: LSM specific secid token
> + * @attr.lsmblob: LSM specific data
>   *
>   * Description:
>   * This structure is used to pass security attributes between NetLabel and the
> @@ -215,7 +215,7 @@ struct netlbl_lsm_secattr {
>  			struct netlbl_lsm_catmap *cat;
>  			u32 lvl;
>  		} mls;
> -		u32 secid;
> +		struct lsmblob lsmblob;
>  	} attr;
>  };
>  
> @@ -429,7 +429,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
>  				const void *addr,
>  				const void *mask,
>  				u16 family,
> -				u32 secid,
> +				struct lsmblob *lsmblob,
>  				struct netlbl_audit *audit_info);
>  int netlbl_cfg_unlbl_static_del(struct net *net,
>  				const char *dev_name,
> @@ -537,7 +537,7 @@ static inline int netlbl_cfg_unlbl_static_add(struct net *net,
>  					      const void *addr,
>  					      const void *mask,
>  					      u16 family,
> -					      u32 secid,
> +					      struct lsmblob *lsmblob,
>  					      struct netlbl_audit *audit_info)
>  {
>  	return -ENOSYS;
> diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
> index f0165c5f376b..eb4939f38a14 100644
> --- a/net/ipv4/cipso_ipv4.c
> +++ b/net/ipv4/cipso_ipv4.c
> @@ -1481,7 +1481,8 @@ static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
>  
>  	buffer[0] = CIPSO_V4_TAG_LOCAL;
>  	buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
> -	*(u32 *)&buffer[2] = secattr->attr.secid;
> +	/* only one netlabel user - the first */
> +	*(u32 *)&buffer[2] = secattr->attr.lsmblob.secid[0];
>  
>  	return CIPSO_V4_TAG_LOC_BLEN;
>  }
> @@ -1501,7 +1502,8 @@ static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
>  				 const unsigned char *tag,
>  				 struct netlbl_lsm_secattr *secattr)
>  {
> -	secattr->attr.secid = *(u32 *)&tag[2];
> +	/* only one netlabel user - the first */
> +	secattr->attr.lsmblob.secid[0] = *(u32 *)&tag[2];
>  	secattr->flags |= NETLBL_SECATTR_SECID;
>  
>  	return 0;
> diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
> index ee3e5b6471a6..724d44943543 100644
> --- a/net/netlabel/netlabel_kapi.c
> +++ b/net/netlabel/netlabel_kapi.c
> @@ -210,7 +210,7 @@ int netlbl_cfg_unlbl_map_add(const char *domain,
>   * @addr: IP address in network byte order (struct in[6]_addr)
>   * @mask: address mask in network byte order (struct in[6]_addr)
>   * @family: address family
> - * @secid: LSM secid value for the entry
> + * @lsmblob: LSM data value for the entry
>   * @audit_info: NetLabel audit information
>   *
>   * Description:
> @@ -224,7 +224,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
>  				const void *addr,
>  				const void *mask,
>  				u16 family,
> -				u32 secid,
> +				struct lsmblob *lsmblob,
>  				struct netlbl_audit *audit_info)
>  {
>  	u32 addr_len;
> @@ -244,7 +244,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
>  
>  	return netlbl_unlhsh_add(net,
>  				 dev_name, addr, mask, addr_len,
> -				 secid, audit_info);
> +				 lsmblob, audit_info);
>  }
>  
>  /**
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 4716e0011ba5..57ede7781c8f 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -80,7 +80,7 @@ struct netlbl_unlhsh_tbl {
>  #define netlbl_unlhsh_addr4_entry(iter) \
>  	container_of(iter, struct netlbl_unlhsh_addr4, list)
>  struct netlbl_unlhsh_addr4 {
> -	u32 secid;
> +	struct lsmblob lsmblob;
>  
>  	struct netlbl_af4list list;
>  	struct rcu_head rcu;
> @@ -88,7 +88,7 @@ struct netlbl_unlhsh_addr4 {
>  #define netlbl_unlhsh_addr6_entry(iter) \
>  	container_of(iter, struct netlbl_unlhsh_addr6, list)
>  struct netlbl_unlhsh_addr6 {
> -	u32 secid;
> +	struct lsmblob lsmblob;
>  
>  	struct netlbl_af6list list;
>  	struct rcu_head rcu;
> @@ -233,7 +233,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
>   * @iface: the associated interface entry
>   * @addr: IPv4 address in network byte order
>   * @mask: IPv4 address mask in network byte order
> - * @secid: LSM secid value for entry
> + * @lsmblob: LSM data value for entry
>   *
>   * Description:
>   * Add a new address entry into the unlabeled connection hash table using the
> @@ -244,7 +244,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
>  static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
>  				   const struct in_addr *addr,
>  				   const struct in_addr *mask,
> -				   u32 secid)
> +				   struct lsmblob *lsmblob)
>  {
>  	int ret_val;
>  	struct netlbl_unlhsh_addr4 *entry;
> @@ -256,7 +256,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
>  	entry->list.addr = addr->s_addr & mask->s_addr;
>  	entry->list.mask = mask->s_addr;
>  	entry->list.valid = 1;
> -	entry->secid = secid;
> +	entry->lsmblob = *lsmblob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
>  	ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);
> @@ -273,7 +273,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
>   * @iface: the associated interface entry
>   * @addr: IPv6 address in network byte order
>   * @mask: IPv6 address mask in network byte order
> - * @secid: LSM secid value for entry
> + * @lsmblob: LSM data value for entry
>   *
>   * Description:
>   * Add a new address entry into the unlabeled connection hash table using the
> @@ -284,7 +284,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
>  static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
>  				   const struct in6_addr *addr,
>  				   const struct in6_addr *mask,
> -				   u32 secid)
> +				   struct lsmblob *lsmblob)
>  {
>  	int ret_val;
>  	struct netlbl_unlhsh_addr6 *entry;
> @@ -300,7 +300,7 @@ static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
>  	entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
>  	entry->list.mask = *mask;
>  	entry->list.valid = 1;
> -	entry->secid = secid;
> +	entry->lsmblob = *lsmblob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
>  	ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);
> @@ -379,7 +379,7 @@ int netlbl_unlhsh_add(struct net *net,
>  		      const void *addr,
>  		      const void *mask,
>  		      u32 addr_len,
> -		      u32 secid,
> +		      struct lsmblob *lsmblob,
>  		      struct netlbl_audit *audit_info)
>  {
>  	int ret_val;
> @@ -388,7 +388,6 @@ int netlbl_unlhsh_add(struct net *net,
>  	struct netlbl_unlhsh_iface *iface;
>  	struct audit_buffer *audit_buf = NULL;
>  	struct lsmcontext context;
> -	struct lsmblob blob;
>  
>  	if (addr_len != sizeof(struct in_addr) &&
>  	    addr_len != sizeof(struct in6_addr))
> @@ -421,7 +420,7 @@ int netlbl_unlhsh_add(struct net *net,
>  		const struct in_addr *addr4 = addr;
>  		const struct in_addr *mask4 = mask;
>  
> -		ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
> +		ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, lsmblob);
>  		if (audit_buf != NULL)
>  			netlbl_af4list_audit_addr(audit_buf, 1,
>  						  dev_name,
> @@ -434,7 +433,7 @@ int netlbl_unlhsh_add(struct net *net,
>  		const struct in6_addr *addr6 = addr;
>  		const struct in6_addr *mask6 = mask;
>  
> -		ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
> +		ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, lsmblob);
>  		if (audit_buf != NULL)
>  			netlbl_af6list_audit_addr(audit_buf, 1,
>  						  dev_name,
> @@ -451,8 +450,7 @@ int netlbl_unlhsh_add(struct net *net,
>  unlhsh_add_return:
>  	rcu_read_unlock();
>  	if (audit_buf != NULL) {
> -		lsmblob_init(&blob, secid);
> -		if (security_secid_to_secctx(&blob, &context) == 0) {
> +		if (security_secid_to_secctx(lsmblob, &context) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s",
>  					 context.context);
>  			security_release_secctx(&context);
> @@ -487,7 +485,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  	struct audit_buffer *audit_buf;
>  	struct net_device *dev;
>  	struct lsmcontext context;
> -	struct lsmblob blob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
>  	list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
> @@ -507,10 +504,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  					  addr->s_addr, mask->s_addr);
>  		if (dev != NULL)
>  			dev_put(dev);
> -		if (entry != NULL)
> -			lsmblob_init(&blob, entry->secid);
>  		if (entry != NULL &&
> -		    security_secid_to_secctx(&blob, &context) == 0) {
> +		    security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s",
>  					 context.context);
>  			security_release_secctx(&context);
> @@ -551,7 +546,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  	struct audit_buffer *audit_buf;
>  	struct net_device *dev;
>  	struct lsmcontext context;
> -	struct lsmblob blob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
>  	list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
> @@ -570,10 +564,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  					  addr, mask);
>  		if (dev != NULL)
>  			dev_put(dev);
> -		if (entry != NULL)
> -			lsmblob_init(&blob, entry->secid);
>  		if (entry != NULL &&
> -		    security_secid_to_secctx(&blob, &context) == 0) {
> +		    security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s",
>  					 context.context);
>  			security_release_secctx(&context);
> @@ -927,9 +919,8 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
>  	if (ret_val != 0)
>  		return ret_val;
>  
> -	/* scaffolding with the [0] */
>  	return netlbl_unlhsh_add(&init_net,
> -				 dev_name, addr, mask, addr_len, blob.secid[0],
> +				 dev_name, addr, mask, addr_len, &blob,
>  				 &audit_info);
>  }
>  
> @@ -977,10 +968,8 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
>  	if (ret_val != 0)
>  		return ret_val;
>  
> -	/* scaffolding with the [0] */
>  	return netlbl_unlhsh_add(&init_net,
> -				 NULL, addr, mask, addr_len, blob.secid[0],
> -				 &audit_info);
> +				 NULL, addr, mask, addr_len, &blob, &audit_info);
>  }
>  
>  /**
> @@ -1092,8 +1081,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  	struct net_device *dev;
>  	struct lsmcontext context;
>  	void *data;
> -	u32 secid;
> -	struct lsmblob blob;
> +	struct lsmblob *lsmb;
>  
>  	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
>  			   cb_arg->seq, &netlbl_unlabel_gnl_family,
> @@ -1131,7 +1119,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  		if (ret_val != 0)
>  			goto list_cb_failure;
>  
> -		secid = addr4->secid;
> +		lsmb = (struct lsmblob *)&addr4->lsmblob;
>  	} else {
>  		ret_val = nla_put_in6_addr(cb_arg->skb,
>  					   NLBL_UNLABEL_A_IPV6ADDR,
> @@ -1145,11 +1133,10 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  		if (ret_val != 0)
>  			goto list_cb_failure;
>  
> -		secid = addr6->secid;
> +		lsmb = (struct lsmblob *)&addr6->lsmblob;
>  	}
>  
> -	lsmblob_init(&blob, secid);
> -	ret_val = security_secid_to_secctx(&blob, &context);
> +	ret_val = security_secid_to_secctx(lsmb, &context);
>  	if (ret_val != 0)
>  		goto list_cb_failure;
>  	ret_val = nla_put(cb_arg->skb,
> @@ -1500,7 +1487,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
>  					      &iface->addr4_list);
>  		if (addr4 == NULL)
>  			goto unlabel_getattr_nolabel;
> -		secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;
> +		secattr->attr.lsmblob = netlbl_unlhsh_addr4_entry(addr4)->lsmblob;
>  		break;
>  	}
>  #if IS_ENABLED(CONFIG_IPV6)
> @@ -1513,7 +1500,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
>  					      &iface->addr6_list);
>  		if (addr6 == NULL)
>  			goto unlabel_getattr_nolabel;
> -		secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;
> +		secattr->attr.lsmblob = netlbl_unlhsh_addr6_entry(addr6)->lsmblob;
>  		break;
>  	}
>  #endif /* IPv6 */
> diff --git a/net/netlabel/netlabel_unlabeled.h b/net/netlabel/netlabel_unlabeled.h
> index 3a9e5dc9511b..dcff99695c97 100644
> --- a/net/netlabel/netlabel_unlabeled.h
> +++ b/net/netlabel/netlabel_unlabeled.h
> @@ -225,7 +225,7 @@ int netlbl_unlhsh_add(struct net *net,
>  		      const void *addr,
>  		      const void *mask,
>  		      u32 addr_len,
> -		      u32 secid,
> +		      struct lsmblob *lsmblob,
>  		      struct netlbl_audit *audit_info);
>  int netlbl_unlhsh_remove(struct net *net,
>  			 const char *dev_name,
> diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
> index b5b7c5aade8c..94787988c8fb 100644
> --- a/security/selinux/include/security.h
> +++ b/security/selinux/include/security.h
> @@ -68,6 +68,7 @@
>  struct netlbl_lsm_secattr;
>  
>  extern int selinux_enabled;
> +extern int selinux_lsmblob_slot;
>  
>  /* Policy capabilities */
>  enum {
> diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
> index c40914a157b7..320a4cdc657e 100644
> --- a/security/selinux/netlabel.c
> +++ b/security/selinux/netlabel.c
> @@ -122,7 +122,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
>  		return NULL;
>  
>  	if ((secattr->flags & NETLBL_SECATTR_SECID) &&
> -	    (secattr->attr.secid == sid))
> +	    (secattr->attr.lsmblob.secid[selinux_lsmblob_slot] == sid))
>  		return secattr;
>  
>  	return NULL;
> diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
> index e3f5d6aece66..a3be1afafd7f 100644
> --- a/security/selinux/ss/services.c
> +++ b/security/selinux/ss/services.c
> @@ -3593,7 +3593,7 @@ int security_netlbl_secattr_to_sid(struct selinux_state *state,
>  	if (secattr->flags & NETLBL_SECATTR_CACHE)
>  		*sid = *(u32 *)secattr->cache->data;
>  	else if (secattr->flags & NETLBL_SECATTR_SECID)
> -		*sid = secattr->attr.secid;
> +		*sid = secattr->attr.lsmblob.secid[selinux_lsmblob_slot];
>  	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
>  		rc = -EIDRM;
>  		ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
> @@ -3666,7 +3666,7 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state,
>  	if (secattr->domain == NULL)
>  		goto out;
>  
> -	secattr->attr.secid = sid;
> +	secattr->attr.lsmblob.secid[selinux_lsmblob_slot] = sid;
>  	secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
>  	mls_export_netlbl_lvl(policydb, ctx, secattr);
>  	rc = mls_export_netlbl_cat(policydb, ctx, secattr);
> diff --git a/security/smack/smack.h b/security/smack/smack.h
> index 7cc3a3382fee..097ffde7f202 100644
> --- a/security/smack/smack.h
> +++ b/security/smack/smack.h
> @@ -320,6 +320,7 @@ void smk_destroy_label_list(struct list_head *list);
>   * Shared data.
>   */
>  extern int smack_enabled;
> +extern int smack_lsmblob_slot;
>  extern int smack_cipso_direct;
>  extern int smack_cipso_mapped;
>  extern struct smack_known *smack_net_ambient;
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 273f311fb153..b83aba0f2013 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -3742,7 +3742,8 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
>  		/*
>  		 * Looks like a fallback, which gives us a secid.
>  		 */
> -		return smack_from_secid(sap->attr.secid);
> +		return smack_from_secid(
> +				sap->attr.lsmblob.secid[smack_lsmblob_slot]);
>  	/*
>  	 * Without guidance regarding the smack value
>  	 * for the packet fall back on the network
> diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
> index faf2ea3968b3..066d53c29ed4 100644
> --- a/security/smack/smackfs.c
> +++ b/security/smack/smackfs.c
> @@ -1150,6 +1150,7 @@ static void smk_net4addr_insert(struct smk_net4addr *new)
>  static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
>  				size_t count, loff_t *ppos)
>  {
> +	struct lsmblob lsmblob;
>  	struct smk_net4addr *snp;
>  	struct sockaddr_in newname;
>  	char *smack;
> @@ -1281,10 +1282,13 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
>  	 * this host so that incoming packets get labeled.
>  	 * but only if we didn't get the special CIPSO option
>  	 */
> -	if (rc == 0 && skp != NULL)
> +	if (rc == 0 && skp != NULL) {
> +		lsmblob_init(&lsmblob, 0);
> +		lsmblob.secid[smack_lsmblob_slot] = snp->smk_label->smk_secid;
>  		rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
> -			&snp->smk_host, &snp->smk_mask, PF_INET,
> -			snp->smk_label->smk_secid, &audit_info);
> +			&snp->smk_host, &snp->smk_mask, PF_INET, &lsmblob,
> +			&audit_info);
> +	}
>  
>  	if (rc == 0)
>  		rc = count;
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 24/24] AppArmor: Remove the exclusive flag
  2019-06-21 18:52 ` [PATCH v3 24/24] AppArmor: Remove the exclusive flag Casey Schaufler
@ 2019-06-22 23:15   ` Kees Cook
  2019-06-24 21:45   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-22 23:15 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Fri, Jun 21, 2019 at 11:52:33AM -0700, Casey Schaufler wrote:
> With the inclusion of the "display" process attribute
> mechanism AppArmor no longer needs to be treated as an
> "exclusive" security module. Remove the flag that indicates
> it is exclusive. Remove the stub getpeersec_dgram AppArmor
> hook as it has no effect in the single LSM case and
> interferes in the multiple LSM case.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  security/apparmor/lsm.c | 20 +-------------------
>  1 file changed, 1 insertion(+), 19 deletions(-)
> 
> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
> index dcbbefbd95ff..c4365434f10b 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -1082,22 +1082,6 @@ static int apparmor_socket_getpeersec_stream(struct socket *sock,
>  	return error;
>  }
>  
> -/**
> - * apparmor_socket_getpeersec_dgram - get security label of packet
> - * @sock: the peer socket
> - * @skb: packet data
> - * @secid: pointer to where to put the secid of the packet
> - *
> - * Sets the netlabel socket state on sk from parent
> - */
> -static int apparmor_socket_getpeersec_dgram(struct socket *sock,
> -					    struct sk_buff *skb, u32 *secid)
> -
> -{
> -	/* TODO: requires secid support */
> -	return -ENOPROTOOPT;
> -}
> -
>  /**
>   * apparmor_sock_graft - Initialize newly created socket
>   * @sk: child sock
> @@ -1196,8 +1180,6 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
>  #endif
>  	LSM_HOOK_INIT(socket_getpeersec_stream,
>  		      apparmor_socket_getpeersec_stream),
> -	LSM_HOOK_INIT(socket_getpeersec_dgram,
> -		      apparmor_socket_getpeersec_dgram),
>  	LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
>  #ifdef CONFIG_NETWORK_SECMARK
>  	LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
> @@ -1709,7 +1691,7 @@ static int __init apparmor_init(void)
>  
>  DEFINE_LSM(apparmor) = {
>  	.name = "apparmor",
> -	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
> +	.flags = LSM_FLAG_LEGACY_MAJOR,
>  	.enabled = &apparmor_enabled,
>  	.blobs = &apparmor_blob_sizes,
>  	.init = apparmor_init,
> -- 
> 2.20.1
> 

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 10/24] Use lsmblob in security_ipc_getsecid
  2019-06-22 22:48   ` Kees Cook
@ 2019-06-24 16:39     ` Casey Schaufler
  2019-06-24 17:20       ` Casey Schaufler
  2019-06-24 21:09       ` Kees Cook
  0 siblings, 2 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-24 16:39 UTC (permalink / raw)
  To: Kees Cook
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On 6/22/2019 3:48 PM, Kees Cook wrote:
> On Fri, Jun 21, 2019 at 11:52:19AM -0700, Casey Schaufler wrote:
>> There may be more than one LSM that provides IPC data
>> for auditing. Change security_ipc_getsecid() to fill in
>> a lsmblob structure instead of the u32 secid. The
>> audit data structure containing the secid will be updated
>> later, so there is a bit of scaffolding here.
>>
>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> Reviewed-by: Kees Cook <keescook@chromium.org>
>
> One thought below...
>
>> ---
>>  include/linux/security.h | 7 ++++---
>>  kernel/auditsc.c         | 5 ++++-
>>  security/security.c      | 9 ++++++---
>>  3 files changed, 14 insertions(+), 7 deletions(-)
>>
>> diff --git a/include/linux/security.h b/include/linux/security.h
>> index c6cddeff8a17..0d5e172341fc 100644
>> --- a/include/linux/security.h
>> +++ b/include/linux/security.h
>> @@ -413,7 +413,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
>>  			unsigned long arg4, unsigned long arg5);
>>  void security_task_to_inode(struct task_struct *p, struct inode *inode);
>>  int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
>> -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid);
>> +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob);
>>  int security_msg_msg_alloc(struct msg_msg *msg);
>>  void security_msg_msg_free(struct msg_msg *msg);
>>  int security_msg_queue_alloc(struct kern_ipc_perm *msq);
>> @@ -1098,9 +1098,10 @@ static inline int security_ipc_permission(struct kern_ipc_perm *ipcp,
>>  	return 0;
>>  }
>>  
>> -static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
>> +static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp,
>> +					 struct lsmblob *blob)
>>  {
>> -	*secid = 0;
>> +	lsmblob_init(blob, 0);
>>  }
>>  
>>  static inline int security_msg_msg_alloc(struct msg_msg *msg)
>> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
>> index d31914088a82..148733ec3c72 100644
>> --- a/kernel/auditsc.c
>> +++ b/kernel/auditsc.c
>> @@ -2268,11 +2268,14 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
>>  void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
>>  {
>>  	struct audit_context *context = audit_context();
>> +	struct lsmblob blob;
>>  	context->ipc.uid = ipcp->uid;
>>  	context->ipc.gid = ipcp->gid;
>>  	context->ipc.mode = ipcp->mode;
>>  	context->ipc.has_perm = 0;
>> -	security_ipc_getsecid(ipcp, &context->ipc.osid);
>> +	security_ipc_getsecid(ipcp, &blob);
>> +	/* scaffolding on the [0] - change "osid" to a lsmblob */
>> +	context->ipc.osid = blob.secid[0];
>>  	context->type = AUDIT_IPC;
>>  }
>>  
>> diff --git a/security/security.c b/security/security.c
>> index 5ab07631df75..d55f01041f05 100644
>> --- a/security/security.c
>> +++ b/security/security.c
>> @@ -1812,10 +1812,13 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
>>  	return call_int_hook(ipc_permission, 0, ipcp, flag);
>>  }
>>  
>> -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
>> +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob)
>>  {
>> -	*secid = 0;
>> -	call_void_hook(ipc_getsecid, ipcp, secid);
>> +	struct security_hook_list *hp;
>> +
>> +	lsmblob_init(blob, 0);
>> +	hlist_for_each_entry(hp, &security_hook_heads.ipc_getsecid, list)
>> +		hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->slot]);
> Just for sanity when using hp->slot, it might be good to do something
> like this in the places it gets used. Like for here:
>
> 	if (!WARN_ON(hp->slot < 0 || hp->slot >= LSMBLOB_COUNT))
> 		hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->slot]);
>
> This _should_ be overkill, but since lists of hooks that trigger slot
> assignment is hardcoded, it seems nice to cover any future problems or
> mismatches.

How about a CONFIG_LSM_SLOT_CHECK around a function lsm_slot_check()?
If configured, it does the WARN_ON, and if not it's a static inline
true return. As you say, it's probably overkill, but it would be available
for the paranoid/debug/bringup situation.



^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 10/24] Use lsmblob in security_ipc_getsecid
  2019-06-24 16:39     ` Casey Schaufler
@ 2019-06-24 17:20       ` Casey Schaufler
  2019-06-24 21:09       ` Kees Cook
  1 sibling, 0 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-24 17:20 UTC (permalink / raw)
  To: Kees Cook
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds, casey

On 6/24/2019 9:39 AM, Casey Schaufler wrote:
> On 6/22/2019 3:48 PM, Kees Cook wrote:
>> On Fri, Jun 21, 2019 at 11:52:19AM -0700, Casey Schaufler wrote:
>>> There may be more than one LSM that provides IPC data
>>> for auditing. Change security_ipc_getsecid() to fill in
>>> a lsmblob structure instead of the u32 secid. The
>>> audit data structure containing the secid will be updated
>>> later, so there is a bit of scaffolding here.
>>>
>>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>> Reviewed-by: Kees Cook <keescook@chromium.org>
>>
>> One thought below...
>>
>>> ---
>>>  include/linux/security.h | 7 ++++---
>>>  kernel/auditsc.c         | 5 ++++-
>>>  security/security.c      | 9 ++++++---
>>>  3 files changed, 14 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/include/linux/security.h b/include/linux/security.h
>>> index c6cddeff8a17..0d5e172341fc 100644
>>> --- a/include/linux/security.h
>>> +++ b/include/linux/security.h
>>> @@ -413,7 +413,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
>>>  			unsigned long arg4, unsigned long arg5);
>>>  void security_task_to_inode(struct task_struct *p, struct inode *inode);
>>>  int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
>>> -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid);
>>> +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob);
>>>  int security_msg_msg_alloc(struct msg_msg *msg);
>>>  void security_msg_msg_free(struct msg_msg *msg);
>>>  int security_msg_queue_alloc(struct kern_ipc_perm *msq);
>>> @@ -1098,9 +1098,10 @@ static inline int security_ipc_permission(struct kern_ipc_perm *ipcp,
>>>  	return 0;
>>>  }
>>>  
>>> -static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
>>> +static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp,
>>> +					 struct lsmblob *blob)
>>>  {
>>> -	*secid = 0;
>>> +	lsmblob_init(blob, 0);
>>>  }
>>>  
>>>  static inline int security_msg_msg_alloc(struct msg_msg *msg)
>>> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
>>> index d31914088a82..148733ec3c72 100644
>>> --- a/kernel/auditsc.c
>>> +++ b/kernel/auditsc.c
>>> @@ -2268,11 +2268,14 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
>>>  void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
>>>  {
>>>  	struct audit_context *context = audit_context();
>>> +	struct lsmblob blob;
>>>  	context->ipc.uid = ipcp->uid;
>>>  	context->ipc.gid = ipcp->gid;
>>>  	context->ipc.mode = ipcp->mode;
>>>  	context->ipc.has_perm = 0;
>>> -	security_ipc_getsecid(ipcp, &context->ipc.osid);
>>> +	security_ipc_getsecid(ipcp, &blob);
>>> +	/* scaffolding on the [0] - change "osid" to a lsmblob */
>>> +	context->ipc.osid = blob.secid[0];
>>>  	context->type = AUDIT_IPC;
>>>  }
>>>  
>>> diff --git a/security/security.c b/security/security.c
>>> index 5ab07631df75..d55f01041f05 100644
>>> --- a/security/security.c
>>> +++ b/security/security.c
>>> @@ -1812,10 +1812,13 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
>>>  	return call_int_hook(ipc_permission, 0, ipcp, flag);
>>>  }
>>>  
>>> -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
>>> +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob)
>>>  {
>>> -	*secid = 0;
>>> -	call_void_hook(ipc_getsecid, ipcp, secid);
>>> +	struct security_hook_list *hp;
>>> +
>>> +	lsmblob_init(blob, 0);
>>> +	hlist_for_each_entry(hp, &security_hook_heads.ipc_getsecid, list)
>>> +		hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->slot]);
>> Just for sanity when using hp->slot, it might be good to do something
>> like this in the places it gets used. Like for here:
>>
>> 	if (!WARN_ON(hp->slot < 0 || hp->slot >= LSMBLOB_COUNT))
>> 		hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->slot]);
>>
>> This _should_ be overkill, but since lists of hooks that trigger slot
>> assignment is hardcoded, it seems nice to cover any future problems or
>> mismatches.
> How about a CONFIG_LSM_SLOT_CHECK around a function lsm_slot_check()?
> If configured, it does the WARN_ON, and if not it's a static inline
> true return. As you say, it's probably overkill, but it would be available
> for the paranoid/debug/bringup situation.

... or maybe it would be better if security_add_hooks() had an
explicit parameter whereby an LSM can tell the infrastructure that
it wants a slot. The only future problems would come if the LSM
writer got the parameter wrong or if secid dependence got added
to an existing interface and a LSM that didn't used to need a 
slot suddenly did. I don't see either of those as compelling.



^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 01/24] LSM: Infrastructure management of the superblock
  2019-06-21 18:52 ` [PATCH v3 01/24] LSM: Infrastructure management of the superblock Casey Schaufler
@ 2019-06-24 18:31   ` John Johansen
  0 siblings, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:31 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Move management of the superblock->sb_security blob out
> of the individual security modules and into the security
> infrastructure. Instead of allocating the blobs from within
> the modules the modules tell the infrastructure how much
> space is required, and the space is allocated there.
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

with small fix below

Reviewed-by:John Johansen <john.johansen@canonical.com>

> ---
>  include/linux/lsm_hooks.h         |  1 +
>  security/security.c               | 46 ++++++++++++++++++++----
>  security/selinux/hooks.c          | 58 ++++++++++++-------------------
>  security/selinux/include/objsec.h |  6 ++++
>  security/selinux/ss/services.c    |  3 +-
>  security/smack/smack.h            |  6 ++++
>  security/smack/smack_lsm.c        | 35 +++++--------------
>  7 files changed, 85 insertions(+), 70 deletions(-)
> 
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index a240a3fc5fc4..f9222a04968d 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -2047,6 +2047,7 @@ struct lsm_blob_sizes {
>  	int	lbs_cred;
>  	int	lbs_file;
>  	int	lbs_inode;
> +	int	lbs_superblock;
>  	int	lbs_ipc;
>  	int	lbs_msg_msg;
>  	int	lbs_task;
> diff --git a/security/security.c b/security/security.c
> index 23cbb1a295a3..550988a0f024 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -172,6 +172,7 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed)
>  	lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode);
>  	lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc);
>  	lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg);
> +	lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock);
>  	lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task);
>  }
>  
> @@ -300,12 +301,13 @@ static void __init ordered_lsm_init(void)
>  	for (lsm = ordered_lsms; *lsm; lsm++)
>  		prepare_lsm(*lsm);
>  
> -	init_debug("cred blob size     = %d\n", blob_sizes.lbs_cred);
> -	init_debug("file blob size     = %d\n", blob_sizes.lbs_file);
> -	init_debug("inode blob size    = %d\n", blob_sizes.lbs_inode);
> -	init_debug("ipc blob size      = %d\n", blob_sizes.lbs_ipc);
> -	init_debug("msg_msg blob size  = %d\n", blob_sizes.lbs_msg_msg);
> -	init_debug("task blob size     = %d\n", blob_sizes.lbs_task);
> +	init_debug("cred blob size       = %d\n", blob_sizes.lbs_cred);
> +	init_debug("file blob size       = %d\n", blob_sizes.lbs_file);
> +	init_debug("inode blob size      = %d\n", blob_sizes.lbs_inode);
> +	init_debug("ipc blob size        = %d\n", blob_sizes.lbs_ipc);
> +	init_debug("msg_msg blob size    = %d\n", blob_sizes.lbs_msg_msg);
> +	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
> +	init_debug("task blob size       = %d\n", blob_sizes.lbs_task);
>  
>  	/*
>  	 * Create any kmem_caches needed for blobs
> @@ -603,6 +605,27 @@ static void __init lsm_early_task(struct task_struct *task)
>  		panic("%s: Early task alloc failed.\n", __func__);
>  }
>  
> +/**
> + * lsm_superblock_alloc - allocate a composite superblock blob
> + * @sb: the superblock that needs a blob
> + *
> + * Allocate the superblock blob for all the modules
> + *
> + * Returns 0, or -ENOMEM if memory can't be allocated.
> + */
> +int lsm_superblock_alloc(struct super_block *sb)


should be static


> +{
> +	if (blob_sizes.lbs_superblock == 0) {
> +		sb->s_security = NULL;
> +		return 0;
> +	}
> +
> +	sb->s_security = kzalloc(blob_sizes.lbs_superblock, GFP_KERNEL);
> +	if (sb->s_security == NULL)
> +		return -ENOMEM;
> +	return 0;
> +}
> +
>  /*
>   * Hook list operation macros.
>   *
> @@ -776,12 +799,21 @@ int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *
>  
>  int security_sb_alloc(struct super_block *sb)
>  {
> -	return call_int_hook(sb_alloc_security, 0, sb);
> +	int rc = lsm_superblock_alloc(sb);
> +
> +	if (unlikely(rc))
> +		return rc;
> +	rc = call_int_hook(sb_alloc_security, 0, sb);
> +	if (unlikely(rc))
> +		security_sb_free(sb);
> +	return rc;
>  }
>  
>  void security_sb_free(struct super_block *sb)
>  {
>  	call_void_hook(sb_free_security, sb);
> +	kfree(sb->s_security);
> +	sb->s_security = NULL;
>  }
>  
>  void security_free_mnt_opts(void **mnt_opts)
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 1d0b37af2444..7478d8eda00a 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -335,7 +335,7 @@ static void inode_free_security(struct inode *inode)
>  
>  	if (!isec)
>  		return;
> -	sbsec = inode->i_sb->s_security;
> +	sbsec = selinux_superblock(inode->i_sb);
>  	/*
>  	 * As not all inode security structures are in a list, we check for
>  	 * empty list outside of the lock to make sure that we won't waste
> @@ -366,11 +366,7 @@ static int file_alloc_security(struct file *file)
>  
>  static int superblock_alloc_security(struct super_block *sb)
>  {
> -	struct superblock_security_struct *sbsec;
> -
> -	sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
> -	if (!sbsec)
> -		return -ENOMEM;
> +	struct superblock_security_struct *sbsec = selinux_superblock(sb);
>  
>  	mutex_init(&sbsec->lock);
>  	INIT_LIST_HEAD(&sbsec->isec_head);
> @@ -379,18 +375,10 @@ static int superblock_alloc_security(struct super_block *sb)
>  	sbsec->sid = SECINITSID_UNLABELED;
>  	sbsec->def_sid = SECINITSID_FILE;
>  	sbsec->mntpoint_sid = SECINITSID_UNLABELED;
> -	sb->s_security = sbsec;
>  
>  	return 0;
>  }
>  
> -static void superblock_free_security(struct super_block *sb)
> -{
> -	struct superblock_security_struct *sbsec = sb->s_security;
> -	sb->s_security = NULL;
> -	kfree(sbsec);
> -}
> -
>  struct selinux_mnt_opts {
>  	const char *fscontext, *context, *rootcontext, *defcontext;
>  };
> @@ -507,7 +495,7 @@ static int selinux_is_genfs_special_handling(struct super_block *sb)
>  
>  static int selinux_is_sblabel_mnt(struct super_block *sb)
>  {
> -	struct superblock_security_struct *sbsec = sb->s_security;
> +	struct superblock_security_struct *sbsec = selinux_superblock(sb);
>  
>  	/*
>  	 * IMPORTANT: Double-check logic in this function when adding a new
> @@ -535,7 +523,7 @@ static int selinux_is_sblabel_mnt(struct super_block *sb)
>  
>  static int sb_finish_set_opts(struct super_block *sb)
>  {
> -	struct superblock_security_struct *sbsec = sb->s_security;
> +	struct superblock_security_struct *sbsec = selinux_superblock(sb);
>  	struct dentry *root = sb->s_root;
>  	struct inode *root_inode = d_backing_inode(root);
>  	int rc = 0;
> @@ -648,7 +636,7 @@ static int selinux_set_mnt_opts(struct super_block *sb,
>  				unsigned long *set_kern_flags)
>  {
>  	const struct cred *cred = current_cred();
> -	struct superblock_security_struct *sbsec = sb->s_security;
> +	struct superblock_security_struct *sbsec = selinux_superblock(sb);
>  	struct dentry *root = sbsec->sb->s_root;
>  	struct selinux_mnt_opts *opts = mnt_opts;
>  	struct inode_security_struct *root_isec;
> @@ -881,8 +869,8 @@ static int selinux_set_mnt_opts(struct super_block *sb,
>  static int selinux_cmp_sb_context(const struct super_block *oldsb,
>  				    const struct super_block *newsb)
>  {
> -	struct superblock_security_struct *old = oldsb->s_security;
> -	struct superblock_security_struct *new = newsb->s_security;
> +	struct superblock_security_struct *old = selinux_superblock(oldsb);
> +	struct superblock_security_struct *new = selinux_superblock(newsb);
>  	char oldflags = old->flags & SE_MNTMASK;
>  	char newflags = new->flags & SE_MNTMASK;
>  
> @@ -914,8 +902,9 @@ static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
>  					unsigned long *set_kern_flags)
>  {
>  	int rc = 0;
> -	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
> -	struct superblock_security_struct *newsbsec = newsb->s_security;
> +	const struct superblock_security_struct *oldsbsec =
> +						selinux_superblock(oldsb);
> +	struct superblock_security_struct *newsbsec = selinux_superblock(newsb);
>  
>  	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
>  	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
> @@ -1085,7 +1074,7 @@ static int show_sid(struct seq_file *m, u32 sid)
>  
>  static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
>  {
> -	struct superblock_security_struct *sbsec = sb->s_security;
> +	struct superblock_security_struct *sbsec = selinux_superblock(sb);
>  	int rc;
>  
>  	if (!(sbsec->flags & SE_SBINITIALIZED))
> @@ -1377,7 +1366,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
>  	if (isec->sclass == SECCLASS_FILE)
>  		isec->sclass = inode_mode_to_security_class(inode->i_mode);
>  
> -	sbsec = inode->i_sb->s_security;
> +	sbsec = selinux_superblock(inode->i_sb);
>  	if (!(sbsec->flags & SE_SBINITIALIZED)) {
>  		/* Defer initialization until selinux_complete_init,
>  		   after the initial policy is loaded and the security
> @@ -1767,7 +1756,8 @@ selinux_determine_inode_label(const struct task_security_struct *tsec,
>  				 const struct qstr *name, u16 tclass,
>  				 u32 *_new_isid)
>  {
> -	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
> +	const struct superblock_security_struct *sbsec =
> +						selinux_superblock(dir->i_sb);
>  
>  	if ((sbsec->flags & SE_SBINITIALIZED) &&
>  	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
> @@ -1798,7 +1788,7 @@ static int may_create(struct inode *dir,
>  	int rc;
>  
>  	dsec = inode_security(dir);
> -	sbsec = dir->i_sb->s_security;
> +	sbsec = selinux_superblock(dir->i_sb);
>  
>  	sid = tsec->sid;
>  
> @@ -1947,7 +1937,7 @@ static int superblock_has_perm(const struct cred *cred,
>  	struct superblock_security_struct *sbsec;
>  	u32 sid = cred_sid(cred);
>  
> -	sbsec = sb->s_security;
> +	sbsec = selinux_superblock(sb);
>  	return avc_has_perm(&selinux_state,
>  			    sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
>  }
> @@ -2578,11 +2568,6 @@ static int selinux_sb_alloc_security(struct super_block *sb)
>  	return superblock_alloc_security(sb);
>  }
>  
> -static void selinux_sb_free_security(struct super_block *sb)
> -{
> -	superblock_free_security(sb);
> -}
> -
>  static inline int opt_len(const char *s)
>  {
>  	bool open_quote = false;
> @@ -2653,7 +2638,7 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
>  static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
>  {
>  	struct selinux_mnt_opts *opts = mnt_opts;
> -	struct superblock_security_struct *sbsec = sb->s_security;
> +	struct superblock_security_struct *sbsec = selinux_superblock(sb);
>  	u32 sid;
>  	int rc;
>  
> @@ -2877,7 +2862,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
>  	int rc;
>  	char *context;
>  
> -	sbsec = dir->i_sb->s_security;
> +	sbsec = selinux_superblock(dir->i_sb);
>  
>  	newsid = tsec->create_sid;
>  
> @@ -3115,7 +3100,7 @@ static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
>  		return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
>  	}
>  
> -	sbsec = inode->i_sb->s_security;
> +	sbsec = selinux_superblock(inode->i_sb);
>  	if (!(sbsec->flags & SBLABEL_MNT))
>  		return -EOPNOTSUPP;
>  
> @@ -3296,13 +3281,14 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name,
>  				     const void *value, size_t size, int flags)
>  {
>  	struct inode_security_struct *isec = inode_security_novalidate(inode);
> -	struct superblock_security_struct *sbsec = inode->i_sb->s_security;
> +	struct superblock_security_struct *sbsec;
>  	u32 newsid;
>  	int rc;
>  
>  	if (strcmp(name, XATTR_SELINUX_SUFFIX))
>  		return -EOPNOTSUPP;
>  
> +	sbsec = selinux_superblock(inode->i_sb);
>  	if (!(sbsec->flags & SBLABEL_MNT))
>  		return -EOPNOTSUPP;
>  
> @@ -6647,6 +6633,7 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
>  	.lbs_inode = sizeof(struct inode_security_struct),
>  	.lbs_ipc = sizeof(struct ipc_security_struct),
>  	.lbs_msg_msg = sizeof(struct msg_security_struct),
> +	.lbs_superblock = sizeof(struct superblock_security_struct),
>  };
>  
>  static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
> @@ -6675,7 +6662,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
>  	LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param),
>  
>  	LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
> -	LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),
>  	LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
>  	LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
>  	LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
> diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
> index 231262d8eac9..d08d7e5d2f93 100644
> --- a/security/selinux/include/objsec.h
> +++ b/security/selinux/include/objsec.h
> @@ -188,4 +188,10 @@ static inline struct ipc_security_struct *selinux_ipc(
>  	return ipc->security + selinux_blob_sizes.lbs_ipc;
>  }
>  
> +static inline struct superblock_security_struct *selinux_superblock(
> +					const struct super_block *superblock)
> +{
> +	return superblock->s_security + selinux_blob_sizes.lbs_superblock;
> +}
> +
>  #endif /* _SELINUX_OBJSEC_H_ */
> diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
> index ec62918521b1..e3f5d6aece66 100644
> --- a/security/selinux/ss/services.c
> +++ b/security/selinux/ss/services.c
> @@ -50,6 +50,7 @@
>  #include <linux/audit.h>
>  #include <linux/mutex.h>
>  #include <linux/vmalloc.h>
> +#include <linux/lsm_hooks.h>
>  #include <net/netlabel.h>
>  
>  #include "flask.h"
> @@ -2751,7 +2752,7 @@ int security_fs_use(struct selinux_state *state, struct super_block *sb)
>  	struct sidtab *sidtab;
>  	int rc = 0;
>  	struct ocontext *c;
> -	struct superblock_security_struct *sbsec = sb->s_security;
> +	struct superblock_security_struct *sbsec = selinux_superblock(sb);
>  	const char *fstype = sb->s_type->name;
>  
>  	read_lock(&state->ss->policy_rwlock);
> diff --git a/security/smack/smack.h b/security/smack/smack.h
> index cf52af77d15e..caecbcba9942 100644
> --- a/security/smack/smack.h
> +++ b/security/smack/smack.h
> @@ -375,6 +375,12 @@ static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc)
>  	return ipc->security + smack_blob_sizes.lbs_ipc;
>  }
>  
> +static inline struct superblock_smack *smack_superblock(
> +					const struct super_block *superblock)
> +{
> +	return superblock->s_security + smack_blob_sizes.lbs_superblock;
> +}
> +
>  /*
>   * Is the directory transmuting?
>   */
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 5c1613519d5a..807eff2ccce9 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -540,12 +540,7 @@ static int smack_syslog(int typefrom_file)
>   */
>  static int smack_sb_alloc_security(struct super_block *sb)
>  {
> -	struct superblock_smack *sbsp;
> -
> -	sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
> -
> -	if (sbsp == NULL)
> -		return -ENOMEM;
> +	struct superblock_smack *sbsp = smack_superblock(sb);
>  
>  	sbsp->smk_root = &smack_known_floor;
>  	sbsp->smk_default = &smack_known_floor;
> @@ -554,22 +549,10 @@ static int smack_sb_alloc_security(struct super_block *sb)
>  	/*
>  	 * SMK_SB_INITIALIZED will be zero from kzalloc.
>  	 */
> -	sb->s_security = sbsp;
>  
>  	return 0;
>  }
>  
> -/**
> - * smack_sb_free_security - free a superblock blob
> - * @sb: the superblock getting the blob
> - *
> - */
> -static void smack_sb_free_security(struct super_block *sb)
> -{
> -	kfree(sb->s_security);
> -	sb->s_security = NULL;
> -}
> -
>  struct smack_mnt_opts {
>  	const char *fsdefault, *fsfloor, *fshat, *fsroot, *fstransmute;
>  };
> @@ -781,7 +764,7 @@ static int smack_set_mnt_opts(struct super_block *sb,
>  {
>  	struct dentry *root = sb->s_root;
>  	struct inode *inode = d_backing_inode(root);
> -	struct superblock_smack *sp = sb->s_security;
> +	struct superblock_smack *sp = smack_superblock(sb);
>  	struct inode_smack *isp;
>  	struct smack_known *skp;
>  	struct smack_mnt_opts *opts = mnt_opts;
> @@ -880,7 +863,7 @@ static int smack_set_mnt_opts(struct super_block *sb,
>   */
>  static int smack_sb_statfs(struct dentry *dentry)
>  {
> -	struct superblock_smack *sbp = dentry->d_sb->s_security;
> +	struct superblock_smack *sbp = smack_superblock(dentry->d_sb);
>  	int rc;
>  	struct smk_audit_info ad;
>  
> @@ -917,7 +900,7 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm)
>  	if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
>  		return 0;
>  
> -	sbsp = inode->i_sb->s_security;
> +	sbsp = smack_superblock(inode->i_sb);
>  	if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) &&
>  	    isp->smk_task != sbsp->smk_root)
>  		return 0;
> @@ -1168,7 +1151,7 @@ static int smack_inode_rename(struct inode *old_inode,
>   */
>  static int smack_inode_permission(struct inode *inode, int mask)
>  {
> -	struct superblock_smack *sbsp = inode->i_sb->s_security;
> +	struct superblock_smack *sbsp = smack_superblock(inode->i_sb);
>  	struct smk_audit_info ad;
>  	int no_block = mask & MAY_NOT_BLOCK;
>  	int rc;
> @@ -1410,7 +1393,7 @@ static int smack_inode_removexattr(struct dentry *dentry, const char *name)
>  	 */
>  	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
>  		struct super_block *sbp = dentry->d_sb;
> -		struct superblock_smack *sbsp = sbp->s_security;
> +		struct superblock_smack *sbsp = smack_superblock(sbp);
>  
>  		isp->smk_inode = sbsp->smk_default;
>  	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0)
> @@ -1680,7 +1663,7 @@ static int smack_mmap_file(struct file *file,
>  	isp = smack_inode(file_inode(file));
>  	if (isp->smk_mmap == NULL)
>  		return 0;
> -	sbsp = file_inode(file)->i_sb->s_security;
> +	sbsp = smack_superblock(file_inode(file)->i_sb);
>  	if (sbsp->smk_flags & SMK_SB_UNTRUSTED &&
>  	    isp->smk_mmap != sbsp->smk_root)
>  		return -EACCES;
> @@ -3288,7 +3271,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
>  		goto unlockandout;
>  
>  	sbp = inode->i_sb;
> -	sbsp = sbp->s_security;
> +	sbsp = smack_superblock(sbp);
>  	/*
>  	 * We're going to use the superblock default label
>  	 * if there's no label on the file.
> @@ -4575,6 +4558,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
>  	.lbs_inode = sizeof(struct inode_smack),
>  	.lbs_ipc = sizeof(struct smack_known *),
>  	.lbs_msg_msg = sizeof(struct smack_known *),
> +	.lbs_superblock = sizeof(struct superblock_smack),
>  };
>  
>  static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
> @@ -4586,7 +4570,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
>  	LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param),
>  
>  	LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
> -	LSM_HOOK_INIT(sb_free_security, smack_sb_free_security),
>  	LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
>  	LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
>  	LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 02/24] LSM: Infrastructure management of the sock security
  2019-06-21 18:52 ` [PATCH v3 02/24] LSM: Infrastructure management of the sock security Casey Schaufler
@ 2019-06-24 18:33   ` John Johansen
  0 siblings, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:33 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Move management of the sock->sk_security blob out
> of the individual security modules and into the security
> infrastructure. Instead of allocating the blobs from within
> the modules the modules tell the infrastructure how much
> space is required, and the space is allocated there.
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

a couple small things below
Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  include/linux/lsm_hooks.h         |  1 +
>  security/apparmor/include/net.h   |  6 ++-
>  security/apparmor/lsm.c           | 38 ++++-----------
>  security/security.c               | 36 +++++++++++++-
>  security/selinux/hooks.c          | 78 +++++++++++++++----------------
>  security/selinux/include/objsec.h |  5 ++
>  security/selinux/netlabel.c       | 23 ++++-----
>  security/smack/smack.h            |  5 ++
>  security/smack/smack_lsm.c        | 64 ++++++++++++-------------
>  security/smack/smack_netfilter.c  |  8 ++--
>  10 files changed, 144 insertions(+), 120 deletions(-)
> 
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index f9222a04968d..b353482ea348 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -2047,6 +2047,7 @@ struct lsm_blob_sizes {
>  	int	lbs_cred;
>  	int	lbs_file;
>  	int	lbs_inode;
> +	int	lbs_sock;
>  	int	lbs_superblock;
>  	int	lbs_ipc;
>  	int	lbs_msg_msg;
> diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h
> index 7334ac966d01..adac04e3b3cc 100644
> --- a/security/apparmor/include/net.h
> +++ b/security/apparmor/include/net.h
> @@ -55,7 +55,11 @@ struct aa_sk_ctx {
>  	struct aa_label *peer;
>  };
>  
> -#define SK_CTX(X) ((X)->sk_security)
> +static inline struct aa_sk_ctx *aa_sock(const struct sock *sk)
> +{
> +	return sk->sk_security + apparmor_blob_sizes.lbs_sock;
> +}
> +
>  #define SOCK_ctx(X) SOCK_INODE(X)->i_security
>  #define DEFINE_AUDIT_NET(NAME, OP, SK, F, T, P)				  \
>  	struct lsm_network_audit NAME ## _net = { .sk = (SK),		  \
> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
> index 49d664ddff44..2716e7731279 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -757,33 +757,15 @@ static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo
>  	return error;
>  }
>  
> -/**
> - * apparmor_sk_alloc_security - allocate and attach the sk_security field
> - */
> -static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
> -{
> -	struct aa_sk_ctx *ctx;
> -
> -	ctx = kzalloc(sizeof(*ctx), flags);
> -	if (!ctx)
> -		return -ENOMEM;
> -
> -	SK_CTX(sk) = ctx;
> -
> -	return 0;
> -}
> -
>  /**
>   * apparmor_sk_free_security - free the sk_security field
>   */
>  static void apparmor_sk_free_security(struct sock *sk)
>  {
> -	struct aa_sk_ctx *ctx = SK_CTX(sk);
> +	struct aa_sk_ctx *ctx = aa_sock(sk);
>  
> -	SK_CTX(sk) = NULL;
>  	aa_put_label(ctx->label);
>  	aa_put_label(ctx->peer);
> -	kfree(ctx);
>  }
>  
>  /**
> @@ -792,8 +774,8 @@ static void apparmor_sk_free_security(struct sock *sk)
>  static void apparmor_sk_clone_security(const struct sock *sk,
>  				       struct sock *newsk)
>  {
> -	struct aa_sk_ctx *ctx = SK_CTX(sk);
> -	struct aa_sk_ctx *new = SK_CTX(newsk);
> +	struct aa_sk_ctx *ctx = aa_sock(sk);
> +	struct aa_sk_ctx *new = aa_sock(newsk);
>  
>  	new->label = aa_get_label(ctx->label);
>  	new->peer = aa_get_label(ctx->peer);
> @@ -844,7 +826,7 @@ static int apparmor_socket_post_create(struct socket *sock, int family,
>  		label = aa_get_current_label();
>  
>  	if (sock->sk) {
> -		struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
> +		struct aa_sk_ctx *ctx = aa_sock(sock->sk);
>  
>  		aa_put_label(ctx->label);
>  		ctx->label = aa_get_label(label);
> @@ -1029,7 +1011,7 @@ static int apparmor_socket_shutdown(struct socket *sock, int how)
>   */
>  static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
>  {
> -	struct aa_sk_ctx *ctx = SK_CTX(sk);
> +	struct aa_sk_ctx *ctx = aa_sock(sk);
>  
>  	if (!skb->secmark)
>  		return 0;
> @@ -1042,7 +1024,7 @@ static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
>  
>  static struct aa_label *sk_peer_label(struct sock *sk)
>  {
> -	struct aa_sk_ctx *ctx = SK_CTX(sk);
> +	struct aa_sk_ctx *ctx = aa_sock(sk);
>  
>  	if (ctx->peer)
>  		return ctx->peer;
> @@ -1126,7 +1108,7 @@ static int apparmor_socket_getpeersec_dgram(struct socket *sock,
>   */
>  static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
>  {
> -	struct aa_sk_ctx *ctx = SK_CTX(sk);
> +	struct aa_sk_ctx *ctx = aa_sock(sk);
>  
>  	if (!ctx->label)
>  		ctx->label = aa_get_current_label();
> @@ -1136,7 +1118,7 @@ static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
>  static int apparmor_inet_conn_request(struct sock *sk, struct sk_buff *skb,
>  				      struct request_sock *req)
>  {
> -	struct aa_sk_ctx *ctx = SK_CTX(sk);
> +	struct aa_sk_ctx *ctx = aa_sock(sk);
>  
>  	if (!skb->secmark)
>  		return 0;
> @@ -1153,6 +1135,7 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
>  	.lbs_cred = sizeof(struct aa_task_ctx *),
>  	.lbs_file = sizeof(struct aa_file_ctx),
>  	.lbs_task = sizeof(struct aa_task_ctx),
> +	.lbs_sock = sizeof(struct aa_sk_ctx),
>  };
>  
>  static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
> @@ -1189,7 +1172,6 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
>  	LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
>  	LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
>  
> -	LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security),
>  	LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
>  	LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),
>  
> @@ -1581,7 +1563,7 @@ static unsigned int apparmor_ip_postroute(void *priv,
>  	if (sk == NULL)
>  		return NF_ACCEPT;
>  
> -	ctx = SK_CTX(sk);
> +	ctx = aa_sock(sk);
>  	if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
>  				    skb->secmark, sk))
>  		return NF_ACCEPT;
> diff --git a/security/security.c b/security/security.c
> index 550988a0f024..e32b7180282e 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -32,6 +32,7 @@
>  #include <linux/string.h>
>  #include <linux/msg.h>
>  #include <net/flow.h>
> +#include <net/sock.h>
>  
>  #define MAX_LSM_EVM_XATTR	2
>  
> @@ -172,6 +173,7 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed)
>  	lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode);
>  	lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc);
>  	lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg);
> +	lsm_set_blob_size(&needed->lbs_sock, &blob_sizes.lbs_sock);
>  	lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock);
>  	lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task);
>  }
> @@ -306,6 +308,7 @@ static void __init ordered_lsm_init(void)
>  	init_debug("inode blob size      = %d\n", blob_sizes.lbs_inode);
>  	init_debug("ipc blob size        = %d\n", blob_sizes.lbs_ipc);
>  	init_debug("msg_msg blob size    = %d\n", blob_sizes.lbs_msg_msg);
> +	init_debug("sock blob size       = %d\n", blob_sizes.lbs_sock);
>  	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
>  	init_debug("task blob size       = %d\n", blob_sizes.lbs_task);
>  
> @@ -605,6 +608,28 @@ static void __init lsm_early_task(struct task_struct *task)
>  		panic("%s: Early task alloc failed.\n", __func__);
>  }
>  
> +/**
> + * lsm_sock_alloc - allocate a composite sock blob
> + * @sock: the sock that needs a blob
> + * @priority: allocation mode
> + *
> + * Allocate the sock blob for all the modules
> + *
> + * Returns 0, or -ENOMEM if memory can't be allocated.
> + */
> +int lsm_sock_alloc(struct sock *sock, gfp_t priority)

should be static


> +{
> +	if (blob_sizes.lbs_sock == 0) {
> +		sock->sk_security = NULL;
> +		return 0;
> +	}
> +
> +	sock->sk_security = kzalloc(blob_sizes.lbs_sock, priority);
> +	if (sock->sk_security == NULL)
> +		return -ENOMEM;
> +	return 0;
> +}
> +
>  /**
>   * lsm_superblock_alloc - allocate a composite superblock blob
>   * @sb: the superblock that needs a blob
> @@ -2048,12 +2073,21 @@ EXPORT_SYMBOL(security_socket_getpeersec_dgram);
>  
>  int security_sk_alloc(struct sock *sk, int family, gfp_t priority)
>  {
> -	return call_int_hook(sk_alloc_security, 0, sk, family, priority);
> +	int rc = lsm_sock_alloc(sk, priority);
> +
> +	if (unlikely(rc))
> +		return rc;
> +	rc = call_int_hook(sk_alloc_security, 0, sk, family, priority);
> +	if (unlikely(rc))
> +		security_sk_free(sk);
> +	return rc;
>  }
>  
>  void security_sk_free(struct sock *sk)
>  {
>  	call_void_hook(sk_free_security, sk);
> +	kfree(sk->sk_security);
> +	sk->sk_security = NULL;
>  }
>  
>  void security_sk_clone(const struct sock *sk, struct sock *newsk)
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 7478d8eda00a..f38a6f484613 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -4319,7 +4319,7 @@ static int socket_sockcreate_sid(const struct task_security_struct *tsec,
>  
>  static int sock_has_perm(struct sock *sk, u32 perms)
>  {
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  	struct common_audit_data ad;
>  	struct lsm_network_audit net = {0,};
>  
> @@ -4376,7 +4376,7 @@ static int selinux_socket_post_create(struct socket *sock, int family,
>  	isec->initialized = LABEL_INITIALIZED;
>  
>  	if (sock->sk) {
> -		sksec = sock->sk->sk_security;
> +		sksec = selinux_sock(sock->sk);
>  		sksec->sclass = sclass;
>  		sksec->sid = sid;
>  		/* Allows detection of the first association on this socket */
> @@ -4392,8 +4392,8 @@ static int selinux_socket_post_create(struct socket *sock, int family,
>  static int selinux_socket_socketpair(struct socket *socka,
>  				     struct socket *sockb)
>  {
> -	struct sk_security_struct *sksec_a = socka->sk->sk_security;
> -	struct sk_security_struct *sksec_b = sockb->sk->sk_security;
> +	struct sk_security_struct *sksec_a = selinux_sock(socka->sk);
> +	struct sk_security_struct *sksec_b = selinux_sock(sockb->sk);
>  
>  	sksec_a->peer_sid = sksec_b->sid;
>  	sksec_b->peer_sid = sksec_a->sid;
> @@ -4408,7 +4408,7 @@ static int selinux_socket_socketpair(struct socket *socka,
>  static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
>  {
>  	struct sock *sk = sock->sk;
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  	u16 family;
>  	int err;
>  
> @@ -4540,7 +4540,7 @@ static int selinux_socket_connect_helper(struct socket *sock,
>  					 struct sockaddr *address, int addrlen)
>  {
>  	struct sock *sk = sock->sk;
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  	int err;
>  
>  	err = sock_has_perm(sk, SOCKET__CONNECT);
> @@ -4711,9 +4711,9 @@ static int selinux_socket_unix_stream_connect(struct sock *sock,
>  					      struct sock *other,
>  					      struct sock *newsk)
>  {
> -	struct sk_security_struct *sksec_sock = sock->sk_security;
> -	struct sk_security_struct *sksec_other = other->sk_security;
> -	struct sk_security_struct *sksec_new = newsk->sk_security;
> +	struct sk_security_struct *sksec_sock = selinux_sock(sock);
> +	struct sk_security_struct *sksec_other = selinux_sock(other);
> +	struct sk_security_struct *sksec_new = selinux_sock(newsk);
>  	struct common_audit_data ad;
>  	struct lsm_network_audit net = {0,};
>  	int err;
> @@ -4745,8 +4745,8 @@ static int selinux_socket_unix_stream_connect(struct sock *sock,
>  static int selinux_socket_unix_may_send(struct socket *sock,
>  					struct socket *other)
>  {
> -	struct sk_security_struct *ssec = sock->sk->sk_security;
> -	struct sk_security_struct *osec = other->sk->sk_security;
> +	struct sk_security_struct *ssec = selinux_sock(sock->sk);
> +	struct sk_security_struct *osec = selinux_sock(other->sk);
>  	struct common_audit_data ad;
>  	struct lsm_network_audit net = {0,};
>  
> @@ -4788,7 +4788,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
>  				       u16 family)
>  {
>  	int err = 0;
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  	u32 sk_sid = sksec->sid;
>  	struct common_audit_data ad;
>  	struct lsm_network_audit net = {0,};
> @@ -4821,7 +4821,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
>  static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
>  {
>  	int err;
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  	u16 family = sk->sk_family;
>  	u32 sk_sid = sksec->sid;
>  	struct common_audit_data ad;
> @@ -4889,13 +4889,15 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
>  	return err;
>  }
>  
> -static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
> -					    int __user *optlen, unsigned len)
> +static int selinux_socket_getpeersec_stream(struct socket *sock,
> +					    __user char *optval,
> +					    __user int *optlen,
> +					    unsigned int len)

any particular reason for changing the order from char __user to __user char


>  {
>  	int err = 0;
>  	char *scontext;
>  	u32 scontext_len;
> -	struct sk_security_struct *sksec = sock->sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sock->sk);
>  	u32 peer_sid = SECSID_NULL;
>  
>  	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
> @@ -4955,34 +4957,27 @@ static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *
>  
>  static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
>  {
> -	struct sk_security_struct *sksec;
> -
> -	sksec = kzalloc(sizeof(*sksec), priority);
> -	if (!sksec)
> -		return -ENOMEM;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  
>  	sksec->peer_sid = SECINITSID_UNLABELED;
>  	sksec->sid = SECINITSID_UNLABELED;
>  	sksec->sclass = SECCLASS_SOCKET;
>  	selinux_netlbl_sk_security_reset(sksec);
> -	sk->sk_security = sksec;
>  
>  	return 0;
>  }
>  
>  static void selinux_sk_free_security(struct sock *sk)
>  {
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  
> -	sk->sk_security = NULL;
>  	selinux_netlbl_sk_security_free(sksec);
> -	kfree(sksec);
>  }
>  
>  static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
>  {
> -	struct sk_security_struct *sksec = sk->sk_security;
> -	struct sk_security_struct *newsksec = newsk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
> +	struct sk_security_struct *newsksec = selinux_sock(newsk);
>  
>  	newsksec->sid = sksec->sid;
>  	newsksec->peer_sid = sksec->peer_sid;
> @@ -4996,7 +4991,7 @@ static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
>  	if (!sk)
>  		*secid = SECINITSID_ANY_SOCKET;
>  	else {
> -		struct sk_security_struct *sksec = sk->sk_security;
> +		struct sk_security_struct *sksec = selinux_sock(sk);
>  
>  		*secid = sksec->sid;
>  	}
> @@ -5006,7 +5001,7 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
>  {
>  	struct inode_security_struct *isec =
>  		inode_security_novalidate(SOCK_INODE(parent));
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  
>  	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
>  	    sk->sk_family == PF_UNIX)
> @@ -5021,7 +5016,7 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
>  static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
>  				      struct sk_buff *skb)
>  {
> -	struct sk_security_struct *sksec = ep->base.sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(ep->base.sk);
>  	struct common_audit_data ad;
>  	struct lsm_network_audit net = {0,};
>  	u8 peerlbl_active;
> @@ -5172,8 +5167,8 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname,
>  static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
>  				  struct sock *newsk)
>  {
> -	struct sk_security_struct *sksec = sk->sk_security;
> -	struct sk_security_struct *newsksec = newsk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
> +	struct sk_security_struct *newsksec = selinux_sock(newsk);
>  
>  	/* If policy does not support SECCLASS_SCTP_SOCKET then call
>  	 * the non-sctp clone version.
> @@ -5190,7 +5185,7 @@ static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
>  static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
>  				     struct request_sock *req)
>  {
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  	int err;
>  	u16 family = req->rsk_ops->family;
>  	u32 connsid;
> @@ -5211,7 +5206,7 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
>  static void selinux_inet_csk_clone(struct sock *newsk,
>  				   const struct request_sock *req)
>  {
> -	struct sk_security_struct *newsksec = newsk->sk_security;
> +	struct sk_security_struct *newsksec = selinux_sock(newsk);
>  
>  	newsksec->sid = req->secid;
>  	newsksec->peer_sid = req->peer_secid;
> @@ -5228,7 +5223,7 @@ static void selinux_inet_csk_clone(struct sock *newsk,
>  static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
>  {
>  	u16 family = sk->sk_family;
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  
>  	/* handle mapped IPv4 packets arriving via IPv6 sockets */
>  	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
> @@ -5312,7 +5307,7 @@ static int selinux_tun_dev_attach_queue(void *security)
>  static int selinux_tun_dev_attach(struct sock *sk, void *security)
>  {
>  	struct tun_security_struct *tunsec = security;
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  
>  	/* we don't currently perform any NetLabel based labeling here and it
>  	 * isn't clear that we would want to do so anyway; while we could apply
> @@ -5353,7 +5348,7 @@ static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
>  	int err = 0;
>  	u32 perm;
>  	struct nlmsghdr *nlh;
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  
>  	if (skb->len < NLMSG_HDRLEN) {
>  		err = -EINVAL;
> @@ -5494,7 +5489,7 @@ static unsigned int selinux_ip_output(struct sk_buff *skb,
>  			return NF_ACCEPT;
>  
>  		/* standard practice, label using the parent socket */
> -		sksec = sk->sk_security;
> +		sksec = selinux_sock(sk);
>  		sid = sksec->sid;
>  	} else
>  		sid = SECINITSID_KERNEL;
> @@ -5533,7 +5528,7 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
>  
>  	if (sk == NULL)
>  		return NF_ACCEPT;
> -	sksec = sk->sk_security;
> +	sksec = selinux_sock(sk);
>  
>  	ad.type = LSM_AUDIT_DATA_NET;
>  	ad.u.net = &net;
> @@ -5625,7 +5620,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb,
>  		u32 skb_sid;
>  		struct sk_security_struct *sksec;
>  
> -		sksec = sk->sk_security;
> +		sksec = selinux_sock(sk);
>  		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
>  			return NF_DROP;
>  		/* At this point, if the returned skb peerlbl is SECSID_NULL
> @@ -5654,7 +5649,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb,
>  	} else {
>  		/* Locally generated packet, fetch the security label from the
>  		 * associated socket. */
> -		struct sk_security_struct *sksec = sk->sk_security;
> +		struct sk_security_struct *sksec = selinux_sock(sk);
>  		peer_sid = sksec->sid;
>  		secmark_perm = PACKET__SEND;
>  	}
> @@ -6633,6 +6628,7 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
>  	.lbs_inode = sizeof(struct inode_security_struct),
>  	.lbs_ipc = sizeof(struct ipc_security_struct),
>  	.lbs_msg_msg = sizeof(struct msg_security_struct),
> +	.lbs_sock = sizeof(struct sk_security_struct),
>  	.lbs_superblock = sizeof(struct superblock_security_struct),
>  };
>  
> diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
> index d08d7e5d2f93..29f02b8f8f31 100644
> --- a/security/selinux/include/objsec.h
> +++ b/security/selinux/include/objsec.h
> @@ -194,4 +194,9 @@ static inline struct superblock_security_struct *selinux_superblock(
>  	return superblock->s_security + selinux_blob_sizes.lbs_superblock;
>  }
>  
> +static inline struct sk_security_struct *selinux_sock(const struct sock *sock)
> +{
> +	return sock->sk_security + selinux_blob_sizes.lbs_sock;
> +}
> +
>  #endif /* _SELINUX_OBJSEC_H_ */
> diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
> index 186e727b737b..c40914a157b7 100644
> --- a/security/selinux/netlabel.c
> +++ b/security/selinux/netlabel.c
> @@ -31,6 +31,7 @@
>  #include <linux/gfp.h>
>  #include <linux/ip.h>
>  #include <linux/ipv6.h>
> +#include <linux/lsm_hooks.h>
>  #include <net/sock.h>
>  #include <net/netlabel.h>
>  #include <net/ip.h>
> @@ -81,7 +82,7 @@ static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
>  static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
>  {
>  	int rc;
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  	struct netlbl_lsm_secattr *secattr;
>  
>  	if (sksec->nlbl_secattr != NULL)
> @@ -114,7 +115,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
>  							const struct sock *sk,
>  							u32 sid)
>  {
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  	struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr;
>  
>  	if (secattr == NULL)
> @@ -249,7 +250,7 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
>  	 * being labeled by it's parent socket, if it is just exit */
>  	sk = skb_to_full_sk(skb);
>  	if (sk != NULL) {
> -		struct sk_security_struct *sksec = sk->sk_security;
> +		struct sk_security_struct *sksec = selinux_sock(sk);
>  
>  		if (sksec->nlbl_state != NLBL_REQSKB)
>  			return 0;
> @@ -287,7 +288,7 @@ int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
>  {
>  	int rc;
>  	struct netlbl_lsm_secattr secattr;
> -	struct sk_security_struct *sksec = ep->base.sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(ep->base.sk);
>  	struct sockaddr *addr;
>  	struct sockaddr_in addr4;
>  #if IS_ENABLED(CONFIG_IPV6)
> @@ -370,7 +371,7 @@ int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
>   */
>  void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
>  {
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  
>  	if (family == PF_INET)
>  		sksec->nlbl_state = NLBL_LABELED;
> @@ -388,8 +389,8 @@ void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
>   */
>  void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
>  {
> -	struct sk_security_struct *sksec = sk->sk_security;
> -	struct sk_security_struct *newsksec = newsk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
> +	struct sk_security_struct *newsksec = selinux_sock(newsk);
>  
>  	newsksec->nlbl_state = sksec->nlbl_state;
>  }
> @@ -407,7 +408,7 @@ void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
>  int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
>  {
>  	int rc;
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  	struct netlbl_lsm_secattr *secattr;
>  
>  	if (family != PF_INET && family != PF_INET6)
> @@ -522,7 +523,7 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
>  {
>  	int rc = 0;
>  	struct sock *sk = sock->sk;
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  	struct netlbl_lsm_secattr secattr;
>  
>  	if (selinux_netlbl_option(level, optname) &&
> @@ -560,7 +561,7 @@ static int selinux_netlbl_socket_connect_helper(struct sock *sk,
>  						struct sockaddr *addr)
>  {
>  	int rc;
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  	struct netlbl_lsm_secattr *secattr;
>  
>  	/* connected sockets are allowed to disconnect when the address family
> @@ -599,7 +600,7 @@ static int selinux_netlbl_socket_connect_helper(struct sock *sk,
>  int selinux_netlbl_socket_connect_locked(struct sock *sk,
>  					 struct sockaddr *addr)
>  {
> -	struct sk_security_struct *sksec = sk->sk_security;
> +	struct sk_security_struct *sksec = selinux_sock(sk);
>  
>  	if (sksec->nlbl_state != NLBL_REQSKB &&
>  	    sksec->nlbl_state != NLBL_CONNLABELED)
> diff --git a/security/smack/smack.h b/security/smack/smack.h
> index caecbcba9942..4ac4bf3310d7 100644
> --- a/security/smack/smack.h
> +++ b/security/smack/smack.h
> @@ -375,6 +375,11 @@ static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc)
>  	return ipc->security + smack_blob_sizes.lbs_ipc;
>  }
>  
> +static inline struct socket_smack *smack_sock(const struct sock *sock)
> +{
> +	return sock->sk_security + smack_blob_sizes.lbs_sock;
> +}
> +
>  static inline struct superblock_smack *smack_superblock(
>  					const struct super_block *superblock)
>  {
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 807eff2ccce9..fd69e1bd841b 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -1439,7 +1439,7 @@ static int smack_inode_getsecurity(struct inode *inode,
>  		if (sock == NULL || sock->sk == NULL)
>  			return -EOPNOTSUPP;
>  
> -		ssp = sock->sk->sk_security;
> +		ssp = smack_sock(sock->sk);
>  
>  		if (strcmp(name, XATTR_SMACK_IPIN) == 0)
>  			isp = ssp->smk_in;
> @@ -1821,7 +1821,7 @@ static int smack_file_receive(struct file *file)
>  
>  	if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
>  		sock = SOCKET_I(inode);
> -		ssp = sock->sk->sk_security;
> +		ssp = smack_sock(sock->sk);
>  		tsp = smack_cred(current_cred());
>  		/*
>  		 * If the receiving process can't write to the
> @@ -2231,11 +2231,7 @@ static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
>  static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
>  {
>  	struct smack_known *skp = smk_of_current();
> -	struct socket_smack *ssp;
> -
> -	ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
> -	if (ssp == NULL)
> -		return -ENOMEM;
> +	struct socket_smack *ssp = smack_sock(sk);
>  
>  	/*
>  	 * Sockets created by kernel threads receive web label.
> @@ -2249,11 +2245,10 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
>  	}
>  	ssp->smk_packet = NULL;
>  
> -	sk->sk_security = ssp;
> -
>  	return 0;
>  }
>  
> +#ifdef SMACK_IPV6_PORT_LABELING
>  /**
>   * smack_sk_free_security - Free a socket blob
>   * @sk: the socket
> @@ -2262,7 +2257,6 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
>   */
>  static void smack_sk_free_security(struct sock *sk)
>  {
> -#ifdef SMACK_IPV6_PORT_LABELING
>  	struct smk_port_label *spp;
>  
>  	if (sk->sk_family == PF_INET6) {
> @@ -2275,9 +2269,8 @@ static void smack_sk_free_security(struct sock *sk)
>  		}
>  		rcu_read_unlock();
>  	}
> -#endif
> -	kfree(sk->sk_security);
>  }
> +#endif
>  
>  /**
>  * smack_ipv4host_label - check host based restrictions
> @@ -2395,7 +2388,7 @@ static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
>  static int smack_netlabel(struct sock *sk, int labeled)
>  {
>  	struct smack_known *skp;
> -	struct socket_smack *ssp = sk->sk_security;
> +	struct socket_smack *ssp = smack_sock(sk);
>  	int rc = 0;
>  
>  	/*
> @@ -2440,7 +2433,7 @@ static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
>  	int rc;
>  	int sk_lbl;
>  	struct smack_known *hkp;
> -	struct socket_smack *ssp = sk->sk_security;
> +	struct socket_smack *ssp = smack_sock(sk);
>  	struct smk_audit_info ad;
>  
>  	rcu_read_lock();
> @@ -2516,7 +2509,7 @@ static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
>  {
>  	struct sock *sk = sock->sk;
>  	struct sockaddr_in6 *addr6;
> -	struct socket_smack *ssp = sock->sk->sk_security;
> +	struct socket_smack *ssp = smack_sock(sock->sk);
>  	struct smk_port_label *spp;
>  	unsigned short port = 0;
>  
> @@ -2603,7 +2596,7 @@ static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
>  				int act)
>  {
>  	struct smk_port_label *spp;
> -	struct socket_smack *ssp = sk->sk_security;
> +	struct socket_smack *ssp = smack_sock(sk);
>  	struct smack_known *skp = NULL;
>  	unsigned short port;
>  	struct smack_known *object;
> @@ -2697,7 +2690,7 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
>  	if (sock == NULL || sock->sk == NULL)
>  		return -EOPNOTSUPP;
>  
> -	ssp = sock->sk->sk_security;
> +	ssp = smack_sock(sock->sk);
>  
>  	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
>  		ssp->smk_in = skp;
> @@ -2745,7 +2738,7 @@ static int smack_socket_post_create(struct socket *sock, int family,
>  	 * Sockets created by kernel threads receive web label.
>  	 */
>  	if (unlikely(current->flags & PF_KTHREAD)) {
> -		ssp = sock->sk->sk_security;
> +		ssp = smack_sock(sock->sk);
>  		ssp->smk_in = &smack_known_web;
>  		ssp->smk_out = &smack_known_web;
>  	}
> @@ -2770,8 +2763,8 @@ static int smack_socket_post_create(struct socket *sock, int family,
>  static int smack_socket_socketpair(struct socket *socka,
>  		                   struct socket *sockb)
>  {
> -	struct socket_smack *asp = socka->sk->sk_security;
> -	struct socket_smack *bsp = sockb->sk->sk_security;
> +	struct socket_smack *asp = smack_sock(socka->sk);
> +	struct socket_smack *bsp = smack_sock(sockb->sk);
>  
>  	asp->smk_packet = bsp->smk_out;
>  	bsp->smk_packet = asp->smk_out;
> @@ -2825,7 +2818,7 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
>  		return 0;
>  
>  #ifdef SMACK_IPV6_SECMARK_LABELING
> -	ssp = sock->sk->sk_security;
> +	ssp = smack_sock(sock->sk);
>  #endif
>  
>  	switch (sock->sk->sk_family) {
> @@ -3566,9 +3559,9 @@ static int smack_unix_stream_connect(struct sock *sock,
>  {
>  	struct smack_known *skp;
>  	struct smack_known *okp;
> -	struct socket_smack *ssp = sock->sk_security;
> -	struct socket_smack *osp = other->sk_security;
> -	struct socket_smack *nsp = newsk->sk_security;
> +	struct socket_smack *ssp = smack_sock(sock);
> +	struct socket_smack *osp = smack_sock(other);
> +	struct socket_smack *nsp = smack_sock(newsk);
>  	struct smk_audit_info ad;
>  	int rc = 0;
>  #ifdef CONFIG_AUDIT
> @@ -3614,8 +3607,8 @@ static int smack_unix_stream_connect(struct sock *sock,
>   */
>  static int smack_unix_may_send(struct socket *sock, struct socket *other)
>  {
> -	struct socket_smack *ssp = sock->sk->sk_security;
> -	struct socket_smack *osp = other->sk->sk_security;
> +	struct socket_smack *ssp = smack_sock(sock->sk);
> +	struct socket_smack *osp = smack_sock(other->sk);
>  	struct smk_audit_info ad;
>  	int rc;
>  
> @@ -3652,7 +3645,7 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
>  	struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
>  #endif
>  #ifdef SMACK_IPV6_SECMARK_LABELING
> -	struct socket_smack *ssp = sock->sk->sk_security;
> +	struct socket_smack *ssp = smack_sock(sock->sk);
>  	struct smack_known *rsp;
>  #endif
>  	int rc = 0;
> @@ -3817,7 +3810,7 @@ static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
>  static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
>  {
>  	struct netlbl_lsm_secattr secattr;
> -	struct socket_smack *ssp = sk->sk_security;
> +	struct socket_smack *ssp = smack_sock(sk);
>  	struct smack_known *skp = NULL;
>  	int rc = 0;
>  	struct smk_audit_info ad;
> @@ -3934,7 +3927,7 @@ static int smack_socket_getpeersec_stream(struct socket *sock,
>  	int slen = 1;
>  	int rc = 0;
>  
> -	ssp = sock->sk->sk_security;
> +	ssp = smack_sock(sock->sk);
>  	if (ssp->smk_packet != NULL) {
>  		rcp = ssp->smk_packet->smk_known;
>  		slen = strlen(rcp) + 1;
> @@ -3984,7 +3977,7 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
>  
>  	switch (family) {
>  	case PF_UNIX:
> -		ssp = sock->sk->sk_security;
> +		ssp = smack_sock(sock->sk);
>  		s = ssp->smk_out->smk_secid;
>  		break;
>  	case PF_INET:
> @@ -3997,7 +3990,7 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
>  		 * Translate what netlabel gave us.
>  		 */
>  		if (sock != NULL && sock->sk != NULL)
> -			ssp = sock->sk->sk_security;
> +			ssp = smack_sock(sock->sk);
>  		netlbl_secattr_init(&secattr);
>  		rc = netlbl_skbuff_getattr(skb, family, &secattr);
>  		if (rc == 0) {
> @@ -4035,7 +4028,7 @@ static void smack_sock_graft(struct sock *sk, struct socket *parent)
>  	    (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
>  		return;
>  
> -	ssp = sk->sk_security;
> +	ssp = smack_sock(sk);
>  	ssp->smk_in = skp;
>  	ssp->smk_out = skp;
>  	/* cssp->smk_packet is already set in smack_inet_csk_clone() */
> @@ -4055,7 +4048,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
>  {
>  	u16 family = sk->sk_family;
>  	struct smack_known *skp;
> -	struct socket_smack *ssp = sk->sk_security;
> +	struct socket_smack *ssp = smack_sock(sk);
>  	struct netlbl_lsm_secattr secattr;
>  	struct sockaddr_in addr;
>  	struct iphdr *hdr;
> @@ -4154,7 +4147,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
>  static void smack_inet_csk_clone(struct sock *sk,
>  				 const struct request_sock *req)
>  {
> -	struct socket_smack *ssp = sk->sk_security;
> +	struct socket_smack *ssp = smack_sock(sk);
>  	struct smack_known *skp;
>  
>  	if (req->peer_secid != 0) {
> @@ -4558,6 +4551,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
>  	.lbs_inode = sizeof(struct inode_smack),
>  	.lbs_ipc = sizeof(struct smack_known *),
>  	.lbs_msg_msg = sizeof(struct smack_known *),
> +	.lbs_sock = sizeof(struct socket_smack),
>  	.lbs_superblock = sizeof(struct superblock_smack),
>  };
>  
> @@ -4667,7 +4661,9 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
>  	LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream),
>  	LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram),
>  	LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security),
> +#ifdef SMACK_IPV6_PORT_LABELING
>  	LSM_HOOK_INIT(sk_free_security, smack_sk_free_security),
> +#endif
>  	LSM_HOOK_INIT(sock_graft, smack_sock_graft),
>  	LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request),
>  	LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone),
> diff --git a/security/smack/smack_netfilter.c b/security/smack/smack_netfilter.c
> index e36d17835d4f..701a1cc1bdcc 100644
> --- a/security/smack/smack_netfilter.c
> +++ b/security/smack/smack_netfilter.c
> @@ -31,8 +31,8 @@ static unsigned int smack_ipv6_output(void *priv,
>  	struct socket_smack *ssp;
>  	struct smack_known *skp;
>  
> -	if (sk && sk->sk_security) {
> -		ssp = sk->sk_security;
> +	if (sk && smack_sock(sk)) {
> +		ssp = smack_sock(sk);
>  		skp = ssp->smk_out;
>  		skb->secmark = skp->smk_secid;
>  	}
> @@ -49,8 +49,8 @@ static unsigned int smack_ipv4_output(void *priv,
>  	struct socket_smack *ssp;
>  	struct smack_known *skp;
>  
> -	if (sk && sk->sk_security) {
> -		ssp = sk->sk_security;
> +	if (sk && smack_sock(sk)) {
> +		ssp = smack_sock(sk);
>  		skp = ssp->smk_out;
>  		skb->secmark = skp->smk_secid;
>  	}
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 03/24] LSM: Infrastructure management of the key blob
  2019-06-21 18:52 ` [PATCH v3 03/24] LSM: Infrastructure management of the key blob Casey Schaufler
@ 2019-06-24 18:33   ` John Johansen
  0 siblings, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:33 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> From: Casey Schaufler <cschaufler@schaufler-ca.com>
> 
> Move management of the key->security blob out of the
> individual security modules and into the security
> infrastructure. Instead of allocating the blobs from within
> the modules the modules tell the infrastructure how much
> space is required, and the space is allocated there.
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

One small thing below

Reviewed-by: John Johansen <john.johansen@canonical.com>



> ---
>  include/linux/lsm_hooks.h         |  1 +
>  security/security.c               | 40 ++++++++++++++++++++++++++++++-
>  security/selinux/hooks.c          | 23 +++++-------------
>  security/selinux/include/objsec.h |  7 ++++++
>  security/smack/smack.h            |  7 ++++++
>  security/smack/smack_lsm.c        | 33 ++++++++++++-------------
>  6 files changed, 75 insertions(+), 36 deletions(-)
> 
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index b353482ea348..3fe39abccc8f 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -2050,6 +2050,7 @@ struct lsm_blob_sizes {
>  	int	lbs_sock;
>  	int	lbs_superblock;
>  	int	lbs_ipc;
> +	int	lbs_key;
>  	int	lbs_msg_msg;
>  	int	lbs_task;
>  };
> diff --git a/security/security.c b/security/security.c
> index e32b7180282e..d05f00a40e82 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -172,6 +172,9 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed)
>  		blob_sizes.lbs_inode = sizeof(struct rcu_head);
>  	lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode);
>  	lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc);
> +#ifdef CONFIG_KEYS
> +	lsm_set_blob_size(&needed->lbs_key, &blob_sizes.lbs_key);
> +#endif
>  	lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg);
>  	lsm_set_blob_size(&needed->lbs_sock, &blob_sizes.lbs_sock);
>  	lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock);
> @@ -307,6 +310,9 @@ static void __init ordered_lsm_init(void)
>  	init_debug("file blob size       = %d\n", blob_sizes.lbs_file);
>  	init_debug("inode blob size      = %d\n", blob_sizes.lbs_inode);
>  	init_debug("ipc blob size        = %d\n", blob_sizes.lbs_ipc);
> +#ifdef CONFIG_KEYS
> +	init_debug("key blob size        = %d\n", blob_sizes.lbs_key);
> +#endif /* CONFIG_KEYS */
>  	init_debug("msg_msg blob size    = %d\n", blob_sizes.lbs_msg_msg);
>  	init_debug("sock blob size       = %d\n", blob_sizes.lbs_sock);
>  	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
> @@ -573,6 +579,29 @@ static int lsm_ipc_alloc(struct kern_ipc_perm *kip)
>  	return 0;
>  }
>  
> +#ifdef CONFIG_KEYS
> +/**
> + * lsm_key_alloc - allocate a composite key blob
> + * @key: the key that needs a blob
> + *
> + * Allocate the key blob for all the modules
> + *
> + * Returns 0, or -ENOMEM if memory can't be allocated.
> + */
> +int lsm_key_alloc(struct key *key)

should be static


> +{
> +	if (blob_sizes.lbs_key == 0) {
> +		key->security = NULL;
> +		return 0;
> +	}
> +
> +	key->security = kzalloc(blob_sizes.lbs_key, GFP_KERNEL);
> +	if (key->security == NULL)
> +		return -ENOMEM;
> +	return 0;
> +}
> +#endif /* CONFIG_KEYS */
> +
>  /**
>   * lsm_msg_msg_alloc - allocate a composite msg_msg blob
>   * @mp: the msg_msg that needs a blob
> @@ -2339,12 +2368,21 @@ EXPORT_SYMBOL(security_skb_classify_flow);
>  int security_key_alloc(struct key *key, const struct cred *cred,
>  		       unsigned long flags)
>  {
> -	return call_int_hook(key_alloc, 0, key, cred, flags);
> +	int rc = lsm_key_alloc(key);
> +
> +	if (unlikely(rc))
> +		return rc;
> +	rc = call_int_hook(key_alloc, 0, key, cred, flags);
> +	if (unlikely(rc))
> +		security_key_free(key);
> +	return rc;
>  }
>  
>  void security_key_free(struct key *key)
>  {
>  	call_void_hook(key_free, key);
> +	kfree(key->security);
> +	key->security = NULL;
>  }
>  
>  int security_key_permission(key_ref_t key_ref,
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index f38a6f484613..ee840fecfebb 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -6353,11 +6353,7 @@ static int selinux_key_alloc(struct key *k, const struct cred *cred,
>  			     unsigned long flags)
>  {
>  	const struct task_security_struct *tsec;
> -	struct key_security_struct *ksec;
> -
> -	ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
> -	if (!ksec)
> -		return -ENOMEM;
> +	struct key_security_struct *ksec = selinux_key(k);
>  
>  	tsec = selinux_cred(cred);
>  	if (tsec->keycreate_sid)
> @@ -6365,18 +6361,9 @@ static int selinux_key_alloc(struct key *k, const struct cred *cred,
>  	else
>  		ksec->sid = tsec->sid;
>  
> -	k->security = ksec;
>  	return 0;
>  }
>  
> -static void selinux_key_free(struct key *k)
> -{
> -	struct key_security_struct *ksec = k->security;
> -
> -	k->security = NULL;
> -	kfree(ksec);
> -}
> -
>  static int selinux_key_permission(key_ref_t key_ref,
>  				  const struct cred *cred,
>  				  unsigned perm)
> @@ -6394,7 +6381,7 @@ static int selinux_key_permission(key_ref_t key_ref,
>  	sid = cred_sid(cred);
>  
>  	key = key_ref_to_ptr(key_ref);
> -	ksec = key->security;
> +	ksec = selinux_key(key);
>  
>  	return avc_has_perm(&selinux_state,
>  			    sid, ksec->sid, SECCLASS_KEY, perm, NULL);
> @@ -6402,7 +6389,7 @@ static int selinux_key_permission(key_ref_t key_ref,
>  
>  static int selinux_key_getsecurity(struct key *key, char **_buffer)
>  {
> -	struct key_security_struct *ksec = key->security;
> +	struct key_security_struct *ksec = selinux_key(key);
>  	char *context = NULL;
>  	unsigned len;
>  	int rc;
> @@ -6627,6 +6614,9 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
>  	.lbs_file = sizeof(struct file_security_struct),
>  	.lbs_inode = sizeof(struct inode_security_struct),
>  	.lbs_ipc = sizeof(struct ipc_security_struct),
> +#ifdef CONFIG_KEYS
> +	.lbs_key = sizeof(struct key_security_struct),
> +#endif /* CONFIG_KEYS */
>  	.lbs_msg_msg = sizeof(struct msg_security_struct),
>  	.lbs_sock = sizeof(struct sk_security_struct),
>  	.lbs_superblock = sizeof(struct superblock_security_struct),
> @@ -6842,7 +6832,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
>  
>  #ifdef CONFIG_KEYS
>  	LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
> -	LSM_HOOK_INIT(key_free, selinux_key_free),
>  	LSM_HOOK_INIT(key_permission, selinux_key_permission),
>  	LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
>  #endif
> diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
> index 29f02b8f8f31..3b78aa4ee98f 100644
> --- a/security/selinux/include/objsec.h
> +++ b/security/selinux/include/objsec.h
> @@ -194,6 +194,13 @@ static inline struct superblock_security_struct *selinux_superblock(
>  	return superblock->s_security + selinux_blob_sizes.lbs_superblock;
>  }
>  
> +#ifdef CONFIG_KEYS
> +static inline struct key_security_struct *selinux_key(const struct key *key)
> +{
> +	return key->security + selinux_blob_sizes.lbs_key;
> +}
> +#endif /* CONFIG_KEYS */
> +
>  static inline struct sk_security_struct *selinux_sock(const struct sock *sock)
>  {
>  	return sock->sk_security + selinux_blob_sizes.lbs_sock;
> diff --git a/security/smack/smack.h b/security/smack/smack.h
> index 4ac4bf3310d7..7cc3a3382fee 100644
> --- a/security/smack/smack.h
> +++ b/security/smack/smack.h
> @@ -386,6 +386,13 @@ static inline struct superblock_smack *smack_superblock(
>  	return superblock->s_security + smack_blob_sizes.lbs_superblock;
>  }
>  
> +#ifdef CONFIG_KEYS
> +static inline struct smack_known **smack_key(const struct key *key)
> +{
> +	return key->security + smack_blob_sizes.lbs_key;
> +}
> +#endif /* CONFIG_KEYS */
> +
>  /*
>   * Is the directory transmuting?
>   */
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index fd69e1bd841b..e9560b078efe 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -4179,23 +4179,13 @@ static void smack_inet_csk_clone(struct sock *sk,
>  static int smack_key_alloc(struct key *key, const struct cred *cred,
>  			   unsigned long flags)
>  {
> +	struct smack_known **blob = smack_key(key);
>  	struct smack_known *skp = smk_of_task(smack_cred(cred));
>  
> -	key->security = skp;
> +	*blob = skp;
>  	return 0;
>  }
>  
> -/**
> - * smack_key_free - Clear the key security blob
> - * @key: the object
> - *
> - * Clear the blob pointer
> - */
> -static void smack_key_free(struct key *key)
> -{
> -	key->security = NULL;
> -}
> -
>  /**
>   * smack_key_permission - Smack access on a key
>   * @key_ref: gets to the object
> @@ -4208,6 +4198,8 @@ static void smack_key_free(struct key *key)
>  static int smack_key_permission(key_ref_t key_ref,
>  				const struct cred *cred, unsigned perm)
>  {
> +	struct smack_known **blob;
> +	struct smack_known *skp;
>  	struct key *keyp;
>  	struct smk_audit_info ad;
>  	struct smack_known *tkp = smk_of_task(smack_cred(cred));
> @@ -4227,7 +4219,9 @@ static int smack_key_permission(key_ref_t key_ref,
>  	 * If the key hasn't been initialized give it access so that
>  	 * it may do so.
>  	 */
> -	if (keyp->security == NULL)
> +	blob = smack_key(keyp);
> +	skp = *blob;
> +	if (skp == NULL)
>  		return 0;
>  	/*
>  	 * This should not occur
> @@ -4247,8 +4241,8 @@ static int smack_key_permission(key_ref_t key_ref,
>  		request |= MAY_READ;
>  	if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR))
>  		request |= MAY_WRITE;
> -	rc = smk_access(tkp, keyp->security, request, &ad);
> -	rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
> +	rc = smk_access(tkp, skp, request, &ad);
> +	rc = smk_bu_note("key access", tkp, skp, request, rc);
>  	return rc;
>  }
>  
> @@ -4263,11 +4257,12 @@ static int smack_key_permission(key_ref_t key_ref,
>   */
>  static int smack_key_getsecurity(struct key *key, char **_buffer)
>  {
> -	struct smack_known *skp = key->security;
> +	struct smack_known **blob = smack_key(key);
> +	struct smack_known *skp = *blob;
>  	size_t length;
>  	char *copy;
>  
> -	if (key->security == NULL) {
> +	if (skp == NULL) {
>  		*_buffer = NULL;
>  		return 0;
>  	}
> @@ -4550,6 +4545,9 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
>  	.lbs_file = sizeof(struct smack_known *),
>  	.lbs_inode = sizeof(struct inode_smack),
>  	.lbs_ipc = sizeof(struct smack_known *),
> +#ifdef CONFIG_KEYS
> +	.lbs_key = sizeof(struct smack_known *),
> +#endif /* CONFIG_KEYS */
>  	.lbs_msg_msg = sizeof(struct smack_known *),
>  	.lbs_sock = sizeof(struct socket_smack),
>  	.lbs_superblock = sizeof(struct superblock_smack),
> @@ -4671,7 +4669,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
>   /* key management security hooks */
>  #ifdef CONFIG_KEYS
>  	LSM_HOOK_INIT(key_alloc, smack_key_alloc),
> -	LSM_HOOK_INIT(key_free, smack_key_free),
>  	LSM_HOOK_INIT(key_permission, smack_key_permission),
>  	LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity),
>  #endif /* CONFIG_KEYS */
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 04/24] LSM: Create and manage the lsmblob data structure.
  2019-06-21 18:52 ` [PATCH v3 04/24] LSM: Create and manage the lsmblob data structure Casey Schaufler
  2019-06-22 22:42   ` Kees Cook
@ 2019-06-24 18:38   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:38 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> When more than one security module is exporting data to
> audit and networking sub-systems a single 32 bit integer
> is no longer sufficient to represent the data. Add a
> structure to be used instead.
> 
> The lsmblob structure is currently an array of
> u32 "secids". There is an entry for each of the
> security modules built into the system that would
> use secids if active. The system assigns the module
> a "slot" when it registers hooks. If modules are
> compiled in but not registered there will be unused
> slots.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

See below


> ---
>  include/linux/lsm_hooks.h |  1 +
>  include/linux/security.h  | 62 +++++++++++++++++++++++++++++++++++++++
>  security/security.c       | 36 +++++++++++++++++++++++
>  3 files changed, 99 insertions(+)
> 
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index 3fe39abccc8f..4d1ddf1a2aa6 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -2038,6 +2038,7 @@ struct security_hook_list {
>  	struct hlist_head		*head;
>  	union security_list_options	hook;
>  	char				*lsm;
> +	int				slot;
>  } __randomize_layout;
>

I agree with Kees, *lsm and slot should be moved to the lsm_info
and a lsm_info * should take their place here. This will help
with slot assignment below. But this can come as a separate
patch later.



>  /*
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 49f2685324b0..0aa9417a5762 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -76,6 +76,68 @@ enum lsm_event {
>  	LSM_POLICY_CHANGE,
>  };
>  
> +/*
> + * Data exported by the security modules
> + */
> +#define LSMBLOB_ENTRIES ( \
> +	(IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \
> +	(IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \
> +	(IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0))
> +
> +struct lsmblob {
> +	u32     secid[LSMBLOB_ENTRIES];
> +};
> +
> +#define LSMBLOB_INVALID	-1
> +
> +/**
> + * lsmblob_init - initialize an lsmblob structure.
> + * @blob: Pointer to the data to initialize
> + * @secid: The initial secid value
> + *
> + * Set all secid for all modules to the specified value.
> + */
> +static inline void lsmblob_init(struct lsmblob *blob, u32 secid)
> +{
> +	int i;
> +
> +	for (i = 0; i < LSMBLOB_ENTRIES; i++)
> +		blob->secid[i] = secid;
> +}
> +
> +/**
> + * lsmblob_is_set - report if there is an value in the lsmblob
> + * @blob: Pointer to the exported LSM data
> + *
> + * Returns true if there is a secid set, false otherwise
> + */
> +static inline bool lsmblob_is_set(struct lsmblob *blob)
> +{
> +	int i;
> +
> +	for (i = 0; i < LSMBLOB_ENTRIES; i++)
> +		if (blob->secid[i] != 0)
> +			return true;
> +	return false;
> +}
> +
> +/**
> + * lsmblob_equal - report if the two lsmblob's are equal
> + * @bloba: Pointer to one LSM data
> + * @blobb: Pointer to the other LSM data
> + *
> + * Returns true if all entries in the two are equal, false otherwise
> + */
> +static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)
> +{
> +	int i;
> +
> +	for (i = 0; i < LSMBLOB_ENTRIES; i++)
> +		if (bloba->secid[i] != blobb->secid[i])
> +			return false;
> +	return true;
> +}
> +
>  /* These functions are in security/commoncap.c */
>  extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
>  		       int cap, unsigned int opts);
> diff --git a/security/security.c b/security/security.c
> index d05f00a40e82..7618c761060d 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -317,6 +317,7 @@ static void __init ordered_lsm_init(void)
>  	init_debug("sock blob size       = %d\n", blob_sizes.lbs_sock);
>  	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
>  	init_debug("task blob size       = %d\n", blob_sizes.lbs_task);
> +	init_debug("lsmblob size         = %lu\n", sizeof(struct lsmblob));
>  
>  	/*
>  	 * Create any kmem_caches needed for blobs
> @@ -420,6 +421,11 @@ static int lsm_append(char *new, char **result)
>  	return 0;
>  }
>  
> +/*
> + * Current index to use while initializing the lsmblob secid list.
> + */
> +static int lsm_slot __initdata;
> +
>  /**
>   * security_add_hooks - Add a modules hooks to the hook lists.
>   * @hooks: the hooks to add
> @@ -427,15 +433,45 @@ static int lsm_append(char *new, char **result)
>   * @lsm: the name of the security module
>   *
>   * Each LSM has to register its hooks with the infrastructure.
> + * If the LSM is using hooks that export secids allocate a slot
> + * for it in the lsmblob.
>   */
>  void __init security_add_hooks(struct security_hook_list *hooks, int count,
>  				char *lsm)
>  {
> +	int slot = LSMBLOB_INVALID;
>  	int i;
>  
>  	for (i = 0; i < count; i++) {
>  		hooks[i].lsm = lsm;
>  		hlist_add_tail_rcu(&hooks[i].list, hooks[i].head);
> +		/*
> +		 * If this is one of the hooks that uses a secid
> +		 * note it so that a slot can in allocated for the
> +		 * secid in the lsmblob structure.
> +		 */
> +		if (hooks[i].head == &security_hook_heads.audit_rule_match ||
> +		    hooks[i].head == &security_hook_heads.kernel_act_as ||
> +		    hooks[i].head ==
> +			&security_hook_heads.socket_getpeersec_dgram ||
> +		    hooks[i].head == &security_hook_heads.getprocattr ||
> +		    hooks[i].head == &security_hook_heads.setprocattr ||
> +		    hooks[i].head == &security_hook_heads.secctx_to_secid ||
> +		    hooks[i].head == &security_hook_heads.secid_to_secctx ||
> +		    hooks[i].head == &security_hook_heads.ipc_getsecid ||
> +		    hooks[i].head == &security_hook_heads.task_getsecid ||
> +		    hooks[i].head == &security_hook_heads.inode_getsecid ||
> +		    hooks[i].head == &security_hook_heads.cred_getsecid) {
> +			if (slot == LSMBLOB_INVALID) {
> +				slot = lsm_slot++;
> +				if (slot >= LSMBLOB_ENTRIES)
> +					panic("%s Too many LSMs registered.\n",
> +					      __func__);
> +				init_debug("%s assigned lsmblob slot %d\n",
> +					hooks[i].lsm, slot);
> +			}
> +		}
> +		hooks[i].slot = slot;

This is inconsistent, it sets hooks[i].slot before the first occurrence of a hook
in the above list to LSMBLOB_INVALID and the rest of the hooks[i].slots to the
assigned slot value.

If this should only be assigned to the hooks that use a secid then move the
hooks[i].slot = slot assignment into the if. Otherwise we should make sure all
hooks get assigned the same slot value.


>  	}
>  	if (lsm_append(lsm, &lsm_names) < 0)
>  		panic("%s - Cannot get early memory.\n", __func__);
> 






^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 06/24] LSM: Use lsmblob in security_kernel_act_as
  2019-06-21 18:52 ` [PATCH v3 06/24] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
  2019-06-22 22:43   ` Kees Cook
@ 2019-06-24 18:38   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:38 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change the security_kernel_act_as interface to use a lsmblob
> structure in place of the single u32 secid in support of
> module stacking. Change it's only caller, set_security_override,
> to do the same. Change that one's only caller,
> set_security_override_from_ctx, to call it with the new
> parameter type.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  include/linux/cred.h     |  3 ++-
>  include/linux/security.h |  5 +++--
>  kernel/cred.c            | 10 ++++++----
>  security/security.c      | 12 ++++++++++--
>  4 files changed, 21 insertions(+), 9 deletions(-)
> 
> diff --git a/include/linux/cred.h b/include/linux/cred.h
> index efb6edf32de7..9a21c376ed97 100644
> --- a/include/linux/cred.h
> +++ b/include/linux/cred.h
> @@ -22,6 +22,7 @@
>  
>  struct cred;
>  struct inode;
> +struct lsmblob;
>  
>  /*
>   * COW Supplementary groups list
> @@ -165,7 +166,7 @@ extern const struct cred *override_creds(const struct cred *);
>  extern void revert_creds(const struct cred *);
>  extern struct cred *prepare_kernel_cred(struct task_struct *);
>  extern int change_create_files_as(struct cred *, struct inode *);
> -extern int set_security_override(struct cred *, u32);
> +extern int set_security_override(struct cred *, struct lsmblob *);
>  extern int set_security_override_from_ctx(struct cred *, const char *);
>  extern int set_create_files_as(struct cred *, struct inode *);
>  extern int cred_fscmp(const struct cred *, const struct cred *);
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 52d89c4a9594..4a78516cc74a 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -384,7 +384,7 @@ void security_cred_free(struct cred *cred);
>  int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
>  void security_transfer_creds(struct cred *new, const struct cred *old);
>  void security_cred_getsecid(const struct cred *c, u32 *secid);
> -int security_kernel_act_as(struct cred *new, u32 secid);
> +int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
>  int security_kernel_create_files_as(struct cred *new, struct inode *inode);
>  int security_kernel_module_request(char *kmod_name);
>  int security_kernel_load_data(enum kernel_load_data_id id);
> @@ -967,7 +967,8 @@ static inline void security_transfer_creds(struct cred *new,
>  {
>  }
>  
> -static inline int security_kernel_act_as(struct cred *cred, u32 secid)
> +static inline int security_kernel_act_as(struct cred *cred,
> +					 struct lsmblob *blob)
>  {
>  	return 0;
>  }
> diff --git a/kernel/cred.c b/kernel/cred.c
> index 45d77284aed0..71c14dda107e 100644
> --- a/kernel/cred.c
> +++ b/kernel/cred.c
> @@ -701,14 +701,14 @@ EXPORT_SYMBOL(prepare_kernel_cred);
>  /**
>   * set_security_override - Set the security ID in a set of credentials
>   * @new: The credentials to alter
> - * @secid: The LSM security ID to set
> + * @blob: The LSM security information to set
>   *
>   * Set the LSM security ID in a set of credentials so that the subjective
>   * security is overridden when an alternative set of credentials is used.
>   */
> -int set_security_override(struct cred *new, u32 secid)
> +int set_security_override(struct cred *new, struct lsmblob *blob)
>  {
> -	return security_kernel_act_as(new, secid);
> +	return security_kernel_act_as(new, blob);
>  }
>  EXPORT_SYMBOL(set_security_override);
>  
> @@ -724,6 +724,7 @@ EXPORT_SYMBOL(set_security_override);
>   */
>  int set_security_override_from_ctx(struct cred *new, const char *secctx)
>  {
> +	struct lsmblob blob;
>  	u32 secid;
>  	int ret;
>  
> @@ -731,7 +732,8 @@ int set_security_override_from_ctx(struct cred *new, const char *secctx)
>  	if (ret < 0)
>  		return ret;
>  
> -	return set_security_override(new, secid);
> +	lsmblob_init(&blob, secid);
> +	return set_security_override(new, &blob);
>  }
>  EXPORT_SYMBOL(set_security_override_from_ctx);
>  
> diff --git a/security/security.c b/security/security.c
> index 4692f44718c6..43f8018b9e13 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1646,9 +1646,17 @@ void security_cred_getsecid(const struct cred *c, u32 *secid)
>  }
>  EXPORT_SYMBOL(security_cred_getsecid);
>  
> -int security_kernel_act_as(struct cred *new, u32 secid)
> +int security_kernel_act_as(struct cred *new, struct lsmblob *blob)
>  {
> -	return call_int_hook(kernel_act_as, 0, new, secid);
> +	struct security_hook_list *hp;
> +	int rc;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.kernel_act_as, list) {
> +		rc = hp->hook.kernel_act_as(new, blob->secid[hp->slot]);
> +		if (rc != 0)
> +			return rc;
> +	}
> +	return 0;
>  }
>  
>  int security_kernel_create_files_as(struct cred *new, struct inode *inode)
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 08/24] LSM: Use lsmblob in security_secctx_to_secid
  2019-06-21 18:52 ` [PATCH v3 08/24] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
  2019-06-22 22:44   ` Kees Cook
@ 2019-06-24 18:38   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:38 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change security_secctx_to_secid() to fill in a lsmblob instead
> of a u32 secid. Multiple LSMs may be able to interpret the
> string, and this allows for setting whichever secid is
> appropriate. In some cases there is scaffolding where other
> interfaces have yet to be converted.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  include/linux/security.h          |  5 +++--
>  kernel/cred.c                     |  4 +---
>  net/netfilter/nft_meta.c          | 13 ++++++-------
>  net/netfilter/xt_SECMARK.c        |  5 ++++-
>  net/netlabel/netlabel_unlabeled.c | 14 ++++++++------
>  security/security.c               | 16 +++++++++++++---
>  6 files changed, 35 insertions(+), 22 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 905830a90745..b0395d224c43 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -443,7 +443,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>  int security_netlink_send(struct sock *sk, struct sk_buff *skb);
>  int security_ismaclabel(const char *name);
>  int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
> -int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
> +int security_secctx_to_secid(const char *secdata, u32 seclen,
> +			     struct lsmblob *blob);
>  void security_release_secctx(char *secdata, u32 seclen);
>  
>  void security_inode_invalidate_secctx(struct inode *inode);
> @@ -1226,7 +1227,7 @@ static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *secle
>  
>  static inline int security_secctx_to_secid(const char *secdata,
>  					   u32 seclen,
> -					   u32 *secid)
> +					   struct lsmblob *blob)
>  {
>  	return -EOPNOTSUPP;
>  }
> diff --git a/kernel/cred.c b/kernel/cred.c
> index 71c14dda107e..d70a2c02ced4 100644
> --- a/kernel/cred.c
> +++ b/kernel/cred.c
> @@ -725,14 +725,12 @@ EXPORT_SYMBOL(set_security_override);
>  int set_security_override_from_ctx(struct cred *new, const char *secctx)
>  {
>  	struct lsmblob blob;
> -	u32 secid;
>  	int ret;
>  
> -	ret = security_secctx_to_secid(secctx, strlen(secctx), &secid);
> +	ret = security_secctx_to_secid(secctx, strlen(secctx), &blob);
>  	if (ret < 0)
>  		return ret;
>  
> -	lsmblob_init(&blob, secid);
>  	return set_security_override(new, &blob);
>  }
>  EXPORT_SYMBOL(set_security_override_from_ctx);
> diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
> index 987d2d6ce624..91973d3a5f6a 100644
> --- a/net/netfilter/nft_meta.c
> +++ b/net/netfilter/nft_meta.c
> @@ -576,21 +576,20 @@ static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = {
>  
>  static int nft_secmark_compute_secid(struct nft_secmark *priv)
>  {
> -	u32 tmp_secid = 0;
> +	struct lsmblob blob;
>  	int err;
>  
> -	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
> +	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &blob);
>  	if (err)
>  		return err;
>  
> -	if (!tmp_secid)
> -		return -ENOENT;
> -
> -	err = security_secmark_relabel_packet(tmp_secid);
> +	/* Using le[0] is scaffolding */
> +	err = security_secmark_relabel_packet(blob.secid[0]);
>  	if (err)
>  		return err;
>  
> -	priv->secid = tmp_secid;
> +	/* Using le[1] is scaffolding */
> +	priv->secid = blob.secid[0];
>  	return 0;
>  }
>  
> diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
> index f16202d26c20..8081fadc30e9 100644
> --- a/net/netfilter/xt_SECMARK.c
> +++ b/net/netfilter/xt_SECMARK.c
> @@ -49,13 +49,14 @@ secmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
>  
>  static int checkentry_lsm(struct xt_secmark_target_info *info)
>  {
> +	struct lsmblob blob;
>  	int err;
>  
>  	info->secctx[SECMARK_SECCTX_MAX - 1] = '\0';
>  	info->secid = 0;
>  
>  	err = security_secctx_to_secid(info->secctx, strlen(info->secctx),
> -				       &info->secid);
> +				       &blob);
>  	if (err) {
>  		if (err == -EINVAL)
>  			pr_info_ratelimited("invalid security context \'%s\'\n",
> @@ -63,6 +64,8 @@ static int checkentry_lsm(struct xt_secmark_target_info *info)
>  		return err;
>  	}
>  
> +	/* scaffolding during the transition */
> +	info->secid = blob.secid[0];
>  	if (!info->secid) {
>  		pr_info_ratelimited("unable to map security context \'%s\'\n",
>  				    info->secctx);
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index c92894c3e40a..2976370e41aa 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -895,7 +895,7 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
>  	void *addr;
>  	void *mask;
>  	u32 addr_len;
> -	u32 secid;
> +	struct lsmblob blob;
>  	struct netlbl_audit audit_info;
>  
>  	/* Don't allow users to add both IPv4 and IPv6 addresses for a
> @@ -919,12 +919,13 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
>  	ret_val = security_secctx_to_secid(
>  		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
>  				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
> -				  &secid);
> +				  &blob);
>  	if (ret_val != 0)
>  		return ret_val;
>  
> +	/* scaffolding with the [0] */
>  	return netlbl_unlhsh_add(&init_net,
> -				 dev_name, addr, mask, addr_len, secid,
> +				 dev_name, addr, mask, addr_len, blob.secid[0],
>  				 &audit_info);
>  }
>  
> @@ -946,7 +947,7 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
>  	void *addr;
>  	void *mask;
>  	u32 addr_len;
> -	u32 secid;
> +	struct lsmblob blob;
>  	struct netlbl_audit audit_info;
>  
>  	/* Don't allow users to add both IPv4 and IPv6 addresses for a
> @@ -968,12 +969,13 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
>  	ret_val = security_secctx_to_secid(
>  		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
>  				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
> -				  &secid);
> +				  &blob);
>  	if (ret_val != 0)
>  		return ret_val;
>  
> +	/* scaffolding with the [0] */
>  	return netlbl_unlhsh_add(&init_net,
> -				 NULL, addr, mask, addr_len, secid,
> +				 NULL, addr, mask, addr_len, blob.secid[0],
>  				 &audit_info);
>  }
>  
> diff --git a/security/security.c b/security/security.c
> index c7b3d1a294ad..cb1545bfe8c5 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1999,10 +1999,20 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
>  }
>  EXPORT_SYMBOL(security_secid_to_secctx);
>  
> -int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
> +int security_secctx_to_secid(const char *secdata, u32 seclen,
> +			     struct lsmblob *blob)
>  {
> -	*secid = 0;
> -	return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid);
> +	struct security_hook_list *hp;
> +	int rc;
> +
> +	lsmblob_init(blob, 0);
> +	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
> +		rc = hp->hook.secctx_to_secid(secdata, seclen,
> +					      &blob->secid[hp->slot]);
> +		if (rc != 0)
> +			return rc;
> +	}
> +	return 0;
>  }
>  EXPORT_SYMBOL(security_secctx_to_secid);
>  
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 05/24] Use lsmblob in security_audit_rule_match
  2019-06-21 18:52 ` [PATCH v3 05/24] Use lsmblob in security_audit_rule_match Casey Schaufler
  2019-06-22 22:43   ` Kees Cook
@ 2019-06-24 18:39   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:39 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change the secid parameter of security_audit_rule_match
> to a lsmblob structure pointer. Pass the entry from the
> lsmblob structure for the approprite slot to the LSM hook.
> 
> Change the users of security_audit_rule_match to use the
> lsmblob instead of a u32. In some cases this requires a
> temporary conversion using lsmblob_init() that will go
> away when other interfaces get converted.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  include/linux/security.h            |  7 ++++---
>  kernel/auditfilter.c                |  4 +++-
>  kernel/auditsc.c                    | 14 ++++++++++----
>  security/integrity/ima/ima.h        |  4 ++--
>  security/integrity/ima/ima_policy.c |  7 +++++--
>  security/security.c                 | 14 ++++++++++++--
>  6 files changed, 36 insertions(+), 14 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 0aa9417a5762..52d89c4a9594 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -1757,7 +1757,8 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer)
>  #ifdef CONFIG_SECURITY
>  int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule);
>  int security_audit_rule_known(struct audit_krule *krule);
> -int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule);
> +int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
> +			      void *lsmrule);
>  void security_audit_rule_free(void *lsmrule);
>  
>  #else
> @@ -1773,8 +1774,8 @@ static inline int security_audit_rule_known(struct audit_krule *krule)
>  	return 0;
>  }
>  
> -static inline int security_audit_rule_match(u32 secid, u32 field, u32 op,
> -					    void *lsmrule)
> +static inline int security_audit_rule_match(struct lsmblob *blob, u32 field,
> +					    u32 op, void *lsmrule)
>  {
>  	return 0;
>  }
> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> index 63f8b3f26fab..da211065160f 100644
> --- a/kernel/auditfilter.c
> +++ b/kernel/auditfilter.c
> @@ -1324,6 +1324,7 @@ int audit_filter(int msgtype, unsigned int listtype)
>  			struct audit_field *f = &e->rule.fields[i];
>  			pid_t pid;
>  			u32 sid;
> +			struct lsmblob blob;
>  
>  			switch (f->type) {
>  			case AUDIT_PID:
> @@ -1354,7 +1355,8 @@ int audit_filter(int msgtype, unsigned int listtype)
>  			case AUDIT_SUBJ_CLR:
>  				if (f->lsm_rule) {
>  					security_task_getsecid(current, &sid);
> -					result = security_audit_rule_match(sid,
> +					lsmblob_init(&blob, sid);
> +					result = security_audit_rule_match(&blob,
>  						   f->type, f->op, f->lsm_rule);
>  				}
>  				break;
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index d1eab1d4a930..18ee5556c086 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -445,6 +445,7 @@ static int audit_filter_rules(struct task_struct *tsk,
>  	const struct cred *cred;
>  	int i, need_sid = 1;
>  	u32 sid;
> +	struct lsmblob blob;
>  	unsigned int sessionid;
>  
>  	cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
> @@ -630,7 +631,9 @@ static int audit_filter_rules(struct task_struct *tsk,
>  					security_task_getsecid(tsk, &sid);
>  					need_sid = 0;
>  				}
> -				result = security_audit_rule_match(sid, f->type,
> +				lsmblob_init(&blob, sid);
> +				result = security_audit_rule_match(&blob,
> +								   f->type,
>  								   f->op,
>  								   f->lsm_rule);
>  			}
> @@ -645,15 +648,17 @@ static int audit_filter_rules(struct task_struct *tsk,
>  			if (f->lsm_rule) {
>  				/* Find files that match */
>  				if (name) {
> +					lsmblob_init(&blob, name->osid);
>  					result = security_audit_rule_match(
> -								name->osid,
> +								&blob,
>  								f->type,
>  								f->op,
>  								f->lsm_rule);
>  				} else if (ctx) {
>  					list_for_each_entry(n, &ctx->names_list, list) {
> +						lsmblob_init(&blob, n->osid);
>  						if (security_audit_rule_match(
> -								n->osid,
> +								&blob,
>  								f->type,
>  								f->op,
>  								f->lsm_rule)) {
> @@ -665,7 +670,8 @@ static int audit_filter_rules(struct task_struct *tsk,
>  				/* Find ipc objects that match */
>  				if (!ctx || ctx->type != AUDIT_IPC)
>  					break;
> -				if (security_audit_rule_match(ctx->ipc.osid,
> +				lsmblob_init(&blob, ctx->ipc.osid);
> +				if (security_audit_rule_match(&blob,
>  							      f->type, f->op,
>  							      f->lsm_rule))
>  					++result;
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index d213e835c498..5a337239d9e4 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -307,8 +307,8 @@ static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
>  	return -EINVAL;
>  }
>  
> -static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
> -					     void *lsmrule)
> +static inline int security_filter_rule_match(struct lsmblob *blob, u32 field,
> +					     u32 op, void *lsmrule)
>  {
>  	return -EINVAL;
>  }
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index e0cc323f948f..e7b8ce942950 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -327,6 +327,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  	for (i = 0; i < MAX_LSM_RULES; i++) {
>  		int rc = 0;
>  		u32 osid;
> +		struct lsmblob blob;
>  		int retried = 0;
>  
>  		if (!rule->lsm[i].rule)
> @@ -337,7 +338,8 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  		case LSM_OBJ_ROLE:
>  		case LSM_OBJ_TYPE:
>  			security_inode_getsecid(inode, &osid);
> -			rc = security_filter_rule_match(osid,
> +			lsmblob_init(&blob, osid);
> +			rc = security_filter_rule_match(&blob,
>  							rule->lsm[i].type,
>  							Audit_equal,
>  							rule->lsm[i].rule);
> @@ -345,7 +347,8 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  		case LSM_SUBJ_USER:
>  		case LSM_SUBJ_ROLE:
>  		case LSM_SUBJ_TYPE:
> -			rc = security_filter_rule_match(secid,
> +			lsmblob_init(&blob, secid);
> +			rc = security_filter_rule_match(&blob,
>  							rule->lsm[i].type,
>  							Audit_equal,
>  							rule->lsm[i].rule);
> diff --git a/security/security.c b/security/security.c
> index 7618c761060d..4692f44718c6 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2452,9 +2452,19 @@ void security_audit_rule_free(void *lsmrule)
>  	call_void_hook(audit_rule_free, lsmrule);
>  }
>  
> -int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
> +int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
> +			      void *lsmrule)
>  {
> -	return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule);
> +	struct security_hook_list *hp;
> +	int rc;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) {
> +		rc = hp->hook.audit_rule_match(blob->secid[hp->slot], field,
> +					       op, lsmrule);
> +		if (rc != 0)
> +			return rc;
> +	}
> +	return 0;
>  }
>  #endif /* CONFIG_AUDIT */
>  
> 






^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 07/24] net: Prepare UDS for secuirty module stacking
  2019-06-21 18:52 ` [PATCH v3 07/24] net: Prepare UDS for secuirty module stacking Casey Schaufler
  2019-06-22 22:43   ` Kees Cook
@ 2019-06-24 18:39   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:39 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change the data used in UDS SO_PEERSEC processing from a
> secid to a more general struct lsmblob. Update the
> security_socket_getpeersec_dgram() interface to use the
> lsmblob. There is a small amount of scaffolding code
> that will come out when the security_secid_to_secctx()
> code is brought in line with the lsmblob.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  include/linux/security.h |  7 +++++--
>  include/net/af_unix.h    |  2 +-
>  include/net/scm.h        |  8 +++++---
>  net/ipv4/ip_sockglue.c   |  8 +++++---
>  net/unix/af_unix.c       |  6 +++---
>  security/security.c      | 16 +++++++++++++---
>  6 files changed, 32 insertions(+), 15 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 4a78516cc74a..905830a90745 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -1276,7 +1276,8 @@ int security_socket_shutdown(struct socket *sock, int how);
>  int security_sock_rcv_skb(struct sock *sk, struct sk_buff *skb);
>  int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
>  				      int __user *optlen, unsigned len);
> -int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid);
> +int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
> +				     struct lsmblob *blob);
>  int security_sk_alloc(struct sock *sk, int family, gfp_t priority);
>  void security_sk_free(struct sock *sk);
>  void security_sk_clone(const struct sock *sk, struct sock *newsk);
> @@ -1414,7 +1415,9 @@ static inline int security_socket_getpeersec_stream(struct socket *sock, char __
>  	return -ENOPROTOOPT;
>  }
>  
> -static inline int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
> +static inline int security_socket_getpeersec_dgram(struct socket *sock,
> +						   struct sk_buff *skb,
> +						   struct lsmblob *blob)
>  {
>  	return -ENOPROTOOPT;
>  }
> diff --git a/include/net/af_unix.h b/include/net/af_unix.h
> index 3426d6dacc45..933492c08b8c 100644
> --- a/include/net/af_unix.h
> +++ b/include/net/af_unix.h
> @@ -36,7 +36,7 @@ struct unix_skb_parms {
>  	kgid_t			gid;
>  	struct scm_fp_list	*fp;		/* Passed files		*/
>  #ifdef CONFIG_SECURITY_NETWORK
> -	u32			secid;		/* Security ID		*/
> +	struct lsmblob		lsmblob;	/* Security LSM data	*/
>  #endif
>  	u32			consumed;
>  } __randomize_layout;
> diff --git a/include/net/scm.h b/include/net/scm.h
> index 1ce365f4c256..e2e71c4bf9d0 100644
> --- a/include/net/scm.h
> +++ b/include/net/scm.h
> @@ -33,7 +33,7 @@ struct scm_cookie {
>  	struct scm_fp_list	*fp;		/* Passed files		*/
>  	struct scm_creds	creds;		/* Skb credentials	*/
>  #ifdef CONFIG_SECURITY_NETWORK
> -	u32			secid;		/* Passed security ID 	*/
> +	struct lsmblob		lsmblob;	/* Passed LSM data	*/
>  #endif
>  };
>  
> @@ -46,7 +46,7 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl);
>  #ifdef CONFIG_SECURITY_NETWORK
>  static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
>  {
> -	security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
> +	security_socket_getpeersec_dgram(sock, NULL, &scm->lsmblob);
>  }
>  #else
>  static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
> @@ -97,7 +97,9 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
>  	int err;
>  
>  	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
> -		err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
> +		/* Scaffolding - it has to be element 0 for now */
> +		err = security_secid_to_secctx(scm->lsmblob.secid[0],
> +					       &secdata, &seclen);
>  
>  		if (!err) {
>  			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index 82f341e84fae..2a5c868ce135 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -130,15 +130,17 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
>  
>  static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
>  {
> +	struct lsmblob lb;
>  	char *secdata;
> -	u32 seclen, secid;
> +	u32 seclen;
>  	int err;
>  
> -	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
> +	err = security_socket_getpeersec_dgram(NULL, skb, &lb);
>  	if (err)
>  		return;
>  
> -	err = security_secid_to_secctx(secid, &secdata, &seclen);
> +	/* Scaffolding - it has to be element 0 */
> +	err = security_secid_to_secctx(lb.secid[0], &secdata, &seclen);
>  	if (err)
>  		return;
>  
> diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
> index ddb838a1b74c..c50a004a1389 100644
> --- a/net/unix/af_unix.c
> +++ b/net/unix/af_unix.c
> @@ -143,17 +143,17 @@ static struct hlist_head *unix_sockets_unbound(void *addr)
>  #ifdef CONFIG_SECURITY_NETWORK
>  static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
>  {
> -	UNIXCB(skb).secid = scm->secid;
> +	UNIXCB(skb).lsmblob = scm->lsmblob;
>  }
>  
>  static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
>  {
> -	scm->secid = UNIXCB(skb).secid;
> +	scm->lsmblob = UNIXCB(skb).lsmblob;
>  }
>  
>  static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
>  {
> -	return (scm->secid == UNIXCB(skb).secid);
> +	return lsmblob_equal(&scm->lsmblob, &(UNIXCB(skb).lsmblob));
>  }
>  #else
>  static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
> diff --git a/security/security.c b/security/security.c
> index 43f8018b9e13..c7b3d1a294ad 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2137,10 +2137,20 @@ int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
>  				optval, optlen, len);
>  }
>  
> -int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
> +int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
> +				     struct lsmblob *blob)
>  {
> -	return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock,
> -			     skb, secid);
> +	struct security_hook_list *hp;
> +	int rc = -ENOPROTOOPT;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_dgram,
> +			     list) {
> +		rc = hp->hook.socket_getpeersec_dgram(sock, skb,
> +						      &blob->secid[hp->slot]);
> +		if (rc != 0)
> +			break;
> +	}
> +	return rc;
>  }
>  EXPORT_SYMBOL(security_socket_getpeersec_dgram);
>  
> 






^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 09/24] LSM: Use lsmblob in security_secid_to_secctx
  2019-06-21 18:52 ` [PATCH v3 09/24] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
  2019-06-22 22:44   ` Kees Cook
@ 2019-06-24 18:39   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:39 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change security_secid_to_secctx() to take a lsmblob as input
> instead of a u32 secid. It will then call the LSM hooks
> using the lsmblob element allocated for that module. The
> callers have been updated as well. This allows for the
> possibility that more than one module may called upon
> to translate a secid to a string, as can occur in the
> audit code.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  drivers/android/binder.c                |  4 +++-
>  include/linux/security.h                |  5 +++--
>  include/net/scm.h                       |  5 ++---
>  kernel/audit.c                          |  9 +++++++--
>  kernel/auditsc.c                        | 14 ++++++++++----
>  net/ipv4/ip_sockglue.c                  |  3 +--
>  net/netfilter/nf_conntrack_netlink.c    |  8 ++++++--
>  net/netfilter/nf_conntrack_standalone.c |  4 +++-
>  net/netfilter/nfnetlink_queue.c         |  8 ++++++--
>  net/netlabel/netlabel_unlabeled.c       | 18 ++++++++++++++----
>  net/netlabel/netlabel_user.c            |  6 +++---
>  security/security.c                     | 14 +++++++++++---
>  12 files changed, 69 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 8685882da64c..1962f6b8abd0 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -3120,9 +3120,11 @@ static void binder_transaction(struct binder_proc *proc,
>  
>  	if (target_node && target_node->txn_security_ctx) {
>  		u32 secid;
> +		struct lsmblob blob;
>  
>  		security_task_getsecid(proc->tsk, &secid);
> -		ret = security_secid_to_secctx(secid, &secctx, &secctx_sz);
> +		lsmblob_init(&blob, secid);
> +		ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
>  		if (ret) {
>  			return_error = BR_FAILED_REPLY;
>  			return_error_param = ret;
> diff --git a/include/linux/security.h b/include/linux/security.h
> index b0395d224c43..c6cddeff8a17 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -442,7 +442,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>  			 size_t size);
>  int security_netlink_send(struct sock *sk, struct sk_buff *skb);
>  int security_ismaclabel(const char *name);
> -int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
> +int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
>  int security_secctx_to_secid(const char *secdata, u32 seclen,
>  			     struct lsmblob *blob);
>  void security_release_secctx(char *secdata, u32 seclen);
> @@ -1220,7 +1220,8 @@ static inline int security_ismaclabel(const char *name)
>  	return 0;
>  }
>  
> -static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
> +static inline int security_secid_to_secctx(struct lsmblob *blob,
> +					   char **secdata, u32 *seclen)
>  {
>  	return -EOPNOTSUPP;
>  }
> diff --git a/include/net/scm.h b/include/net/scm.h
> index e2e71c4bf9d0..31ae605fcc0a 100644
> --- a/include/net/scm.h
> +++ b/include/net/scm.h
> @@ -97,9 +97,8 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
>  	int err;
>  
>  	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
> -		/* Scaffolding - it has to be element 0 for now */
> -		err = security_secid_to_secctx(scm->lsmblob.secid[0],
> -					       &secdata, &seclen);
> +		err = security_secid_to_secctx(&scm->lsmblob, &secdata,
> +					       &seclen);
>  
>  		if (!err) {
>  			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
> diff --git a/kernel/audit.c b/kernel/audit.c
> index c89ea48c70a6..d0338411d75d 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -1430,7 +1430,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
>  	case AUDIT_SIGNAL_INFO:
>  		len = 0;
>  		if (audit_sig_sid) {
> -			err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
> +			struct lsmblob blob;
> +
> +			lsmblob_init(&blob, audit_sig_sid);
> +			err = security_secid_to_secctx(&blob, &ctx, &len);
>  			if (err)
>  				return err;
>  		}
> @@ -2073,12 +2076,14 @@ int audit_log_task_context(struct audit_buffer *ab)
>  	unsigned len;
>  	int error;
>  	u32 sid;
> +	struct lsmblob blob;
>  
>  	security_task_getsecid(current, &sid);
>  	if (!sid)
>  		return 0;
>  
> -	error = security_secid_to_secctx(sid, &ctx, &len);
> +	lsmblob_init(&blob, sid);
> +	error = security_secid_to_secctx(&blob, &ctx, &len);
>  	if (error) {
>  		if (error != -EINVAL)
>  			goto error_path;
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 18ee5556c086..d31914088a82 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -947,6 +947,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  	char *ctx = NULL;
>  	u32 len;
>  	int rc = 0;
> +	struct lsmblob blob;
>  
>  	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
>  	if (!ab)
> @@ -956,7 +957,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  			 from_kuid(&init_user_ns, auid),
>  			 from_kuid(&init_user_ns, uid), sessionid);
>  	if (sid) {
> -		if (security_secid_to_secctx(sid, &ctx, &len)) {
> +		lsmblob_init(&blob, sid);
> +		if (security_secid_to_secctx(&blob, &ctx, &len)) {
>  			audit_log_format(ab, " obj=(none)");
>  			rc = 1;
>  		} else {
> @@ -1198,7 +1200,10 @@ static void show_special(struct audit_context *context, int *call_panic)
>  		if (osid) {
>  			char *ctx = NULL;
>  			u32 len;
> -			if (security_secid_to_secctx(osid, &ctx, &len)) {
> +			struct lsmblob blob;
> +
> +			lsmblob_init(&blob, osid);
> +			if (security_secid_to_secctx(&blob, &ctx, &len)) {
>  				audit_log_format(ab, " osid=%u", osid);
>  				*call_panic = 1;
>  			} else {
> @@ -1349,9 +1354,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
>  	if (n->osid != 0) {
>  		char *ctx = NULL;
>  		u32 len;
> +		struct lsmblob blob;
>  
> -		if (security_secid_to_secctx(
> -			n->osid, &ctx, &len)) {
> +		lsmblob_init(&blob, n->osid);
> +		if (security_secid_to_secctx(&blob, &ctx, &len)) {
>  			audit_log_format(ab, " osid=%u", n->osid);
>  			if (call_panic)
>  				*call_panic = 2;
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index 2a5c868ce135..e05f4ef68bd8 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -139,8 +139,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
>  	if (err)
>  		return;
>  
> -	/* Scaffolding - it has to be element 0 */
> -	err = security_secid_to_secctx(lb.secid[0], &secdata, &seclen);
> +	err = security_secid_to_secctx(&lb, &secdata, &seclen);
>  	if (err)
>  		return;
>  
> diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
> index 66c596d287a5..ca0968f13240 100644
> --- a/net/netfilter/nf_conntrack_netlink.c
> +++ b/net/netfilter/nf_conntrack_netlink.c
> @@ -330,8 +330,10 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
>  	struct nlattr *nest_secctx;
>  	int len, ret;
>  	char *secctx;
> +	struct lsmblob blob;
>  
> -	ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
> +	lsmblob_init(&blob, ct->secmark);
> +	ret = security_secid_to_secctx(&blob, &secctx, &len);
>  	if (ret)
>  		return 0;
>  
> @@ -615,8 +617,10 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
>  {
>  #ifdef CONFIG_NF_CONNTRACK_SECMARK
>  	int len, ret;
> +	struct lsmblob blob;
>  
> -	ret = security_secid_to_secctx(ct->secmark, NULL, &len);
> +	lsmblob_init(&blob, ct->secmark);
> +	ret = security_secid_to_secctx(&blob, NULL, &len);
>  	if (ret)
>  		return 0;
>  
> diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
> index c2ae14c720b4..c793103f3cd7 100644
> --- a/net/netfilter/nf_conntrack_standalone.c
> +++ b/net/netfilter/nf_conntrack_standalone.c
> @@ -175,8 +175,10 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
>  	int ret;
>  	u32 len;
>  	char *secctx;
> +	struct lsmblob blob;
>  
> -	ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
> +	lsmblob_init(&blob, ct->secmark);
> +	ret = security_secid_to_secctx(&blob, &secctx, &len);
>  	if (ret)
>  		return;
>  
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index 0dcc3592d053..59211bff90ab 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -309,13 +309,17 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
>  {
>  	u32 seclen = 0;
>  #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
> +	struct lsmblob blob;
> +
>  	if (!skb || !sk_fullsock(skb->sk))
>  		return 0;
>  
>  	read_lock_bh(&skb->sk->sk_callback_lock);
>  
> -	if (skb->secmark)
> -		security_secid_to_secctx(skb->secmark, secdata, &seclen);
> +	if (skb->secmark) {
> +		lsmblob_init(&blob, skb->secmark);
> +		security_secid_to_secctx(&blob, secdata, &seclen);
> +	}
>  
>  	read_unlock_bh(&skb->sk->sk_callback_lock);
>  #endif
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 2976370e41aa..2d8dd5b84457 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -389,6 +389,7 @@ int netlbl_unlhsh_add(struct net *net,
>  	struct audit_buffer *audit_buf = NULL;
>  	char *secctx = NULL;
>  	u32 secctx_len;
> +	struct lsmblob blob;
>  
>  	if (addr_len != sizeof(struct in_addr) &&
>  	    addr_len != sizeof(struct in6_addr))
> @@ -451,7 +452,8 @@ int netlbl_unlhsh_add(struct net *net,
>  unlhsh_add_return:
>  	rcu_read_unlock();
>  	if (audit_buf != NULL) {
> -		if (security_secid_to_secctx(secid,
> +		lsmblob_init(&blob, secid);
> +		if (security_secid_to_secctx(&blob,
>  					     &secctx,
>  					     &secctx_len) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> @@ -488,6 +490,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  	struct net_device *dev;
>  	char *secctx;
>  	u32 secctx_len;
> +	struct lsmblob blob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
>  	list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
> @@ -507,8 +510,10 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  					  addr->s_addr, mask->s_addr);
>  		if (dev != NULL)
>  			dev_put(dev);
> +		if (entry != NULL)
> +			lsmblob_init(&blob, entry->secid);
>  		if (entry != NULL &&
> -		    security_secid_to_secctx(entry->secid,
> +		    security_secid_to_secctx(&blob,
>  					     &secctx, &secctx_len) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
>  			security_release_secctx(secctx, secctx_len);
> @@ -550,6 +555,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  	struct net_device *dev;
>  	char *secctx;
>  	u32 secctx_len;
> +	struct lsmblob blob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
>  	list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
> @@ -568,8 +574,10 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  					  addr, mask);
>  		if (dev != NULL)
>  			dev_put(dev);
> +		if (entry != NULL)
> +			lsmblob_init(&blob, entry->secid);
>  		if (entry != NULL &&
> -		    security_secid_to_secctx(entry->secid,
> +		    security_secid_to_secctx(&blob,
>  					     &secctx, &secctx_len) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
>  			security_release_secctx(secctx, secctx_len);
> @@ -1090,6 +1098,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  	u32 secid;
>  	char *secctx;
>  	u32 secctx_len;
> +	struct lsmblob blob;
>  
>  	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
>  			   cb_arg->seq, &netlbl_unlabel_gnl_family,
> @@ -1144,7 +1153,8 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  		secid = addr6->secid;
>  	}
>  
> -	ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
> +	lsmblob_init(&blob, secid);
> +	ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
>  	if (ret_val != 0)
>  		goto list_cb_failure;
>  	ret_val = nla_put(cb_arg->skb,
> diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
> index 4676f5bb16ae..2ccc6567e2a2 100644
> --- a/net/netlabel/netlabel_user.c
> +++ b/net/netlabel/netlabel_user.c
> @@ -100,6 +100,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>  	struct audit_buffer *audit_buf;
>  	char *secctx;
>  	u32 secctx_len;
> +	struct lsmblob blob;
>  
>  	if (audit_enabled == AUDIT_OFF)
>  		return NULL;
> @@ -112,10 +113,9 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>  			 from_kuid(&init_user_ns, audit_info->loginuid),
>  			 audit_info->sessionid);
>  
> +	lsmblob_init(&blob, audit_info->secid);
>  	if (audit_info->secid != 0 &&
> -	    security_secid_to_secctx(audit_info->secid,
> -				     &secctx,
> -				     &secctx_len) == 0) {
> +	    security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
>  		audit_log_format(audit_buf, " subj=%s", secctx);
>  		security_release_secctx(secctx, secctx_len);
>  	}
> diff --git a/security/security.c b/security/security.c
> index cb1545bfe8c5..5ab07631df75 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1992,10 +1992,18 @@ int security_ismaclabel(const char *name)
>  }
>  EXPORT_SYMBOL(security_ismaclabel);
>  
> -int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
> +int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
>  {
> -	return call_int_hook(secid_to_secctx, -EOPNOTSUPP, secid, secdata,
> -				seclen);
> +	struct security_hook_list *hp;
> +	int rc;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
> +		rc = hp->hook.secid_to_secctx(blob->secid[hp->slot],
> +					      secdata, seclen);
> +		if (rc != 0)
> +			return rc;
> +	}
> +	return 0;
>  }
>  EXPORT_SYMBOL(security_secid_to_secctx);
>  
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 10/24] Use lsmblob in security_ipc_getsecid
  2019-06-21 18:52 ` [PATCH v3 10/24] Use lsmblob in security_ipc_getsecid Casey Schaufler
  2019-06-22 22:48   ` Kees Cook
@ 2019-06-24 18:39   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:39 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> There may be more than one LSM that provides IPC data
> for auditing. Change security_ipc_getsecid() to fill in
> a lsmblob structure instead of the u32 secid. The
> audit data structure containing the secid will be updated
> later, so there is a bit of scaffolding here.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  include/linux/security.h | 7 ++++---
>  kernel/auditsc.c         | 5 ++++-
>  security/security.c      | 9 ++++++---
>  3 files changed, 14 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index c6cddeff8a17..0d5e172341fc 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -413,7 +413,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
>  			unsigned long arg4, unsigned long arg5);
>  void security_task_to_inode(struct task_struct *p, struct inode *inode);
>  int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
> -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid);
> +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob);
>  int security_msg_msg_alloc(struct msg_msg *msg);
>  void security_msg_msg_free(struct msg_msg *msg);
>  int security_msg_queue_alloc(struct kern_ipc_perm *msq);
> @@ -1098,9 +1098,10 @@ static inline int security_ipc_permission(struct kern_ipc_perm *ipcp,
>  	return 0;
>  }
>  
> -static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
> +static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp,
> +					 struct lsmblob *blob)
>  {
> -	*secid = 0;
> +	lsmblob_init(blob, 0);
>  }
>  
>  static inline int security_msg_msg_alloc(struct msg_msg *msg)
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index d31914088a82..148733ec3c72 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -2268,11 +2268,14 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
>  void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
>  {
>  	struct audit_context *context = audit_context();
> +	struct lsmblob blob;
>  	context->ipc.uid = ipcp->uid;
>  	context->ipc.gid = ipcp->gid;
>  	context->ipc.mode = ipcp->mode;
>  	context->ipc.has_perm = 0;
> -	security_ipc_getsecid(ipcp, &context->ipc.osid);
> +	security_ipc_getsecid(ipcp, &blob);
> +	/* scaffolding on the [0] - change "osid" to a lsmblob */
> +	context->ipc.osid = blob.secid[0];
>  	context->type = AUDIT_IPC;
>  }
>  
> diff --git a/security/security.c b/security/security.c
> index 5ab07631df75..d55f01041f05 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1812,10 +1812,13 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
>  	return call_int_hook(ipc_permission, 0, ipcp, flag);
>  }
>  
> -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
> +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob)
>  {
> -	*secid = 0;
> -	call_void_hook(ipc_getsecid, ipcp, secid);
> +	struct security_hook_list *hp;
> +
> +	lsmblob_init(blob, 0);
> +	hlist_for_each_entry(hp, &security_hook_heads.ipc_getsecid, list)
> +		hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->slot]);
>  }
>  
>  int security_msg_msg_alloc(struct msg_msg *msg)
> 


^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 11/24] LSM: Use lsmblob in security_task_getsecid
  2019-06-21 18:52 ` [PATCH v3 11/24] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
  2019-06-22 22:49   ` Kees Cook
@ 2019-06-24 18:40   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:40 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change the security_task_getsecid() interface to fill in
> a lsmblob structure instead of a u32 secid in support of
> LSM stacking. Audit interfaces will need to collect all
> possible secids for possible reporting.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Review-by: John Johansen <john.johansen@canonical.com>

> ---
>  drivers/android/binder.c              |  4 +---
>  include/linux/security.h              |  7 +++---
>  kernel/audit.c                        |  6 ++---
>  kernel/auditfilter.c                  |  4 +---
>  kernel/auditsc.c                      | 22 ++++++++++++------
>  net/netlabel/netlabel_unlabeled.c     |  5 +++-
>  net/netlabel/netlabel_user.h          |  6 ++++-
>  security/integrity/ima/ima_appraise.c |  4 +++-
>  security/integrity/ima/ima_main.c     | 33 +++++++++++++++------------
>  security/security.c                   |  9 +++++---
>  10 files changed, 60 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 1962f6b8abd0..144ac4f1c24f 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -3119,11 +3119,9 @@ static void binder_transaction(struct binder_proc *proc,
>  	t->priority = task_nice(current);
>  
>  	if (target_node && target_node->txn_security_ctx) {
> -		u32 secid;
>  		struct lsmblob blob;
>  
> -		security_task_getsecid(proc->tsk, &secid);
> -		lsmblob_init(&blob, secid);
> +		security_task_getsecid(proc->tsk, &blob);
>  		ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
>  		if (ret) {
>  			return_error = BR_FAILED_REPLY;
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 0d5e172341fc..c5fdaaff8806 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -396,7 +396,7 @@ int security_task_fix_setuid(struct cred *new, const struct cred *old,
>  int security_task_setpgid(struct task_struct *p, pid_t pgid);
>  int security_task_getpgid(struct task_struct *p);
>  int security_task_getsid(struct task_struct *p);
> -void security_task_getsecid(struct task_struct *p, u32 *secid);
> +void security_task_getsecid(struct task_struct *p, struct lsmblob *blob);
>  int security_task_setnice(struct task_struct *p, int nice);
>  int security_task_setioprio(struct task_struct *p, int ioprio);
>  int security_task_getioprio(struct task_struct *p);
> @@ -1025,9 +1025,10 @@ static inline int security_task_getsid(struct task_struct *p)
>  	return 0;
>  }
>  
> -static inline void security_task_getsecid(struct task_struct *p, u32 *secid)
> +static inline void security_task_getsecid(struct task_struct *p,
> +					  struct lsmblob *blob)
>  {
> -	*secid = 0;
> +	lsmblob_init(blob, 0);
>  }
>  
>  static inline int security_task_setnice(struct task_struct *p, int nice)
> diff --git a/kernel/audit.c b/kernel/audit.c
> index d0338411d75d..a0205f3c23c7 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -2075,14 +2075,12 @@ int audit_log_task_context(struct audit_buffer *ab)
>  	char *ctx = NULL;
>  	unsigned len;
>  	int error;
> -	u32 sid;
>  	struct lsmblob blob;
>  
> -	security_task_getsecid(current, &sid);
> -	if (!sid)
> +	security_task_getsecid(current, &blob);
> +	if (!lsmblob_is_set(&blob))
>  		return 0;
>  
> -	lsmblob_init(&blob, sid);
>  	error = security_secid_to_secctx(&blob, &ctx, &len);
>  	if (error) {
>  		if (error != -EINVAL)
> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> index da211065160f..76b4c0ca4fd2 100644
> --- a/kernel/auditfilter.c
> +++ b/kernel/auditfilter.c
> @@ -1323,7 +1323,6 @@ int audit_filter(int msgtype, unsigned int listtype)
>  		for (i = 0; i < e->rule.field_count; i++) {
>  			struct audit_field *f = &e->rule.fields[i];
>  			pid_t pid;
> -			u32 sid;
>  			struct lsmblob blob;
>  
>  			switch (f->type) {
> @@ -1354,8 +1353,7 @@ int audit_filter(int msgtype, unsigned int listtype)
>  			case AUDIT_SUBJ_SEN:
>  			case AUDIT_SUBJ_CLR:
>  				if (f->lsm_rule) {
> -					security_task_getsecid(current, &sid);
> -					lsmblob_init(&blob, sid);
> +					security_task_getsecid(current, &blob);
>  					result = security_audit_rule_match(&blob,
>  						   f->type, f->op, f->lsm_rule);
>  				}
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 148733ec3c72..7112fe31684d 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -444,7 +444,6 @@ static int audit_filter_rules(struct task_struct *tsk,
>  {
>  	const struct cred *cred;
>  	int i, need_sid = 1;
> -	u32 sid;
>  	struct lsmblob blob;
>  	unsigned int sessionid;
>  
> @@ -628,10 +627,9 @@ static int audit_filter_rules(struct task_struct *tsk,
>  			   logged upon error */
>  			if (f->lsm_rule) {
>  				if (need_sid) {
> -					security_task_getsecid(tsk, &sid);
> +					security_task_getsecid(tsk, &blob);
>  					need_sid = 0;
>  				}
> -				lsmblob_init(&blob, sid);
>  				result = security_audit_rule_match(&blob,
>  								   f->type,
>  								   f->op,
> @@ -2365,12 +2363,15 @@ int __audit_sockaddr(int len, void *a)
>  void __audit_ptrace(struct task_struct *t)
>  {
>  	struct audit_context *context = audit_context();
> +	struct lsmblob blob;
>  
>  	context->target_pid = task_tgid_nr(t);
>  	context->target_auid = audit_get_loginuid(t);
>  	context->target_uid = task_uid(t);
>  	context->target_sessionid = audit_get_sessionid(t);
> -	security_task_getsecid(t, &context->target_sid);
> +	security_task_getsecid(t, &blob);
> +	/* scaffolding - until target_sid is converted */
> +	context->target_sid = blob.secid[0];
>  	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
>  }
>  
> @@ -2387,6 +2388,7 @@ int audit_signal_info(int sig, struct task_struct *t)
>  	struct audit_aux_data_pids *axp;
>  	struct audit_context *ctx = audit_context();
>  	kuid_t uid = current_uid(), auid, t_uid = task_uid(t);
> +	struct lsmblob blob;
>  
>  	if (auditd_test_task(t) &&
>  	    (sig == SIGTERM || sig == SIGHUP ||
> @@ -2397,7 +2399,9 @@ int audit_signal_info(int sig, struct task_struct *t)
>  			audit_sig_uid = auid;
>  		else
>  			audit_sig_uid = uid;
> -		security_task_getsecid(current, &audit_sig_sid);
> +		security_task_getsecid(current, &blob);
> +		/* scaffolding until audit_sig_sid is converted */
> +		audit_sig_sid = blob.secid[0];
>  	}
>  
>  	if (!audit_signals || audit_dummy_context())
> @@ -2410,7 +2414,9 @@ int audit_signal_info(int sig, struct task_struct *t)
>  		ctx->target_auid = audit_get_loginuid(t);
>  		ctx->target_uid = t_uid;
>  		ctx->target_sessionid = audit_get_sessionid(t);
> -		security_task_getsecid(t, &ctx->target_sid);
> +		security_task_getsecid(t, &blob);
> +		/* scaffolding until target_sid is converted */
> +		ctx->target_sid = blob.secid[0];
>  		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
>  		return 0;
>  	}
> @@ -2431,7 +2437,9 @@ int audit_signal_info(int sig, struct task_struct *t)
>  	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
>  	axp->target_uid[axp->pid_count] = t_uid;
>  	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
> -	security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
> +	security_task_getsecid(t, &blob);
> +	/* scaffolding until target_sid is converted */
> +	axp->target_sid[axp->pid_count] = blob.secid[0];
>  	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
>  	axp->pid_count++;
>  
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 2d8dd5b84457..2294aa9471e6 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -1552,11 +1552,14 @@ int __init netlbl_unlabel_defconf(void)
>  	int ret_val;
>  	struct netlbl_dom_map *entry;
>  	struct netlbl_audit audit_info;
> +	struct lsmblob blob;
>  
>  	/* Only the kernel is allowed to call this function and the only time
>  	 * it is called is at bootup before the audit subsystem is reporting
>  	 * messages so don't worry to much about these values. */
> -	security_task_getsecid(current, &audit_info.secid);
> +	security_task_getsecid(current, &blob);
> +	/* scaffolding until audit_info.secid is converted */
> +	audit_info.secid = blob.secid[0];
>  	audit_info.loginuid = GLOBAL_ROOT_UID;
>  	audit_info.sessionid = 0;
>  
> diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
> index 4a397cde1a48..ab88baaaa50d 100644
> --- a/net/netlabel/netlabel_user.h
> +++ b/net/netlabel/netlabel_user.h
> @@ -48,7 +48,11 @@
>  static inline void netlbl_netlink_auditinfo(struct sk_buff *skb,
>  					    struct netlbl_audit *audit_info)
>  {
> -	security_task_getsecid(current, &audit_info->secid);
> +	struct lsmblob blob;
> +
> +	security_task_getsecid(current, &blob);
> +	/* scaffolding until secid is converted */
> +	audit_info->secid = blob.secid[0];
>  	audit_info->loginuid = audit_get_loginuid(current);
>  	audit_info->sessionid = audit_get_sessionid(current);
>  }
> diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
> index 5fb7127bbe68..85c7692fc4a3 100644
> --- a/security/integrity/ima/ima_appraise.c
> +++ b/security/integrity/ima/ima_appraise.c
> @@ -51,11 +51,13 @@ bool is_ima_appraise_enabled(void)
>  int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
>  {
>  	u32 secid;
> +	struct lsmblob blob;
>  
>  	if (!ima_appraise)
>  		return 0;
>  
> -	security_task_getsecid(current, &secid);
> +	security_task_getsecid(current, &blob);
> +	lsmblob_secid(&blob, &secid);
>  	return ima_match_policy(inode, current_cred(), secid, func, mask,
>  				IMA_APPRAISE | IMA_HASH, NULL);
>  }
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 357edd140c09..fefa848cf0c7 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -335,12 +335,13 @@ static int process_measurement(struct file *file, const struct cred *cred,
>   */
>  int ima_file_mmap(struct file *file, unsigned long prot)
>  {
> -	u32 secid;
> +	struct lsmblob blob;
>  
>  	if (file && (prot & PROT_EXEC)) {
> -		security_task_getsecid(current, &secid);
> -		return process_measurement(file, current_cred(), secid, NULL,
> -					   0, MAY_EXEC, MMAP_CHECK);
> +		security_task_getsecid(current, &blob);
> +		/* scaffolding - until process_measurement changes */
> +		return process_measurement(file, current_cred(), blob.secid[0],
> +					   NULL, 0, MAY_EXEC, MMAP_CHECK);
>  	}
>  
>  	return 0;
> @@ -363,10 +364,12 @@ int ima_bprm_check(struct linux_binprm *bprm)
>  {
>  	int ret;
>  	u32 secid;
> +	struct lsmblob blob;
>  
> -	security_task_getsecid(current, &secid);
> -	ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0,
> -				  MAY_EXEC, BPRM_CHECK);
> +	security_task_getsecid(current, &blob);
> +	/* scaffolding until process_measurement changes */
> +	ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
> +				  NULL, 0, MAY_EXEC, BPRM_CHECK);
>  	if (ret)
>  		return ret;
>  
> @@ -387,10 +390,11 @@ int ima_bprm_check(struct linux_binprm *bprm)
>   */
>  int ima_file_check(struct file *file, int mask)
>  {
> -	u32 secid;
> +	struct lsmblob blob;
>  
> -	security_task_getsecid(current, &secid);
> -	return process_measurement(file, current_cred(), secid, NULL, 0,
> +	security_task_getsecid(current, &blob);
> +	/* scaffolding until process_measurement changes */
> +	return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
>  				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
>  					   MAY_APPEND), FILE_CHECK);
>  }
> @@ -499,7 +503,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
>  		       enum kernel_read_file_id read_id)
>  {
>  	enum ima_hooks func;
> -	u32 secid;
> +	struct lsmblob blob;
>  
>  	if (!file && read_id == READING_FIRMWARE) {
>  		if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
> @@ -521,9 +525,10 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
>  	}
>  
>  	func = read_idmap[read_id] ?: FILE_CHECK;
> -	security_task_getsecid(current, &secid);
> -	return process_measurement(file, current_cred(), secid, buf, size,
> -				   MAY_READ, func);
> +	security_task_getsecid(current, &blob);
> +	/* scaffolding until process_measurement changes */
> +	return process_measurement(file, current_cred(), blob.secid[0], buf,
> +				   size, MAY_READ, func);
>  }
>  
>  /**
> diff --git a/security/security.c b/security/security.c
> index d55f01041f05..1184ef092bce 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1729,10 +1729,13 @@ int security_task_getsid(struct task_struct *p)
>  	return call_int_hook(task_getsid, 0, p);
>  }
>  
> -void security_task_getsecid(struct task_struct *p, u32 *secid)
> +void security_task_getsecid(struct task_struct *p, struct lsmblob *blob)
>  {
> -	*secid = 0;
> -	call_void_hook(task_getsecid, p, secid);
> +	struct security_hook_list *hp;
> +
> +	lsmblob_init(blob, 0);
> +	hlist_for_each_entry(hp, &security_hook_heads.task_getsecid, list)
> +		hp->hook.task_getsecid(p, &blob->secid[hp->slot]);
>  }
>  EXPORT_SYMBOL(security_task_getsecid);
>  
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 12/24] LSM: Use lsmblob in security_inode_getsecid
  2019-06-21 18:52 ` [PATCH v3 12/24] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
  2019-06-22 22:49   ` Kees Cook
@ 2019-06-24 18:40   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:40 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change the security_inode_getsecid() interface to fill in a
> lsmblob structure instead of a u32 secid. This allows for its
> callers to gather data from all registered LSMs. Data is provided
> for IMA and audit.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  include/linux/security.h            | 7 ++++---
>  kernel/auditsc.c                    | 6 +++++-
>  security/integrity/ima/ima_policy.c | 4 +---
>  security/security.c                 | 8 ++++++--
>  4 files changed, 16 insertions(+), 9 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index c5fdaaff8806..6eb64b7f878a 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -358,7 +358,7 @@ int security_inode_killpriv(struct dentry *dentry);
>  int security_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc);
>  int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags);
>  int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size);
> -void security_inode_getsecid(struct inode *inode, u32 *secid);
> +void security_inode_getsecid(struct inode *inode, struct lsmblob *blob);
>  int security_inode_copy_up(struct dentry *src, struct cred **new);
>  int security_inode_copy_up_xattr(const char *name);
>  int security_file_permission(struct file *file, int mask);
> @@ -854,9 +854,10 @@ static inline int security_inode_listsecurity(struct inode *inode, char *buffer,
>  	return 0;
>  }
>  
> -static inline void security_inode_getsecid(struct inode *inode, u32 *secid)
> +static inline void security_inode_getsecid(struct inode *inode,
> +					   struct lsmblob *blob)
>  {
> -	*secid = 0;
> +	lsmblob_init(blob, 0);
>  }
>  
>  static inline int security_inode_copy_up(struct dentry *src, struct cred **new)
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 7112fe31684d..54797c0fc3b7 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -1910,13 +1910,17 @@ static inline int audit_copy_fcaps(struct audit_names *name,
>  void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
>  		      struct inode *inode, unsigned int flags)
>  {
> +	struct lsmblob blob;
> +
>  	name->ino   = inode->i_ino;
>  	name->dev   = inode->i_sb->s_dev;
>  	name->mode  = inode->i_mode;
>  	name->uid   = inode->i_uid;
>  	name->gid   = inode->i_gid;
>  	name->rdev  = inode->i_rdev;
> -	security_inode_getsecid(inode, &name->osid);
> +	security_inode_getsecid(inode, &blob);
> +	/* scaffolding until osid is updated */
> +	name->osid = blob.secid[0];
>  	if (flags & AUDIT_INODE_NOEVAL) {
>  		name->fcap_ver = -1;
>  		return;
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index e7b8ce942950..92ee3d984c73 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -326,7 +326,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  		return false;
>  	for (i = 0; i < MAX_LSM_RULES; i++) {
>  		int rc = 0;
> -		u32 osid;
>  		struct lsmblob blob;
>  		int retried = 0;
>  
> @@ -337,8 +336,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  		case LSM_OBJ_USER:
>  		case LSM_OBJ_ROLE:
>  		case LSM_OBJ_TYPE:
> -			security_inode_getsecid(inode, &osid);
> -			lsmblob_init(&blob, osid);
> +			security_inode_getsecid(inode, &blob);
>  			rc = security_filter_rule_match(&blob,
>  							rule->lsm[i].type,
>  							Audit_equal,
> diff --git a/security/security.c b/security/security.c
> index 1184ef092bce..6f0635b51180 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1423,9 +1423,13 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer
>  }
>  EXPORT_SYMBOL(security_inode_listsecurity);
>  
> -void security_inode_getsecid(struct inode *inode, u32 *secid)
> +void security_inode_getsecid(struct inode *inode, struct lsmblob *blob)
>  {
> -	call_void_hook(inode_getsecid, inode, secid);
> +	struct security_hook_list *hp;
> +
> +	lsmblob_init(blob, 0);
> +	hlist_for_each_entry(hp, &security_hook_heads.inode_getsecid, list)
> +		hp->hook.inode_getsecid(inode, &blob->secid[hp->slot]);
>  }
>  
>  int security_inode_copy_up(struct dentry *src, struct cred **new)
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 13/24] LSM: Use lsmblob in security_cred_getsecid
  2019-06-21 18:52 ` [PATCH v3 13/24] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
  2019-06-22 22:50   ` Kees Cook
@ 2019-06-24 18:40   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:40 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change the security_cred_getsecid() interface to fill in a
> lsmblob instead of a u32 secid. The associated data elements
> in the audit sub-system are changed from a secid to a lsmblob
> to accomodate multiple possible LSM audit users.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  include/linux/security.h          |  2 +-
>  kernel/audit.c                    | 14 +++++-------
>  kernel/audit.h                    |  5 +++--
>  kernel/auditsc.c                  | 37 +++++++++++--------------------
>  security/integrity/ima/ima_main.c |  8 +++----
>  security/security.c               |  9 +++++---
>  6 files changed, 33 insertions(+), 42 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 6eb64b7f878a..c712fc72b7bd 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -383,7 +383,7 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp);
>  void security_cred_free(struct cred *cred);
>  int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
>  void security_transfer_creds(struct cred *new, const struct cred *old);
> -void security_cred_getsecid(const struct cred *c, u32 *secid);
> +void security_cred_getsecid(const struct cred *c, struct lsmblob *blob);
>  int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
>  int security_kernel_create_files_as(struct cred *new, struct inode *inode);
>  int security_kernel_module_request(char *kmod_name);
> diff --git a/kernel/audit.c b/kernel/audit.c
> index a0205f3c23c7..1b51e907f131 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -137,7 +137,7 @@ static u32	audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
>  /* The identity of the user shutting down the audit system. */
>  kuid_t		audit_sig_uid = INVALID_UID;
>  pid_t		audit_sig_pid = -1;
> -u32		audit_sig_sid = 0;
> +struct lsmblob	audit_sig_lsm;
>  
>  /* Records can be lost in several ways:
>     0) [suppressed in audit_alloc]
> @@ -1429,23 +1429,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
>  	}
>  	case AUDIT_SIGNAL_INFO:
>  		len = 0;
> -		if (audit_sig_sid) {
> -			struct lsmblob blob;
> -
> -			lsmblob_init(&blob, audit_sig_sid);
> -			err = security_secid_to_secctx(&blob, &ctx, &len);
> +		if (lsmblob_is_set(&audit_sig_lsm)) {
> +			err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
> +						       &len);
>  			if (err)
>  				return err;
>  		}
>  		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
>  		if (!sig_data) {
> -			if (audit_sig_sid)
> +			if (lsmblob_is_set(&audit_sig_lsm))
>  				security_release_secctx(ctx, len);
>  			return -ENOMEM;
>  		}
>  		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
>  		sig_data->pid = audit_sig_pid;
> -		if (audit_sig_sid) {
> +		if (lsmblob_is_set(&audit_sig_lsm)) {
>  			memcpy(sig_data->ctx, ctx, len);
>  			security_release_secctx(ctx, len);
>  		}
> diff --git a/kernel/audit.h b/kernel/audit.h
> index 958d5b8fc1b3..29e29c6f4afb 100644
> --- a/kernel/audit.h
> +++ b/kernel/audit.h
> @@ -22,6 +22,7 @@
>  #include <linux/fs.h>
>  #include <linux/audit.h>
>  #include <linux/skbuff.h>
> +#include <linux/security.h>
>  #include <uapi/linux/mqueue.h>
>  #include <linux/tty.h>
>  
> @@ -147,7 +148,7 @@ struct audit_context {
>  	kuid_t		    target_auid;
>  	kuid_t		    target_uid;
>  	unsigned int	    target_sessionid;
> -	u32		    target_sid;
> +	struct lsmblob   target_lsm;
>  	char		    target_comm[TASK_COMM_LEN];
>  
>  	struct audit_tree_refs *trees, *first_trees;
> @@ -338,7 +339,7 @@ extern char *audit_unpack_string(void **bufp, size_t *remain, size_t len);
>  
>  extern pid_t audit_sig_pid;
>  extern kuid_t audit_sig_uid;
> -extern u32 audit_sig_sid;
> +extern struct lsmblob audit_sig_lsm;
>  
>  extern int audit_filter(int msgtype, unsigned int listtype);
>  
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 54797c0fc3b7..c7aa39bda5cc 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -112,7 +112,7 @@ struct audit_aux_data_pids {
>  	kuid_t			target_auid[AUDIT_AUX_PIDS];
>  	kuid_t			target_uid[AUDIT_AUX_PIDS];
>  	unsigned int		target_sessionid[AUDIT_AUX_PIDS];
> -	u32			target_sid[AUDIT_AUX_PIDS];
> +	struct lsmblob	target_lsm[AUDIT_AUX_PIDS];
>  	char 			target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
>  	int			pid_count;
>  };
> @@ -938,14 +938,14 @@ static inline void audit_free_context(struct audit_context *context)
>  }
>  
>  static int audit_log_pid_context(struct audit_context *context, pid_t pid,
> -				 kuid_t auid, kuid_t uid, unsigned int sessionid,
> -				 u32 sid, char *comm)
> +				 kuid_t auid, kuid_t uid,
> +				 unsigned int sessionid,
> +				 struct lsmblob *blob, char *comm)
>  {
>  	struct audit_buffer *ab;
>  	char *ctx = NULL;
>  	u32 len;
>  	int rc = 0;
> -	struct lsmblob blob;
>  
>  	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
>  	if (!ab)
> @@ -954,9 +954,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
>  			 from_kuid(&init_user_ns, auid),
>  			 from_kuid(&init_user_ns, uid), sessionid);
> -	if (sid) {
> -		lsmblob_init(&blob, sid);
> -		if (security_secid_to_secctx(&blob, &ctx, &len)) {
> +	if (lsmblob_is_set(blob)) {
> +		if (security_secid_to_secctx(blob, &ctx, &len)) {
>  			audit_log_format(ab, " obj=(none)");
>  			rc = 1;
>  		} else {
> @@ -1527,7 +1526,7 @@ static void audit_log_exit(void)
>  						  axs->target_auid[i],
>  						  axs->target_uid[i],
>  						  axs->target_sessionid[i],
> -						  axs->target_sid[i],
> +						  &axs->target_lsm[i],
>  						  axs->target_comm[i]))
>  				call_panic = 1;
>  	}
> @@ -1536,7 +1535,7 @@ static void audit_log_exit(void)
>  	    audit_log_pid_context(context, context->target_pid,
>  				  context->target_auid, context->target_uid,
>  				  context->target_sessionid,
> -				  context->target_sid, context->target_comm))
> +				  &context->target_lsm, context->target_comm))
>  			call_panic = 1;
>  
>  	if (context->pwd.dentry && context->pwd.mnt) {
> @@ -1713,7 +1712,7 @@ void __audit_syscall_exit(int success, long return_code)
>  	context->aux = NULL;
>  	context->aux_pids = NULL;
>  	context->target_pid = 0;
> -	context->target_sid = 0;
> +	lsmblob_init(&context->target_lsm, 0);
>  	context->sockaddr_len = 0;
>  	context->type = 0;
>  	context->fds[0] = -1;
> @@ -2367,15 +2366,12 @@ int __audit_sockaddr(int len, void *a)
>  void __audit_ptrace(struct task_struct *t)
>  {
>  	struct audit_context *context = audit_context();
> -	struct lsmblob blob;
>  
>  	context->target_pid = task_tgid_nr(t);
>  	context->target_auid = audit_get_loginuid(t);
>  	context->target_uid = task_uid(t);
>  	context->target_sessionid = audit_get_sessionid(t);
> -	security_task_getsecid(t, &blob);
> -	/* scaffolding - until target_sid is converted */
> -	context->target_sid = blob.secid[0];
> +	security_task_getsecid(t, &context->target_lsm);
>  	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
>  }
>  
> @@ -2392,7 +2388,6 @@ int audit_signal_info(int sig, struct task_struct *t)
>  	struct audit_aux_data_pids *axp;
>  	struct audit_context *ctx = audit_context();
>  	kuid_t uid = current_uid(), auid, t_uid = task_uid(t);
> -	struct lsmblob blob;
>  
>  	if (auditd_test_task(t) &&
>  	    (sig == SIGTERM || sig == SIGHUP ||
> @@ -2403,9 +2398,7 @@ int audit_signal_info(int sig, struct task_struct *t)
>  			audit_sig_uid = auid;
>  		else
>  			audit_sig_uid = uid;
> -		security_task_getsecid(current, &blob);
> -		/* scaffolding until audit_sig_sid is converted */
> -		audit_sig_sid = blob.secid[0];
> +		security_task_getsecid(current, &audit_sig_lsm);
>  	}
>  
>  	if (!audit_signals || audit_dummy_context())
> @@ -2418,9 +2411,7 @@ int audit_signal_info(int sig, struct task_struct *t)
>  		ctx->target_auid = audit_get_loginuid(t);
>  		ctx->target_uid = t_uid;
>  		ctx->target_sessionid = audit_get_sessionid(t);
> -		security_task_getsecid(t, &blob);
> -		/* scaffolding until target_sid is converted */
> -		ctx->target_sid = blob.secid[0];
> +		security_task_getsecid(t, &ctx->target_lsm);
>  		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
>  		return 0;
>  	}
> @@ -2441,9 +2432,7 @@ int audit_signal_info(int sig, struct task_struct *t)
>  	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
>  	axp->target_uid[axp->pid_count] = t_uid;
>  	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
> -	security_task_getsecid(t, &blob);
> -	/* scaffolding until target_sid is converted */
> -	axp->target_sid[axp->pid_count] = blob.secid[0];
> +	security_task_getsecid(t, &axp->target_lsm[axp->pid_count]);
>  	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
>  	axp->pid_count++;
>  
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index fefa848cf0c7..1afb75a893af 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -363,7 +363,6 @@ int ima_file_mmap(struct file *file, unsigned long prot)
>  int ima_bprm_check(struct linux_binprm *bprm)
>  {
>  	int ret;
> -	u32 secid;
>  	struct lsmblob blob;
>  
>  	security_task_getsecid(current, &blob);
> @@ -373,9 +372,10 @@ int ima_bprm_check(struct linux_binprm *bprm)
>  	if (ret)
>  		return ret;
>  
> -	security_cred_getsecid(bprm->cred, &secid);
> -	return process_measurement(bprm->file, bprm->cred, secid, NULL, 0,
> -				   MAY_EXEC, CREDS_CHECK);
> +	security_cred_getsecid(bprm->cred, &blob);
> +	/* scaffolding until process_measurement changes */
> +	return process_measurement(bprm->file, bprm->cred, blob.secid[0],
> +				   NULL, 0, MAY_EXEC, CREDS_CHECK);
>  }
>  
>  /**
> diff --git a/security/security.c b/security/security.c
> index 6f0635b51180..aa8e1c73a062 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1643,10 +1643,13 @@ void security_transfer_creds(struct cred *new, const struct cred *old)
>  	call_void_hook(cred_transfer, new, old);
>  }
>  
> -void security_cred_getsecid(const struct cred *c, u32 *secid)
> +void security_cred_getsecid(const struct cred *c, struct lsmblob *blob)
>  {
> -	*secid = 0;
> -	call_void_hook(cred_getsecid, c, secid);
> +	struct security_hook_list *hp;
> +
> +	lsmblob_init(blob, 0);
> +	hlist_for_each_entry(hp, &security_hook_heads.cred_getsecid, list)
> +		hp->hook.cred_getsecid(c, &blob->secid[hp->slot]);
>  }
>  EXPORT_SYMBOL(security_cred_getsecid);
>  
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 14/24] IMA: Change internal interfaces to use lsmblobs
  2019-06-21 18:52 ` [PATCH v3 14/24] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
  2019-06-22 22:51   ` Kees Cook
@ 2019-06-24 18:40   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:40 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> The IMA interfaces ima_get_action() and ima_match_policy()
> call LSM functions that use lsmblobs. Change the IMA functions
> to pass the lsmblob to be compatible with the LSM functions.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

assuming you have the typo fix Kees already pointed out

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  security/integrity/ima/ima.h          | 10 ++++++----
>  security/integrity/ima/ima_api.c      |  9 +++++----
>  security/integrity/ima/ima_appraise.c |  4 +---
>  security/integrity/ima/ima_main.c     | 27 +++++++++++----------------
>  security/integrity/ima/ima_policy.c   | 12 ++++++------
>  5 files changed, 29 insertions(+), 33 deletions(-)
> 
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index 5a337239d9e4..73b3b15dec5c 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -192,8 +192,9 @@ enum ima_hooks {
>  };
>  
>  /* LIM API function definitions */
> -int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
> -		   int mask, enum ima_hooks func, int *pcr);
> +int ima_get_action(struct inode *inode, const struct cred *cred,
> +		   struct lsmblob *blob, int mask, enum ima_hooks func,
> +		   int *pcr);
>  int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
>  int ima_collect_measurement(struct integrity_iint_cache *iint,
>  			    struct file *file, void *buf, loff_t size,
> @@ -213,8 +214,9 @@ void ima_free_template_entry(struct ima_template_entry *entry);
>  const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
>  
>  /* IMA policy related functions */
> -int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
> -		     enum ima_hooks func, int mask, int flags, int *pcr);
> +int ima_match_policy(struct inode *inode, const struct cred *cred,
> +		     struct lsmblob *blob, enum ima_hooks func, int mask,
> +		     int flags, int *pcr);
>  void ima_init_policy(void);
>  void ima_update_policy(void);
>  void ima_update_policy_flag(void);
> diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
> index c7505fb122d4..03a2392852de 100644
> --- a/security/integrity/ima/ima_api.c
> +++ b/security/integrity/ima/ima_api.c
> @@ -159,7 +159,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
>   * ima_get_action - appraise & measure decision based on policy.
>   * @inode: pointer to inode to measure
>   * @cred: pointer to credentials structure to validate
> - * @secid: secid of the task being validated
> + * @blob: LAM data of the task being validated
>   * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC,
>   *        MAY_APPEND)
>   * @func: caller identifier
> @@ -175,14 +175,15 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
>   * Returns IMA_MEASURE, IMA_APPRAISE mask.
>   *
>   */
> -int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
> -		   int mask, enum ima_hooks func, int *pcr)
> +int ima_get_action(struct inode *inode, const struct cred *cred,
> +		   struct lsmblob *blob, int mask, enum ima_hooks func,
> +		   int *pcr)
>  {
>  	int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH;
>  
>  	flags &= ima_policy_flag;
>  
> -	return ima_match_policy(inode, cred, secid, func, mask, flags, pcr);
> +	return ima_match_policy(inode, cred, blob, func, mask, flags, pcr);
>  }
>  
>  /*
> diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
> index 85c7692fc4a3..3ff7aae81829 100644
> --- a/security/integrity/ima/ima_appraise.c
> +++ b/security/integrity/ima/ima_appraise.c
> @@ -50,15 +50,13 @@ bool is_ima_appraise_enabled(void)
>   */
>  int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
>  {
> -	u32 secid;
>  	struct lsmblob blob;
>  
>  	if (!ima_appraise)
>  		return 0;
>  
>  	security_task_getsecid(current, &blob);
> -	lsmblob_secid(&blob, &secid);
> -	return ima_match_policy(inode, current_cred(), secid, func, mask,
> +	return ima_match_policy(inode, current_cred(), &blob, func, mask,
>  				IMA_APPRAISE | IMA_HASH, NULL);
>  }
>  
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 1afb75a893af..0588dd9a88db 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -169,8 +169,8 @@ void ima_file_free(struct file *file)
>  }
>  
>  static int process_measurement(struct file *file, const struct cred *cred,
> -			       u32 secid, char *buf, loff_t size, int mask,
> -			       enum ima_hooks func)
> +			       struct lsmblob *blob, char *buf, loff_t size,
> +			       int mask, enum ima_hooks func)
>  {
>  	struct inode *inode = file_inode(file);
>  	struct integrity_iint_cache *iint = NULL;
> @@ -192,7 +192,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
>  	 * bitmask based on the appraise/audit/measurement policy.
>  	 * Included is the appraise submask.
>  	 */
> -	action = ima_get_action(inode, cred, secid, mask, func, &pcr);
> +	action = ima_get_action(inode, cred, blob, mask, func, &pcr);
>  	violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
>  			   (ima_policy_flag & IMA_MEASURE));
>  	if (!action && !violation_check)
> @@ -339,8 +339,7 @@ int ima_file_mmap(struct file *file, unsigned long prot)
>  
>  	if (file && (prot & PROT_EXEC)) {
>  		security_task_getsecid(current, &blob);
> -		/* scaffolding - until process_measurement changes */
> -		return process_measurement(file, current_cred(), blob.secid[0],
> +		return process_measurement(file, current_cred(), &blob,
>  					   NULL, 0, MAY_EXEC, MMAP_CHECK);
>  	}
>  
> @@ -366,16 +365,14 @@ int ima_bprm_check(struct linux_binprm *bprm)
>  	struct lsmblob blob;
>  
>  	security_task_getsecid(current, &blob);
> -	/* scaffolding until process_measurement changes */
> -	ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
> -				  NULL, 0, MAY_EXEC, BPRM_CHECK);
> +	ret = process_measurement(bprm->file, current_cred(), &blob, NULL, 0,
> +				  MAY_EXEC, BPRM_CHECK);
>  	if (ret)
>  		return ret;
>  
>  	security_cred_getsecid(bprm->cred, &blob);
> -	/* scaffolding until process_measurement changes */
> -	return process_measurement(bprm->file, bprm->cred, blob.secid[0],
> -				   NULL, 0, MAY_EXEC, CREDS_CHECK);
> +	return process_measurement(bprm->file, bprm->cred, &blob, NULL, 0,
> +				   MAY_EXEC, CREDS_CHECK);
>  }
>  
>  /**
> @@ -393,8 +390,7 @@ int ima_file_check(struct file *file, int mask)
>  	struct lsmblob blob;
>  
>  	security_task_getsecid(current, &blob);
> -	/* scaffolding until process_measurement changes */
> -	return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
> +	return process_measurement(file, current_cred(), &blob, NULL, 0,
>  				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
>  					   MAY_APPEND), FILE_CHECK);
>  }
> @@ -526,9 +522,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
>  
>  	func = read_idmap[read_id] ?: FILE_CHECK;
>  	security_task_getsecid(current, &blob);
> -	/* scaffolding until process_measurement changes */
> -	return process_measurement(file, current_cred(), blob.secid[0], buf,
> -				   size, MAY_READ, func);
> +	return process_measurement(file, current_cred(), &blob, buf, size,
> +				   MAY_READ, func);
>  }
>  
>  /**
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index 92ee3d984c73..dbad256aa7b4 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -286,7 +286,7 @@ static void ima_lsm_update_rules(void)
>   * Returns true on rule match, false on failure.
>   */
>  static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
> -			    const struct cred *cred, u32 secid,
> +			    const struct cred *cred, struct lsmblob *blob,
>  			    enum ima_hooks func, int mask)
>  {
>  	int i;
> @@ -345,7 +345,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
>  		case LSM_SUBJ_USER:
>  		case LSM_SUBJ_ROLE:
>  		case LSM_SUBJ_TYPE:
> -			lsmblob_init(&blob, secid);
>  			rc = security_filter_rule_match(&blob,
>  							rule->lsm[i].type,
>  							Audit_equal,
> @@ -394,7 +393,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
>   * @inode: pointer to an inode for which the policy decision is being made
>   * @cred: pointer to a credentials structure for which the policy decision is
>   *        being made
> - * @secid: LSM secid of the task to be validated
> + * @blob: LSM data of the task to be validated
>   * @func: IMA hook identifier
>   * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
>   * @pcr: set the pcr to extend
> @@ -406,8 +405,9 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
>   * list when walking it.  Reads are many orders of magnitude more numerous
>   * than writes so ima_match_policy() is classical RCU candidate.
>   */
> -int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
> -		     enum ima_hooks func, int mask, int flags, int *pcr)
> +int ima_match_policy(struct inode *inode, const struct cred *cred,
> +		     struct lsmblob *blob, enum ima_hooks func, int mask,
> +		     int flags, int *pcr)
>  {
>  	struct ima_rule_entry *entry;
>  	int action = 0, actmask = flags | (flags << 1);
> @@ -418,7 +418,7 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
>  		if (!(entry->action & actmask))
>  			continue;
>  
> -		if (!ima_match_rules(entry, inode, cred, secid, func, mask))
> +		if (!ima_match_rules(entry, inode, cred, blob, func, mask))
>  			continue;
>  
>  		action |= entry->flags & IMA_ACTION_FLAGS;
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 15/24] LSM: Specify which LSM to display
  2019-06-21 18:52 ` [PATCH v3 15/24] LSM: Specify which LSM to display Casey Schaufler
  2019-06-22 22:51   ` Kees Cook
@ 2019-06-24 18:48   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 18:48 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Create a new entry "display" in /proc/.../attr for controlling
> which LSM security information is displayed for a process.
> The name of an active LSM that supplies hooks for human readable
> data may be written to "display" to set the value. The name of
> the LSM currently in use can be read from "display".
> At this point there can only be one LSM capable of display
> active.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>


there is small issue, see below


Also I want to get rid of the list search for the display lsm
but that can come as a separate patch later


> ---
>  fs/proc/base.c      |   1 +
>  security/security.c | 110 +++++++++++++++++++++++++++++++++++---------
>  2 files changed, 90 insertions(+), 21 deletions(-)
> 
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index ddef482f1334..7bf70e041315 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -2618,6 +2618,7 @@ static const struct pid_entry attr_dir_stuff[] = {
>  	ATTR(NULL, "fscreate",		0666),
>  	ATTR(NULL, "keycreate",		0666),
>  	ATTR(NULL, "sockcreate",	0666),
> +	ATTR(NULL, "display",		0666),
>  #ifdef CONFIG_SECURITY_SMACK
>  	DIR("smack",			0555,
>  	    proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
> diff --git a/security/security.c b/security/security.c
> index aa8e1c73a062..92c5aa427b53 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -46,7 +46,9 @@ static struct kmem_cache *lsm_file_cache;
>  static struct kmem_cache *lsm_inode_cache;
>  
>  char *lsm_names;
> -static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init;
> +static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init = {
> +	.lbs_task = sizeof(int),	/* slot number for the "display" LSM */
> +};
>  
>  /* Boot-time LSM user choice */
>  static __initdata const char *chosen_lsm_order;
> @@ -583,6 +585,8 @@ int lsm_inode_alloc(struct inode *inode)
>   */
>  static int lsm_task_alloc(struct task_struct *task)
>  {
> +	int *display;
> +
>  	if (blob_sizes.lbs_task == 0) {
>  		task->security = NULL;
>  		return 0;
> @@ -591,6 +595,15 @@ static int lsm_task_alloc(struct task_struct *task)
>  	task->security = kzalloc(blob_sizes.lbs_task, GFP_KERNEL);
>  	if (task->security == NULL)
>  		return -ENOMEM;
> +
> +	/*
> +	 * The start of the task blob contains the "display" LSM slot number.
> +	 * Start with it set to the invalid slot number, indicating that the
> +	 * default first registered LSM be displayed.
> +	 */
> +	display = task->security;
> +	*display = LSMBLOB_INVALID;
> +
>  	return 0;
>  }
>  
> @@ -1579,14 +1592,24 @@ int security_file_open(struct file *file)
>  
>  int security_task_alloc(struct task_struct *task, unsigned long clone_flags)
>  {
> +	int *odisplay = current->security;
> +	int *ndisplay;
>  	int rc = lsm_task_alloc(task);
>  
> -	if (rc)
> +	if (unlikely(rc))
>  		return rc;
> +
>  	rc = call_int_hook(task_alloc, 0, task, clone_flags);
> -	if (unlikely(rc))
> +	if (unlikely(rc)) {
>  		security_task_free(task);
> -	return rc;
> +		return rc;
> +	}
> +
> +	ndisplay = task->security;
> +	if (ndisplay && odisplay)
> +		*ndisplay = *odisplay;
> +
> +	return 0;
>  }
>  
>  void security_task_free(struct task_struct *task)
> @@ -1972,10 +1995,28 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
>  				char **value)
>  {
>  	struct security_hook_list *hp;
> +	int *display = current->security;
> +
> +	if (!strcmp(name, "display")) {
> +		hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx,
> +				     list) {
> +			if (*display == LSMBLOB_INVALID ||
> +			    hp->slot == *display) {
> +				*value = kstrdup(hp->lsm, GFP_KERNEL);
> +				if (*value)
> +					return strlen(hp->lsm);
> +				return -ENOMEM;
> +			}
> +		}
> +		return -EINVAL;
> +	}
>  
>  	hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
>  		if (lsm != NULL && strcmp(lsm, hp->lsm))
>  			continue;
> +		if (lsm == NULL && *display != LSMBLOB_INVALID &&
> +		    *display != hp->slot)
> +			continue;
>  		return hp->hook.getprocattr(p, name, value);
>  	}
>  	return -EINVAL;
> @@ -1985,10 +2026,27 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>  			 size_t size)
>  {
>  	struct security_hook_list *hp;
> +	int *display = current->security;
> +	int len;
> +
> +	if (!strcmp(name, "display")) {
> +		hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx,
> +				     list) {
> +			len = strlen(hp->lsm);
> +			if (size >= len && !strncmp(value, hp->lsm, len)) {

This isn't quite right. It allows a value that contains a prefix of an lsm to match. That
is
  selinux2
etc would match to selinux. While it isn't a real problem atm. Its not something I
want as part of the user space API which would make it so we can't fix it.




> +				*display = hp->slot;
> +				return size;
> +			}
> +		}
> +		return -EINVAL;
> +	}
>  
>  	hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
>  		if (lsm != NULL && strcmp(lsm, hp->lsm))
>  			continue;
> +		if (lsm == NULL && *display != LSMBLOB_INVALID &&
> +		    *display != hp->slot)
> +			continue;
>  		return hp->hook.setprocattr(name, value, size);
>  	}
>  	return -EINVAL;
> @@ -2008,14 +2066,12 @@ EXPORT_SYMBOL(security_ismaclabel);
>  int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
>  {
>  	struct security_hook_list *hp;
> -	int rc;
> +	int *display = current->security;
>  
> -	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
> -		rc = hp->hook.secid_to_secctx(blob->secid[hp->slot],
> -					      secdata, seclen);
> -		if (rc != 0)
> -			return rc;
> -	}
> +	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list)
> +		if (*display == LSMBLOB_INVALID || *display == hp->slot)
> +			return hp->hook.secid_to_secctx(blob->secid[hp->slot],
> +							secdata, seclen);
>  	return 0;
>  }
>  EXPORT_SYMBOL(security_secid_to_secctx);
> @@ -2024,22 +2080,27 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
>  			     struct lsmblob *blob)
>  {
>  	struct security_hook_list *hp;
> -	int rc;
> +	int *display = current->security;
>  
>  	lsmblob_init(blob, 0);
> -	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
> -		rc = hp->hook.secctx_to_secid(secdata, seclen,
> -					      &blob->secid[hp->slot]);
> -		if (rc != 0)
> -			return rc;
> -	}
> +	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list)
> +		if (*display == LSMBLOB_INVALID || *display == hp->slot)
> +			return hp->hook.secctx_to_secid(secdata, seclen,
> +							&blob->secid[hp->slot]);
>  	return 0;
>  }
>  EXPORT_SYMBOL(security_secctx_to_secid);
>  
>  void security_release_secctx(char *secdata, u32 seclen)
>  {
> -	call_void_hook(release_secctx, secdata, seclen);
> +	struct security_hook_list *hp;
> +	int *display = current->security;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
> +		if (*display == LSMBLOB_INVALID || *display == hp->slot) {
> +			hp->hook.release_secctx(secdata, seclen);
> +			return;
> +		}
>  }
>  EXPORT_SYMBOL(security_release_secctx);
>  
> @@ -2164,8 +2225,15 @@ EXPORT_SYMBOL(security_sock_rcv_skb);
>  int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
>  				      int __user *optlen, unsigned len)
>  {
> -	return call_int_hook(socket_getpeersec_stream, -ENOPROTOOPT, sock,
> -				optval, optlen, len);
> +	int *display = current->security;
> +	struct security_hook_list *hp;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_stream,
> +			     list)
> +		if (*display == LSMBLOB_INVALID || *display == hp->slot)
> +			return hp->hook.socket_getpeersec_stream(sock, optval,
> +								 optlen, len);
> +	return -ENOPROTOOPT;
>  }
>  
>  int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 10/24] Use lsmblob in security_ipc_getsecid
  2019-06-24 16:39     ` Casey Schaufler
  2019-06-24 17:20       ` Casey Schaufler
@ 2019-06-24 21:09       ` Kees Cook
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-24 21:09 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	john.johansen, penguin-kernel, paul, sds

On Mon, Jun 24, 2019 at 09:39:05AM -0700, Casey Schaufler wrote:
> On 6/22/2019 3:48 PM, Kees Cook wrote:
> > On Fri, Jun 21, 2019 at 11:52:19AM -0700, Casey Schaufler wrote:
> >> +	struct security_hook_list *hp;
> >> +
> >> +	lsmblob_init(blob, 0);
> >> +	hlist_for_each_entry(hp, &security_hook_heads.ipc_getsecid, list)
> >> +		hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->slot]);
> > Just for sanity when using hp->slot, it might be good to do something
> > like this in the places it gets used. Like for here:
> >
> > 	if (!WARN_ON(hp->slot < 0 || hp->slot >= LSMBLOB_COUNT))
> > 		hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->slot]);
> >
> > This _should_ be overkill, but since lists of hooks that trigger slot
> > assignment is hardcoded, it seems nice to cover any future problems or
> > mismatches.
> 
> How about a CONFIG_LSM_SLOT_CHECK around a function lsm_slot_check()?
> If configured, it does the WARN_ON, and if not it's a static inline
> true return. As you say, it's probably overkill, but it would be available
> for the paranoid/debug/bringup situation.

No, this doesn't need another CONFIG. The test is nearly free and WARN
means it's wrapped in an unlikely already. I think just adding it
outright would be fine.

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob
  2019-06-21 18:52 ` [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob Casey Schaufler
  2019-06-22 23:12   ` Kees Cook
@ 2019-06-24 21:33   ` John Johansen
  2019-06-25  1:01     ` Casey Schaufler
  1 sibling, 1 reply; 81+ messages in thread
From: John Johansen @ 2019-06-24 21:33 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds, Eric Paris

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change the audit code to store full lsmblob data instead of
> a single u32 secid. This allows for multiple security modules
> to use the audit system at the same time. It also allows the
> removal of scaffolding code that was included during the
> revision of LSM interfaces.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

I know Kees raised this too, but I haven't seen a reply

Eric (Paul is already CCed): I have directly added you because of
the question below.

In summary there isn't necessarily a single secid any more, and
we need to know whether dropping the logging of the secid or
logging all secids is the correct action.

> ---
>  kernel/audit.h   |  6 +++---
>  kernel/auditsc.c | 38 +++++++++++---------------------------
>  2 files changed, 14 insertions(+), 30 deletions(-)
> 
> diff --git a/kernel/audit.h b/kernel/audit.h
> index 29e29c6f4afb..a8dd479e9556 100644
> --- a/kernel/audit.h
> +++ b/kernel/audit.h
> @@ -91,7 +91,7 @@ struct audit_names {
>  	kuid_t			uid;
>  	kgid_t			gid;
>  	dev_t			rdev;
> -	u32			osid;
> +	struct lsmblob		olsm;
>  	struct audit_cap_data	fcap;
>  	unsigned int		fcap_ver;
>  	unsigned char		type;		/* record type */
> @@ -148,7 +148,7 @@ struct audit_context {
>  	kuid_t		    target_auid;
>  	kuid_t		    target_uid;
>  	unsigned int	    target_sessionid;
> -	struct lsmblob   target_lsm;
> +	struct lsmblob	    target_lsm;
>  	char		    target_comm[TASK_COMM_LEN];
>  
>  	struct audit_tree_refs *trees, *first_trees;
> @@ -165,7 +165,7 @@ struct audit_context {
>  			kuid_t			uid;
>  			kgid_t			gid;
>  			umode_t			mode;
> -			u32			osid;
> +			struct lsmblob		olsm;
>  			int			has_perm;
>  			uid_t			perm_uid;
>  			gid_t			perm_gid;
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 0478680cd0a8..d3ad13f11788 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -646,17 +646,15 @@ static int audit_filter_rules(struct task_struct *tsk,
>  			if (f->lsm_rule) {
>  				/* Find files that match */
>  				if (name) {
> -					lsmblob_init(&blob, name->osid);
>  					result = security_audit_rule_match(
> -								&blob,
> +								&name->olsm,
>  								f->type,
>  								f->op,
>  								f->lsm_rule);
>  				} else if (ctx) {
>  					list_for_each_entry(n, &ctx->names_list, list) {
> -						lsmblob_init(&blob, n->osid);
>  						if (security_audit_rule_match(
> -								&blob,
> +								&n->olsm,
>  								f->type,
>  								f->op,
>  								f->lsm_rule)) {
> @@ -668,8 +666,7 @@ static int audit_filter_rules(struct task_struct *tsk,
>  				/* Find ipc objects that match */
>  				if (!ctx || ctx->type != AUDIT_IPC)
>  					break;
> -				lsmblob_init(&blob, ctx->ipc.osid);
> -				if (security_audit_rule_match(&blob,
> +				if (security_audit_rule_match(&ctx->ipc.olsm,
>  							      f->type, f->op,
>  							      f->lsm_rule))
>  					++result;
> @@ -1187,21 +1184,18 @@ static void show_special(struct audit_context *context, int *call_panic)
>  				context->socketcall.args[i]);
>  		break; }
>  	case AUDIT_IPC: {
> -		u32 osid = context->ipc.osid;
> +		struct lsmblob *olsm = &context->ipc.olsm;
>  
>  		audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
>  				 from_kuid(&init_user_ns, context->ipc.uid),
>  				 from_kgid(&init_user_ns, context->ipc.gid),
>  				 context->ipc.mode);
> -		if (osid) {
> +		if (lsmblob_is_set(olsm)) {
>  			struct lsmcontext lsmcxt;
> -			struct lsmblob blob;
>  
> -			lsmblob_init(&blob, osid);
> -			if (security_secid_to_secctx(&blob, &lsmcxt)) {
> -				audit_log_format(ab, " osid=%u", osid);

I am not comfortable just dropping this I would think logging all secids is the
correct action here.


> +			if (security_secid_to_secctx(olsm, &lsmcxt))
>  				*call_panic = 1;
> -			} else {
> +			else {
>  				audit_log_format(ab, " obj=%s", lsmcxt.context);
>  				security_release_secctx(&lsmcxt);
>  			}
> @@ -1346,13 +1340,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
>  				 from_kgid(&init_user_ns, n->gid),
>  				 MAJOR(n->rdev),
>  				 MINOR(n->rdev));
> -	if (n->osid != 0) {
> -		struct lsmblob blob;
> +	if (lsmblob_is_set(&n->olsm)) {
>  		struct lsmcontext lsmctx;
>  
> -		lsmblob_init(&blob, n->osid);
> -		if (security_secid_to_secctx(&blob, &lsmctx)) {
> -			audit_log_format(ab, " osid=%u", n->osid);

and here


> +		if (security_secid_to_secctx(&n->olsm, &lsmctx)) {
>  			if (call_panic)
>  				*call_panic = 2;
>  		} else {
> @@ -1906,17 +1897,13 @@ static inline int audit_copy_fcaps(struct audit_names *name,
>  void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
>  		      struct inode *inode, unsigned int flags)
>  {
> -	struct lsmblob blob;
> -
>  	name->ino   = inode->i_ino;
>  	name->dev   = inode->i_sb->s_dev;
>  	name->mode  = inode->i_mode;
>  	name->uid   = inode->i_uid;
>  	name->gid   = inode->i_gid;
>  	name->rdev  = inode->i_rdev;
> -	security_inode_getsecid(inode, &blob);
> -	/* scaffolding until osid is updated */
> -	name->osid = blob.secid[0];
> +	security_inode_getsecid(inode, &name->olsm);
>  	if (flags & AUDIT_INODE_NOEVAL) {
>  		name->fcap_ver = -1;
>  		return;
> @@ -2266,14 +2253,11 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
>  void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
>  {
>  	struct audit_context *context = audit_context();
> -	struct lsmblob blob;
>  	context->ipc.uid = ipcp->uid;
>  	context->ipc.gid = ipcp->gid;
>  	context->ipc.mode = ipcp->mode;
>  	context->ipc.has_perm = 0;
> -	security_ipc_getsecid(ipcp, &blob);
> -	/* scaffolding on the [0] - change "osid" to a lsmblob */
> -	context->ipc.osid = blob.secid[0];
> +	security_ipc_getsecid(ipcp, &context->ipc.olsm);
>  	context->type = AUDIT_IPC;
>  }
>  
> 


^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 22/24] LSM: Return the lsmblob slot on initialization
  2019-06-22 23:13   ` Kees Cook
@ 2019-06-24 21:39     ` John Johansen
  2019-06-24 21:50       ` Kees Cook
  2019-06-24 21:53       ` Casey Schaufler
  0 siblings, 2 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 21:39 UTC (permalink / raw)
  To: Kees Cook, Casey Schaufler
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	penguin-kernel, paul, sds

On 6/22/19 4:13 PM, Kees Cook wrote:
> On Fri, Jun 21, 2019 at 11:52:31AM -0700, Casey Schaufler wrote:
>> Return the slot allocated to the calling LSM in the lsmblob
>> structure. This can be used to set lsmblobs explicitly for
>> netlabel interfaces.
>>
>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> 
> (I have some thoughts on refactoring the slot assignment, but that
> should happen after this series -- it's nothing more than a storage
> optimization.)
> 
> -Kees

haha so do I, now I am curious as to how close they align


> 
>> ---
>>  include/linux/lsm_hooks.h  | 4 ++--
>>  security/apparmor/lsm.c    | 8 ++++++--
>>  security/security.c        | 9 +++++++--
>>  security/selinux/hooks.c   | 5 ++++-
>>  security/smack/smack_lsm.c | 5 ++++-
>>  5 files changed, 23 insertions(+), 8 deletions(-)
>>
>> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
>> index 4d1ddf1a2aa6..ce341bcbce5d 100644
>> --- a/include/linux/lsm_hooks.h
>> +++ b/include/linux/lsm_hooks.h
>> @@ -2068,8 +2068,8 @@ struct lsm_blob_sizes {
>>  extern struct security_hook_heads security_hook_heads;
>>  extern char *lsm_names;
>>  
>> -extern void security_add_hooks(struct security_hook_list *hooks, int count,
>> -				char *lsm);
>> +extern int security_add_hooks(struct security_hook_list *hooks, int count,
>> +			      char *lsm);
>>  
>>  #define LSM_FLAG_LEGACY_MAJOR	BIT(0)
>>  #define LSM_FLAG_EXCLUSIVE	BIT(1)
>> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
>> index 2716e7731279..dcbbefbd95ff 100644
>> --- a/security/apparmor/lsm.c
>> +++ b/security/apparmor/lsm.c
>> @@ -47,6 +47,9 @@
>>  /* Flag indicating whether initialization completed */
>>  int apparmor_initialized;
>>  
>> +/* Slot for the AppArmor secid in the lsmblob structure */
>> +int apparmor_lsmblob_slot;
>> +
>>  DEFINE_PER_CPU(struct aa_buffers, aa_buffers);
>>  
>>  
>> @@ -1678,8 +1681,9 @@ static int __init apparmor_init(void)
>>  		aa_free_root_ns();
>>  		goto buffers_out;
>>  	}
>> -	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
>> -				"apparmor");
>> +	apparmor_lsmblob_slot = security_add_hooks(apparmor_hooks,
>> +						   ARRAY_SIZE(apparmor_hooks),
>> +						   "apparmor");
>>  
>>  	/* Report that AppArmor successfully initialized */
>>  	apparmor_initialized = 1;
>> diff --git a/security/security.c b/security/security.c
>> index b2ffcd1f3057..c93a368b697b 100644
>> --- a/security/security.c
>> +++ b/security/security.c
>> @@ -437,9 +437,12 @@ static int lsm_slot __initdata;
>>   * Each LSM has to register its hooks with the infrastructure.
>>   * If the LSM is using hooks that export secids allocate a slot
>>   * for it in the lsmblob.
>> + *
>> + * Returns the slot number in the lsmblob structure if one is
>> + * allocated or LSMBLOB_INVALID if one was not allocated.
>>   */
>> -void __init security_add_hooks(struct security_hook_list *hooks, int count,
>> -				char *lsm)
>> +int __init security_add_hooks(struct security_hook_list *hooks, int count,
>> +			      char *lsm)
>>  {
>>  	int slot = LSMBLOB_INVALID;
>>  	int i;
>> @@ -479,6 +482,8 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
>>  	}
>>  	if (lsm_append(lsm, &lsm_names) < 0)
>>  		panic("%s - Cannot get early memory.\n", __func__);
>> +
>> +	return slot;
>>  }
>>  
>>  int call_lsm_notifier(enum lsm_event event, void *data)
>> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
>> index ee840fecfebb..1e09acbf9630 100644
>> --- a/security/selinux/hooks.c
>> +++ b/security/selinux/hooks.c
>> @@ -103,6 +103,7 @@
>>  #include "avc_ss.h"
>>  
>>  struct selinux_state selinux_state;
>> +int selinux_lsmblob_slot;
>>  
>>  /* SECMARK reference count */
>>  static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
>> @@ -6877,7 +6878,9 @@ static __init int selinux_init(void)
>>  
>>  	hashtab_cache_init();
>>  
>> -	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
>> +	selinux_lsmblob_slot = security_add_hooks(selinux_hooks,
>> +						  ARRAY_SIZE(selinux_hooks),
>> +						  "selinux");
>>  
>>  	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
>>  		panic("SELinux: Unable to register AVC netcache callback\n");
>> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
>> index 3834b751d1e9..273f311fb153 100644
>> --- a/security/smack/smack_lsm.c
>> +++ b/security/smack/smack_lsm.c
>> @@ -60,6 +60,7 @@ static LIST_HEAD(smk_ipv6_port_list);
>>  #endif
>>  static struct kmem_cache *smack_inode_cache;
>>  int smack_enabled;
>> +int smack_lsmblob_slot;
>>  
>>  #define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
>>  static struct {
>> @@ -4749,7 +4750,9 @@ static __init int smack_init(void)
>>  	/*
>>  	 * Register with LSM
>>  	 */
>> -	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
>> +	smack_lsmblob_slot = security_add_hooks(smack_hooks,
>> +						ARRAY_SIZE(smack_hooks),
>> +						"smack");
>>  	smack_enabled = 1;
>>  
>>  	pr_info("Smack:  Initializing.\n");
>> -- 
>> 2.20.1
>>
> 


^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 23/24] NET: Store LSM netlabel data in a lsmblob
  2019-06-21 18:52 ` [PATCH v3 23/24] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
  2019-06-22 23:15   ` Kees Cook
@ 2019-06-24 21:44   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 21:44 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Netlabel uses LSM interfaces requiring an lsmblob and
> the internal storage is used to pass information between
> these interfaces, so change the internal data from a secid
> to a lsmblob. Update the netlabel interfaces and their
> callers to accomodate the change.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canomical.com>

> ---
>  include/net/netlabel.h              |  8 ++--
>  net/ipv4/cipso_ipv4.c               |  6 ++-
>  net/netlabel/netlabel_kapi.c        |  6 +--
>  net/netlabel/netlabel_unlabeled.c   | 57 +++++++++++------------------
>  net/netlabel/netlabel_unlabeled.h   |  2 +-
>  security/selinux/include/security.h |  1 +
>  security/selinux/netlabel.c         |  2 +-
>  security/selinux/ss/services.c      |  4 +-
>  security/smack/smack.h              |  1 +
>  security/smack/smack_lsm.c          |  3 +-
>  security/smack/smackfs.c            | 10 +++--
>  11 files changed, 48 insertions(+), 52 deletions(-)
> 
> diff --git a/include/net/netlabel.h b/include/net/netlabel.h
> index 72d6435fc16c..6c550455e69f 100644
> --- a/include/net/netlabel.h
> +++ b/include/net/netlabel.h
> @@ -180,7 +180,7 @@ struct netlbl_lsm_catmap {
>   * @attr.mls: MLS sensitivity label
>   * @attr.mls.cat: MLS category bitmap
>   * @attr.mls.lvl: MLS sensitivity level
> - * @attr.secid: LSM specific secid token
> + * @attr.lsmblob: LSM specific data
>   *
>   * Description:
>   * This structure is used to pass security attributes between NetLabel and the
> @@ -215,7 +215,7 @@ struct netlbl_lsm_secattr {
>  			struct netlbl_lsm_catmap *cat;
>  			u32 lvl;
>  		} mls;
> -		u32 secid;
> +		struct lsmblob lsmblob;
>  	} attr;
>  };
>  
> @@ -429,7 +429,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
>  				const void *addr,
>  				const void *mask,
>  				u16 family,
> -				u32 secid,
> +				struct lsmblob *lsmblob,
>  				struct netlbl_audit *audit_info);
>  int netlbl_cfg_unlbl_static_del(struct net *net,
>  				const char *dev_name,
> @@ -537,7 +537,7 @@ static inline int netlbl_cfg_unlbl_static_add(struct net *net,
>  					      const void *addr,
>  					      const void *mask,
>  					      u16 family,
> -					      u32 secid,
> +					      struct lsmblob *lsmblob,
>  					      struct netlbl_audit *audit_info)
>  {
>  	return -ENOSYS;
> diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
> index f0165c5f376b..eb4939f38a14 100644
> --- a/net/ipv4/cipso_ipv4.c
> +++ b/net/ipv4/cipso_ipv4.c
> @@ -1481,7 +1481,8 @@ static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
>  
>  	buffer[0] = CIPSO_V4_TAG_LOCAL;
>  	buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
> -	*(u32 *)&buffer[2] = secattr->attr.secid;
> +	/* only one netlabel user - the first */
> +	*(u32 *)&buffer[2] = secattr->attr.lsmblob.secid[0];
>  
>  	return CIPSO_V4_TAG_LOC_BLEN;
>  }
> @@ -1501,7 +1502,8 @@ static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
>  				 const unsigned char *tag,
>  				 struct netlbl_lsm_secattr *secattr)
>  {
> -	secattr->attr.secid = *(u32 *)&tag[2];
> +	/* only one netlabel user - the first */
> +	secattr->attr.lsmblob.secid[0] = *(u32 *)&tag[2];
>  	secattr->flags |= NETLBL_SECATTR_SECID;
>  
>  	return 0;
> diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
> index ee3e5b6471a6..724d44943543 100644
> --- a/net/netlabel/netlabel_kapi.c
> +++ b/net/netlabel/netlabel_kapi.c
> @@ -210,7 +210,7 @@ int netlbl_cfg_unlbl_map_add(const char *domain,
>   * @addr: IP address in network byte order (struct in[6]_addr)
>   * @mask: address mask in network byte order (struct in[6]_addr)
>   * @family: address family
> - * @secid: LSM secid value for the entry
> + * @lsmblob: LSM data value for the entry
>   * @audit_info: NetLabel audit information
>   *
>   * Description:
> @@ -224,7 +224,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
>  				const void *addr,
>  				const void *mask,
>  				u16 family,
> -				u32 secid,
> +				struct lsmblob *lsmblob,
>  				struct netlbl_audit *audit_info)
>  {
>  	u32 addr_len;
> @@ -244,7 +244,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
>  
>  	return netlbl_unlhsh_add(net,
>  				 dev_name, addr, mask, addr_len,
> -				 secid, audit_info);
> +				 lsmblob, audit_info);
>  }
>  
>  /**
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 4716e0011ba5..57ede7781c8f 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -80,7 +80,7 @@ struct netlbl_unlhsh_tbl {
>  #define netlbl_unlhsh_addr4_entry(iter) \
>  	container_of(iter, struct netlbl_unlhsh_addr4, list)
>  struct netlbl_unlhsh_addr4 {
> -	u32 secid;
> +	struct lsmblob lsmblob;
>  
>  	struct netlbl_af4list list;
>  	struct rcu_head rcu;
> @@ -88,7 +88,7 @@ struct netlbl_unlhsh_addr4 {
>  #define netlbl_unlhsh_addr6_entry(iter) \
>  	container_of(iter, struct netlbl_unlhsh_addr6, list)
>  struct netlbl_unlhsh_addr6 {
> -	u32 secid;
> +	struct lsmblob lsmblob;
>  
>  	struct netlbl_af6list list;
>  	struct rcu_head rcu;
> @@ -233,7 +233,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
>   * @iface: the associated interface entry
>   * @addr: IPv4 address in network byte order
>   * @mask: IPv4 address mask in network byte order
> - * @secid: LSM secid value for entry
> + * @lsmblob: LSM data value for entry
>   *
>   * Description:
>   * Add a new address entry into the unlabeled connection hash table using the
> @@ -244,7 +244,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
>  static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
>  				   const struct in_addr *addr,
>  				   const struct in_addr *mask,
> -				   u32 secid)
> +				   struct lsmblob *lsmblob)
>  {
>  	int ret_val;
>  	struct netlbl_unlhsh_addr4 *entry;
> @@ -256,7 +256,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
>  	entry->list.addr = addr->s_addr & mask->s_addr;
>  	entry->list.mask = mask->s_addr;
>  	entry->list.valid = 1;
> -	entry->secid = secid;
> +	entry->lsmblob = *lsmblob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
>  	ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);
> @@ -273,7 +273,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
>   * @iface: the associated interface entry
>   * @addr: IPv6 address in network byte order
>   * @mask: IPv6 address mask in network byte order
> - * @secid: LSM secid value for entry
> + * @lsmblob: LSM data value for entry
>   *
>   * Description:
>   * Add a new address entry into the unlabeled connection hash table using the
> @@ -284,7 +284,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
>  static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
>  				   const struct in6_addr *addr,
>  				   const struct in6_addr *mask,
> -				   u32 secid)
> +				   struct lsmblob *lsmblob)
>  {
>  	int ret_val;
>  	struct netlbl_unlhsh_addr6 *entry;
> @@ -300,7 +300,7 @@ static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
>  	entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
>  	entry->list.mask = *mask;
>  	entry->list.valid = 1;
> -	entry->secid = secid;
> +	entry->lsmblob = *lsmblob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
>  	ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);
> @@ -379,7 +379,7 @@ int netlbl_unlhsh_add(struct net *net,
>  		      const void *addr,
>  		      const void *mask,
>  		      u32 addr_len,
> -		      u32 secid,
> +		      struct lsmblob *lsmblob,
>  		      struct netlbl_audit *audit_info)
>  {
>  	int ret_val;
> @@ -388,7 +388,6 @@ int netlbl_unlhsh_add(struct net *net,
>  	struct netlbl_unlhsh_iface *iface;
>  	struct audit_buffer *audit_buf = NULL;
>  	struct lsmcontext context;
> -	struct lsmblob blob;
>  
>  	if (addr_len != sizeof(struct in_addr) &&
>  	    addr_len != sizeof(struct in6_addr))
> @@ -421,7 +420,7 @@ int netlbl_unlhsh_add(struct net *net,
>  		const struct in_addr *addr4 = addr;
>  		const struct in_addr *mask4 = mask;
>  
> -		ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
> +		ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, lsmblob);
>  		if (audit_buf != NULL)
>  			netlbl_af4list_audit_addr(audit_buf, 1,
>  						  dev_name,
> @@ -434,7 +433,7 @@ int netlbl_unlhsh_add(struct net *net,
>  		const struct in6_addr *addr6 = addr;
>  		const struct in6_addr *mask6 = mask;
>  
> -		ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
> +		ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, lsmblob);
>  		if (audit_buf != NULL)
>  			netlbl_af6list_audit_addr(audit_buf, 1,
>  						  dev_name,
> @@ -451,8 +450,7 @@ int netlbl_unlhsh_add(struct net *net,
>  unlhsh_add_return:
>  	rcu_read_unlock();
>  	if (audit_buf != NULL) {
> -		lsmblob_init(&blob, secid);
> -		if (security_secid_to_secctx(&blob, &context) == 0) {
> +		if (security_secid_to_secctx(lsmblob, &context) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s",
>  					 context.context);
>  			security_release_secctx(&context);
> @@ -487,7 +485,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  	struct audit_buffer *audit_buf;
>  	struct net_device *dev;
>  	struct lsmcontext context;
> -	struct lsmblob blob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
>  	list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
> @@ -507,10 +504,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  					  addr->s_addr, mask->s_addr);
>  		if (dev != NULL)
>  			dev_put(dev);
> -		if (entry != NULL)
> -			lsmblob_init(&blob, entry->secid);
>  		if (entry != NULL &&
> -		    security_secid_to_secctx(&blob, &context) == 0) {
> +		    security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s",
>  					 context.context);
>  			security_release_secctx(&context);
> @@ -551,7 +546,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  	struct audit_buffer *audit_buf;
>  	struct net_device *dev;
>  	struct lsmcontext context;
> -	struct lsmblob blob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
>  	list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
> @@ -570,10 +564,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  					  addr, mask);
>  		if (dev != NULL)
>  			dev_put(dev);
> -		if (entry != NULL)
> -			lsmblob_init(&blob, entry->secid);
>  		if (entry != NULL &&
> -		    security_secid_to_secctx(&blob, &context) == 0) {
> +		    security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s",
>  					 context.context);
>  			security_release_secctx(&context);
> @@ -927,9 +919,8 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
>  	if (ret_val != 0)
>  		return ret_val;
>  
> -	/* scaffolding with the [0] */
>  	return netlbl_unlhsh_add(&init_net,
> -				 dev_name, addr, mask, addr_len, blob.secid[0],
> +				 dev_name, addr, mask, addr_len, &blob,
>  				 &audit_info);
>  }
>  
> @@ -977,10 +968,8 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
>  	if (ret_val != 0)
>  		return ret_val;
>  
> -	/* scaffolding with the [0] */
>  	return netlbl_unlhsh_add(&init_net,
> -				 NULL, addr, mask, addr_len, blob.secid[0],
> -				 &audit_info);
> +				 NULL, addr, mask, addr_len, &blob, &audit_info);
>  }
>  
>  /**
> @@ -1092,8 +1081,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  	struct net_device *dev;
>  	struct lsmcontext context;
>  	void *data;
> -	u32 secid;
> -	struct lsmblob blob;
> +	struct lsmblob *lsmb;
>  
>  	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
>  			   cb_arg->seq, &netlbl_unlabel_gnl_family,
> @@ -1131,7 +1119,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  		if (ret_val != 0)
>  			goto list_cb_failure;
>  
> -		secid = addr4->secid;
> +		lsmb = (struct lsmblob *)&addr4->lsmblob;
>  	} else {
>  		ret_val = nla_put_in6_addr(cb_arg->skb,
>  					   NLBL_UNLABEL_A_IPV6ADDR,
> @@ -1145,11 +1133,10 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  		if (ret_val != 0)
>  			goto list_cb_failure;
>  
> -		secid = addr6->secid;
> +		lsmb = (struct lsmblob *)&addr6->lsmblob;
>  	}
>  
> -	lsmblob_init(&blob, secid);
> -	ret_val = security_secid_to_secctx(&blob, &context);
> +	ret_val = security_secid_to_secctx(lsmb, &context);
>  	if (ret_val != 0)
>  		goto list_cb_failure;
>  	ret_val = nla_put(cb_arg->skb,
> @@ -1500,7 +1487,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
>  					      &iface->addr4_list);
>  		if (addr4 == NULL)
>  			goto unlabel_getattr_nolabel;
> -		secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;
> +		secattr->attr.lsmblob = netlbl_unlhsh_addr4_entry(addr4)->lsmblob;
>  		break;
>  	}
>  #if IS_ENABLED(CONFIG_IPV6)
> @@ -1513,7 +1500,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
>  					      &iface->addr6_list);
>  		if (addr6 == NULL)
>  			goto unlabel_getattr_nolabel;
> -		secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;
> +		secattr->attr.lsmblob = netlbl_unlhsh_addr6_entry(addr6)->lsmblob;
>  		break;
>  	}
>  #endif /* IPv6 */
> diff --git a/net/netlabel/netlabel_unlabeled.h b/net/netlabel/netlabel_unlabeled.h
> index 3a9e5dc9511b..dcff99695c97 100644
> --- a/net/netlabel/netlabel_unlabeled.h
> +++ b/net/netlabel/netlabel_unlabeled.h
> @@ -225,7 +225,7 @@ int netlbl_unlhsh_add(struct net *net,
>  		      const void *addr,
>  		      const void *mask,
>  		      u32 addr_len,
> -		      u32 secid,
> +		      struct lsmblob *lsmblob,
>  		      struct netlbl_audit *audit_info);
>  int netlbl_unlhsh_remove(struct net *net,
>  			 const char *dev_name,
> diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
> index b5b7c5aade8c..94787988c8fb 100644
> --- a/security/selinux/include/security.h
> +++ b/security/selinux/include/security.h
> @@ -68,6 +68,7 @@
>  struct netlbl_lsm_secattr;
>  
>  extern int selinux_enabled;
> +extern int selinux_lsmblob_slot;
>  
>  /* Policy capabilities */
>  enum {
> diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
> index c40914a157b7..320a4cdc657e 100644
> --- a/security/selinux/netlabel.c
> +++ b/security/selinux/netlabel.c
> @@ -122,7 +122,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
>  		return NULL;
>  
>  	if ((secattr->flags & NETLBL_SECATTR_SECID) &&
> -	    (secattr->attr.secid == sid))
> +	    (secattr->attr.lsmblob.secid[selinux_lsmblob_slot] == sid))
>  		return secattr;
>  
>  	return NULL;
> diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
> index e3f5d6aece66..a3be1afafd7f 100644
> --- a/security/selinux/ss/services.c
> +++ b/security/selinux/ss/services.c
> @@ -3593,7 +3593,7 @@ int security_netlbl_secattr_to_sid(struct selinux_state *state,
>  	if (secattr->flags & NETLBL_SECATTR_CACHE)
>  		*sid = *(u32 *)secattr->cache->data;
>  	else if (secattr->flags & NETLBL_SECATTR_SECID)
> -		*sid = secattr->attr.secid;
> +		*sid = secattr->attr.lsmblob.secid[selinux_lsmblob_slot];
>  	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
>  		rc = -EIDRM;
>  		ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
> @@ -3666,7 +3666,7 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state,
>  	if (secattr->domain == NULL)
>  		goto out;
>  
> -	secattr->attr.secid = sid;
> +	secattr->attr.lsmblob.secid[selinux_lsmblob_slot] = sid;
>  	secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
>  	mls_export_netlbl_lvl(policydb, ctx, secattr);
>  	rc = mls_export_netlbl_cat(policydb, ctx, secattr);
> diff --git a/security/smack/smack.h b/security/smack/smack.h
> index 7cc3a3382fee..097ffde7f202 100644
> --- a/security/smack/smack.h
> +++ b/security/smack/smack.h
> @@ -320,6 +320,7 @@ void smk_destroy_label_list(struct list_head *list);
>   * Shared data.
>   */
>  extern int smack_enabled;
> +extern int smack_lsmblob_slot;
>  extern int smack_cipso_direct;
>  extern int smack_cipso_mapped;
>  extern struct smack_known *smack_net_ambient;
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 273f311fb153..b83aba0f2013 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -3742,7 +3742,8 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
>  		/*
>  		 * Looks like a fallback, which gives us a secid.
>  		 */
> -		return smack_from_secid(sap->attr.secid);
> +		return smack_from_secid(
> +				sap->attr.lsmblob.secid[smack_lsmblob_slot]);
>  	/*
>  	 * Without guidance regarding the smack value
>  	 * for the packet fall back on the network
> diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
> index faf2ea3968b3..066d53c29ed4 100644
> --- a/security/smack/smackfs.c
> +++ b/security/smack/smackfs.c
> @@ -1150,6 +1150,7 @@ static void smk_net4addr_insert(struct smk_net4addr *new)
>  static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
>  				size_t count, loff_t *ppos)
>  {
> +	struct lsmblob lsmblob;
>  	struct smk_net4addr *snp;
>  	struct sockaddr_in newname;
>  	char *smack;
> @@ -1281,10 +1282,13 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
>  	 * this host so that incoming packets get labeled.
>  	 * but only if we didn't get the special CIPSO option
>  	 */
> -	if (rc == 0 && skp != NULL)
> +	if (rc == 0 && skp != NULL) {
> +		lsmblob_init(&lsmblob, 0);
> +		lsmblob.secid[smack_lsmblob_slot] = snp->smk_label->smk_secid;
>  		rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
> -			&snp->smk_host, &snp->smk_mask, PF_INET,
> -			snp->smk_label->smk_secid, &audit_info);
> +			&snp->smk_host, &snp->smk_mask, PF_INET, &lsmblob,
> +			&audit_info);
> +	}
>  
>  	if (rc == 0)
>  		rc = count;
> 


^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 24/24] AppArmor: Remove the exclusive flag
  2019-06-21 18:52 ` [PATCH v3 24/24] AppArmor: Remove the exclusive flag Casey Schaufler
  2019-06-22 23:15   ` Kees Cook
@ 2019-06-24 21:45   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 21:45 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> With the inclusion of the "display" process attribute
> mechanism AppArmor no longer needs to be treated as an
> "exclusive" security module. Remove the flag that indicates
> it is exclusive. Remove the stub getpeersec_dgram AppArmor
> hook as it has no effect in the single LSM case and
> interferes in the multiple LSM case.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  security/apparmor/lsm.c | 20 +-------------------
>  1 file changed, 1 insertion(+), 19 deletions(-)
> 
> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
> index dcbbefbd95ff..c4365434f10b 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -1082,22 +1082,6 @@ static int apparmor_socket_getpeersec_stream(struct socket *sock,
>  	return error;
>  }
>  
> -/**
> - * apparmor_socket_getpeersec_dgram - get security label of packet
> - * @sock: the peer socket
> - * @skb: packet data
> - * @secid: pointer to where to put the secid of the packet
> - *
> - * Sets the netlabel socket state on sk from parent
> - */
> -static int apparmor_socket_getpeersec_dgram(struct socket *sock,
> -					    struct sk_buff *skb, u32 *secid)
> -
> -{
> -	/* TODO: requires secid support */
> -	return -ENOPROTOOPT;
> -}
> -
>  /**
>   * apparmor_sock_graft - Initialize newly created socket
>   * @sk: child sock
> @@ -1196,8 +1180,6 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
>  #endif
>  	LSM_HOOK_INIT(socket_getpeersec_stream,
>  		      apparmor_socket_getpeersec_stream),
> -	LSM_HOOK_INIT(socket_getpeersec_dgram,
> -		      apparmor_socket_getpeersec_dgram),
>  	LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
>  #ifdef CONFIG_NETWORK_SECMARK
>  	LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
> @@ -1709,7 +1691,7 @@ static int __init apparmor_init(void)
>  
>  DEFINE_LSM(apparmor) = {
>  	.name = "apparmor",
> -	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
> +	.flags = LSM_FLAG_LEGACY_MAJOR,
>  	.enabled = &apparmor_enabled,
>  	.blobs = &apparmor_blob_sizes,
>  	.init = apparmor_init,
> 


^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 16/24] LSM: Ensure the correct LSM context releaser
  2019-06-21 18:52 ` [PATCH v3 16/24] LSM: Ensure the correct LSM context releaser Casey Schaufler
  2019-06-22 22:52   ` Kees Cook
@ 2019-06-24 21:46   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 21:46 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Add a new lsmcontext data structure to hold all the information
> about a "security context", including the string, its size and
> which LSM allocated the string. The allocation information is
> necessary because LSMs have different policies regarding the
> lifecycle of these strings. SELinux allocates and destroys
> them on each use, whereas Smack provides a pointer to an entry
> in a list that never goes away.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  drivers/android/binder.c                | 10 +++++--
>  fs/kernfs/dir.c                         |  9 ++++--
>  fs/kernfs/inode.c                       |  7 +++--
>  fs/nfs/nfs4proc.c                       |  8 +++--
>  fs/nfsd/nfs4xdr.c                       |  7 +++--
>  include/linux/security.h                | 39 +++++++++++++++++++++++--
>  include/net/scm.h                       |  4 ++-
>  kernel/audit.c                          | 14 ++++++---
>  kernel/auditsc.c                        | 12 ++++++--
>  net/ipv4/ip_sockglue.c                  |  4 ++-
>  net/netfilter/nf_conntrack_netlink.c    |  4 ++-
>  net/netfilter/nf_conntrack_standalone.c |  4 ++-
>  net/netfilter/nfnetlink_queue.c         | 13 ++++++---
>  net/netlabel/netlabel_unlabeled.c       | 19 +++++++++---
>  net/netlabel/netlabel_user.c            |  4 ++-
>  security/security.c                     | 12 +++++---
>  security/smack/smack_lsm.c              | 14 ++++++---
>  17 files changed, 142 insertions(+), 42 deletions(-)
> 
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 144ac4f1c24f..89e574be34cc 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -2876,6 +2876,7 @@ static void binder_transaction(struct binder_proc *proc,
>  	int t_debug_id = atomic_inc_return(&binder_last_id);
>  	char *secctx = NULL;
>  	u32 secctx_sz = 0;
> +	struct lsmcontext scaff; /* scaffolding */
>  
>  	e = binder_transaction_log_add(&binder_transaction_log);
>  	e->debug_id = t_debug_id;
> @@ -3158,7 +3159,8 @@ static void binder_transaction(struct binder_proc *proc,
>  		binder_alloc_copy_to_buffer(&target_proc->alloc,
>  					    t->buffer, buf_offset,
>  					    secctx, secctx_sz);
> -		security_release_secctx(secctx, secctx_sz);
> +		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
> +		security_release_secctx(&scaff);
>  		secctx = NULL;
>  	}
>  	t->buffer->debug_id = t->debug_id;
> @@ -3479,8 +3481,10 @@ static void binder_transaction(struct binder_proc *proc,
>  	t->buffer->transaction = NULL;
>  	binder_alloc_free_buf(&target_proc->alloc, t->buffer);
>  err_binder_alloc_buf_failed:
> -	if (secctx)
> -		security_release_secctx(secctx, secctx_sz);
> +	if (secctx) {
> +		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
> +		security_release_secctx(&scaff);
> +	}
>  err_get_secctx_failed:
>  	kfree(tcomplete);
>  	binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
> diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
> index b84d635567d3..92afad387237 100644
> --- a/fs/kernfs/dir.c
> +++ b/fs/kernfs/dir.c
> @@ -532,9 +532,12 @@ void kernfs_put(struct kernfs_node *kn)
>  	kfree_const(kn->name);
>  
>  	if (kn->iattr) {
> -		if (kn->iattr->ia_secdata)
> -			security_release_secctx(kn->iattr->ia_secdata,
> -						kn->iattr->ia_secdata_len);
> +		struct lsmcontext scaff; /* scaffolding */
> +		if (kn->iattr->ia_secdata) {
> +			lsmcontext_init(&scaff, kn->iattr->ia_secdata,
> +					kn->iattr->ia_secdata_len, 0);
> +			security_release_secctx(&scaff);
> +		}
>  		simple_xattrs_free(&kn->iattr->xattrs);
>  		kmem_cache_free(kernfs_iattrs_cache, kn->iattr);
>  	}
> diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
> index 0c1fd945ce42..02cde9dac5ee 100644
> --- a/fs/kernfs/inode.c
> +++ b/fs/kernfs/inode.c
> @@ -349,6 +349,7 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler,
>  {
>  	struct kernfs_node *kn = inode->i_private;
>  	struct kernfs_iattrs *attrs;
> +	struct lsmcontext context;
>  	void *secdata;
>  	u32 secdata_len = 0;
>  	int error;
> @@ -368,8 +369,10 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler,
>  	error = kernfs_node_setsecdata(attrs, &secdata, &secdata_len);
>  	mutex_unlock(&kernfs_mutex);
>  
> -	if (secdata)
> -		security_release_secctx(secdata, secdata_len);
> +	if (secdata) {
> +		lsmcontext_init(&context, secdata, secdata_len, 0);
> +		security_release_secctx(&context);
> +	}
>  	return error;
>  }
>  
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 4dbb0ee23432..af1c0db29c39 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -131,8 +131,12 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
>  static inline void
>  nfs4_label_release_security(struct nfs4_label *label)
>  {
> -	if (label)
> -		security_release_secctx(label->label, label->len);
> +	struct lsmcontext scaff; /* scaffolding */
> +
> +	if (label) {
> +		lsmcontext_init(&scaff, label->label, label->len, 0);
> +		security_release_secctx(&scaff);
> +	}
>  }
>  static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label)
>  {
> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index 3de42a729093..bb3db033e144 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -2420,6 +2420,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
>  	__be32 status;
>  	int err;
>  	struct nfs4_acl *acl = NULL;
> +	struct lsmcontext scaff; /* scaffolding */
>  	void *context = NULL;
>  	int contextlen;
>  	bool contextsupport = false;
> @@ -2919,8 +2920,10 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
>  
>  out:
>  #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
> -	if (context)
> -		security_release_secctx(context, contextlen);
> +	if (context) {
> +		lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/
> +		security_release_secctx(&scaff);
> +	}
>  #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
>  	kfree(acl);
>  	if (tempfh) {
> diff --git a/include/linux/security.h b/include/linux/security.h
> index c712fc72b7bd..ddf6d7cb23f1 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -76,6 +76,41 @@ enum lsm_event {
>  	LSM_POLICY_CHANGE,
>  };
>  
> +/*
> + * A "security context" is the text representation of
> + * the information used by LSMs.
> + * This structure contains the string, its length, and which LSM
> + * it is useful for.
> + */
> +struct lsmcontext {
> +	char	*context;	/* Provided by the module */
> +	u32	len;
> +	int	slot;		/* Identifies the module */
> +};
> +
> +/**
> + * lsmcontext_init - initialize an lsmcontext structure.
> + * @cp: Pointer to the context to initialize
> + * @context: Initial context, or NULL
> + * @size: Size of context, or 0
> + * @slot: Which LSM provided the context
> + *
> + * Fill in the lsmcontext from the provided information.
> + * This is a scaffolding function that will be removed when
> + * lsmcontext integration is complete.
> + */
> +static inline void lsmcontext_init(struct lsmcontext *cp, char *context,
> +				   u32 size, int slot)
> +{
> +	cp->slot = slot;
> +	cp->context = context;
> +
> +	if (context == NULL || size == 0)
> +		cp->len = 0;
> +	else
> +		cp->len = strlen(context);
> +}
> +
>  /*
>   * Data exported by the security modules
>   */
> @@ -445,7 +480,7 @@ int security_ismaclabel(const char *name);
>  int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
>  int security_secctx_to_secid(const char *secdata, u32 seclen,
>  			     struct lsmblob *blob);
> -void security_release_secctx(char *secdata, u32 seclen);
> +void security_release_secctx(struct lsmcontext *cp);
>  
>  void security_inode_invalidate_secctx(struct inode *inode);
>  int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
> @@ -1236,7 +1271,7 @@ static inline int security_secctx_to_secid(const char *secdata,
>  	return -EOPNOTSUPP;
>  }
>  
> -static inline void security_release_secctx(char *secdata, u32 seclen)
> +static inline void security_release_secctx(struct lsmcontext *cp)
>  {
>  }
>  
> diff --git a/include/net/scm.h b/include/net/scm.h
> index 31ae605fcc0a..6c7c3c229e4a 100644
> --- a/include/net/scm.h
> +++ b/include/net/scm.h
> @@ -92,6 +92,7 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
>  #ifdef CONFIG_SECURITY_NETWORK
>  static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
>  {
> +	struct lsmcontext context;
>  	char *secdata;
>  	u32 seclen;
>  	int err;
> @@ -102,7 +103,8 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
>  
>  		if (!err) {
>  			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
> -			security_release_secctx(secdata, seclen);
> +			lsmcontext_init(&context, secdata, seclen, 0);/*scaffolding*/
> +			security_release_secctx(&context);
>  		}
>  	}
>  }
> diff --git a/kernel/audit.c b/kernel/audit.c
> index 1b51e907f131..f844a2a642e6 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -1193,6 +1193,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
>  	struct audit_sig_info   *sig_data;
>  	char			*ctx = NULL;
>  	u32			len;
> +	struct lsmcontext	scaff; /* scaffolding */
>  
>  	err = audit_netlink_ok(skb, msg_type);
>  	if (err)
> @@ -1437,15 +1438,18 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
>  		}
>  		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
>  		if (!sig_data) {
> -			if (lsmblob_is_set(&audit_sig_lsm))
> -				security_release_secctx(ctx, len);
> +			if (lsmblob_is_set(&audit_sig_lsm)) {
> +				lsmcontext_init(&scaff, ctx, len, 0);
> +				security_release_secctx(&scaff);
> +			}
>  			return -ENOMEM;
>  		}
>  		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
>  		sig_data->pid = audit_sig_pid;
>  		if (lsmblob_is_set(&audit_sig_lsm)) {
>  			memcpy(sig_data->ctx, ctx, len);
> -			security_release_secctx(ctx, len);
> +			lsmcontext_init(&scaff, ctx, len, 0);
> +			security_release_secctx(&scaff);
>  		}
>  		audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
>  				 sig_data, sizeof(*sig_data) + len);
> @@ -2074,6 +2078,7 @@ int audit_log_task_context(struct audit_buffer *ab)
>  	unsigned len;
>  	int error;
>  	struct lsmblob blob;
> +	struct lsmcontext scaff; /* scaffolding */
>  
>  	security_task_getsecid(current, &blob);
>  	if (!lsmblob_is_set(&blob))
> @@ -2087,7 +2092,8 @@ int audit_log_task_context(struct audit_buffer *ab)
>  	}
>  
>  	audit_log_format(ab, " subj=%s", ctx);
> -	security_release_secctx(ctx, len);
> +	lsmcontext_init(&scaff, ctx, len, 0);
> +	security_release_secctx(&scaff);
>  	return 0;
>  
>  error_path:
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index c7aa39bda5cc..9fab0e7d90c3 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -943,6 +943,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  				 struct lsmblob *blob, char *comm)
>  {
>  	struct audit_buffer *ab;
> +	struct lsmcontext lsmcxt;
>  	char *ctx = NULL;
>  	u32 len;
>  	int rc = 0;
> @@ -960,7 +961,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  			rc = 1;
>  		} else {
>  			audit_log_format(ab, " obj=%s", ctx);
> -			security_release_secctx(ctx, len);
> +			lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/
> +			security_release_secctx(&lsmcxt);
>  		}
>  	}
>  	audit_log_format(ab, " ocomm=");
> @@ -1172,6 +1174,7 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
>  
>  static void show_special(struct audit_context *context, int *call_panic)
>  {
> +	struct lsmcontext lsmcxt;
>  	struct audit_buffer *ab;
>  	int i;
>  
> @@ -1205,7 +1208,8 @@ static void show_special(struct audit_context *context, int *call_panic)
>  				*call_panic = 1;
>  			} else {
>  				audit_log_format(ab, " obj=%s", ctx);
> -				security_release_secctx(ctx, len);
> +				lsmcontext_init(&lsmcxt, ctx, len, 0);
> +				security_release_secctx(&lsmcxt);
>  			}
>  		}
>  		if (context->ipc.has_perm) {
> @@ -1352,6 +1356,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
>  		char *ctx = NULL;
>  		u32 len;
>  		struct lsmblob blob;
> +		struct lsmcontext lsmcxt;
>  
>  		lsmblob_init(&blob, n->osid);
>  		if (security_secid_to_secctx(&blob, &ctx, &len)) {
> @@ -1360,7 +1365,8 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
>  				*call_panic = 2;
>  		} else {
>  			audit_log_format(ab, " obj=%s", ctx);
> -			security_release_secctx(ctx, len);
> +			lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */
> +			security_release_secctx(&lsmcxt);
>  		}
>  	}
>  
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index e05f4ef68bd8..7834c357b60b 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -130,6 +130,7 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
>  
>  static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
>  {
> +	struct lsmcontext context;
>  	struct lsmblob lb;
>  	char *secdata;
>  	u32 seclen;
> @@ -144,7 +145,8 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
>  		return;
>  
>  	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
> -	security_release_secctx(secdata, seclen);
> +	lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */
> +	security_release_secctx(&context);
>  }
>  
>  static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
> diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
> index ca0968f13240..6954e6600583 100644
> --- a/net/netfilter/nf_conntrack_netlink.c
> +++ b/net/netfilter/nf_conntrack_netlink.c
> @@ -331,6 +331,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
>  	int len, ret;
>  	char *secctx;
>  	struct lsmblob blob;
> +	struct lsmcontext context;
>  
>  	lsmblob_init(&blob, ct->secmark);
>  	ret = security_secid_to_secctx(&blob, &secctx, &len);
> @@ -348,7 +349,8 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
>  
>  	ret = 0;
>  nla_put_failure:
> -	security_release_secctx(secctx, len);
> +	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
> +	security_release_secctx(&context);
>  	return ret;
>  }
>  #else
> diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
> index c793103f3cd7..79158ad0486e 100644
> --- a/net/netfilter/nf_conntrack_standalone.c
> +++ b/net/netfilter/nf_conntrack_standalone.c
> @@ -176,6 +176,7 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
>  	u32 len;
>  	char *secctx;
>  	struct lsmblob blob;
> +	struct lsmcontext context;
>  
>  	lsmblob_init(&blob, ct->secmark);
>  	ret = security_secid_to_secctx(&blob, &secctx, &len);
> @@ -184,7 +185,8 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
>  
>  	seq_printf(s, "secctx=%s ", secctx);
>  
> -	security_release_secctx(secctx, len);
> +	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
> +	security_release_secctx(&context);
>  }
>  #else
>  static inline void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index 59211bff90ab..fe8403ef4e89 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -399,6 +399,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	enum ip_conntrack_info uninitialized_var(ctinfo);
>  	struct nfnl_ct_hook *nfnl_ct;
>  	bool csum_verify;
> +	struct lsmcontext scaff; /* scaffolding */
>  	char *secdata = NULL;
>  	u32 seclen = 0;
>  
> @@ -629,8 +630,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	}
>  
>  	nlh->nlmsg_len = skb->len;
> -	if (seclen)
> -		security_release_secctx(secdata, seclen);
> +	if (seclen) {
> +		lsmcontext_init(&scaff, secdata, seclen, 0);
> +		security_release_secctx(&scaff);
> +	}
>  	return skb;
>  
>  nla_put_failure:
> @@ -638,8 +641,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	kfree_skb(skb);
>  	net_err_ratelimited("nf_queue: error creating packet message\n");
>  nlmsg_failure:
> -	if (seclen)
> -		security_release_secctx(secdata, seclen);
> +	if (seclen) {
> +		lsmcontext_init(&scaff, secdata, seclen, 0);
> +		security_release_secctx(&scaff);
> +	}
>  	return NULL;
>  }
>  
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 2294aa9471e6..15b1945853be 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -387,6 +387,7 @@ int netlbl_unlhsh_add(struct net *net,
>  	struct net_device *dev;
>  	struct netlbl_unlhsh_iface *iface;
>  	struct audit_buffer *audit_buf = NULL;
> +	struct lsmcontext context;
>  	char *secctx = NULL;
>  	u32 secctx_len;
>  	struct lsmblob blob;
> @@ -457,7 +458,9 @@ int netlbl_unlhsh_add(struct net *net,
>  					     &secctx,
>  					     &secctx_len) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> -			security_release_secctx(secctx, secctx_len);
> +			/* scaffolding */
> +			lsmcontext_init(&context, secctx, secctx_len, 0);
> +			security_release_secctx(&context);
>  		}
>  		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
>  		audit_log_end(audit_buf);
> @@ -488,6 +491,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  	struct netlbl_unlhsh_addr4 *entry;
>  	struct audit_buffer *audit_buf;
>  	struct net_device *dev;
> +	struct lsmcontext context;
>  	char *secctx;
>  	u32 secctx_len;
>  	struct lsmblob blob;
> @@ -516,7 +520,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  		    security_secid_to_secctx(&blob,
>  					     &secctx, &secctx_len) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> -			security_release_secctx(secctx, secctx_len);
> +			/* scaffolding */
> +			lsmcontext_init(&context, secctx, secctx_len, 0);
> +			security_release_secctx(&context);
>  		}
>  		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
>  		audit_log_end(audit_buf);
> @@ -553,6 +559,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  	struct netlbl_unlhsh_addr6 *entry;
>  	struct audit_buffer *audit_buf;
>  	struct net_device *dev;
> +	struct lsmcontext context;
>  	char *secctx;
>  	u32 secctx_len;
>  	struct lsmblob blob;
> @@ -580,7 +587,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  		    security_secid_to_secctx(&blob,
>  					     &secctx, &secctx_len) == 0) {
>  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> -			security_release_secctx(secctx, secctx_len);
> +			lsmcontext_init(&context, secctx, secctx_len, 0);
> +			security_release_secctx(&context);
>  		}
>  		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
>  		audit_log_end(audit_buf);
> @@ -1094,6 +1102,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  	int ret_val = -ENOMEM;
>  	struct netlbl_unlhsh_walk_arg *cb_arg = arg;
>  	struct net_device *dev;
> +	struct lsmcontext context;
>  	void *data;
>  	u32 secid;
>  	char *secctx;
> @@ -1161,7 +1170,9 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  			  NLBL_UNLABEL_A_SECCTX,
>  			  secctx_len,
>  			  secctx);
> -	security_release_secctx(secctx, secctx_len);
> +	/* scaffolding */
> +	lsmcontext_init(&context, secctx, secctx_len, 0);
> +	security_release_secctx(&context);
>  	if (ret_val != 0)
>  		goto list_cb_failure;
>  
> diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
> index 2ccc6567e2a2..94aea4985b74 100644
> --- a/net/netlabel/netlabel_user.c
> +++ b/net/netlabel/netlabel_user.c
> @@ -98,6 +98,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>  					       struct netlbl_audit *audit_info)
>  {
>  	struct audit_buffer *audit_buf;
> +	struct lsmcontext context;
>  	char *secctx;
>  	u32 secctx_len;
>  	struct lsmblob blob;
> @@ -117,7 +118,8 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>  	if (audit_info->secid != 0 &&
>  	    security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
>  		audit_log_format(audit_buf, " subj=%s", secctx);
> -		security_release_secctx(secctx, secctx_len);
> +		lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/
> +		security_release_secctx(&context);
>  	}
>  
>  	return audit_buf;
> diff --git a/security/security.c b/security/security.c
> index 92c5aa427b53..d5f173e85393 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -460,6 +460,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
>  		    hooks[i].head == &security_hook_heads.setprocattr ||
>  		    hooks[i].head == &security_hook_heads.secctx_to_secid ||
>  		    hooks[i].head == &security_hook_heads.secid_to_secctx ||
> +		    hooks[i].head == &security_hook_heads.release_secctx ||
>  		    hooks[i].head == &security_hook_heads.ipc_getsecid ||
>  		    hooks[i].head == &security_hook_heads.task_getsecid ||
>  		    hooks[i].head == &security_hook_heads.inode_getsecid ||
> @@ -2091,16 +2092,19 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
>  }
>  EXPORT_SYMBOL(security_secctx_to_secid);
>  
> -void security_release_secctx(char *secdata, u32 seclen)
> +void security_release_secctx(struct lsmcontext *cp)
>  {
>  	struct security_hook_list *hp;
> -	int *display = current->security;
>  
>  	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
> -		if (*display == LSMBLOB_INVALID || *display == hp->slot) {
> -			hp->hook.release_secctx(secdata, seclen);
> +		if (cp->slot == hp->slot) {
> +			hp->hook.release_secctx(cp->context, cp->len);
> +			memset(cp, 0, sizeof(*cp));
>  			return;
>  		}
> +
> +	pr_warn("%s context \"%s\" from slot %d not released\n", __func__,
> +		cp->context, cp->slot);
>  }
>  EXPORT_SYMBOL(security_release_secctx);
>  
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index e9560b078efe..3834b751d1e9 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -4439,11 +4439,16 @@ static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
>  	return 0;
>  }
>  
> -/*
> - * There used to be a smack_release_secctx hook
> - * that did nothing back when hooks were in a vector.
> - * Now that there's a list such a hook adds cost.
> +/**
> + * smack_release_secctx - do everything necessary to free a context
> + * @secdata: Unused
> + * @seclen: Unused
> + *
> + * Do nothing but hold a slot in the hooks list.
>   */
> +static void smack_release_secctx(char *secdata, u32 seclen)
> +{
> +}
>  
>  static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
>  {
> @@ -4683,6 +4688,7 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
>  	LSM_HOOK_INIT(ismaclabel, smack_ismaclabel),
>  	LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx),
>  	LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid),
> +	LSM_HOOK_INIT(release_secctx, smack_release_secctx),
>  	LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx),
>  	LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx),
>  	LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx),
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 17/24] LSM: Use lsmcontext in security_secid_to_secctx
  2019-06-21 18:52 ` [PATCH v3 17/24] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
  2019-06-22 22:52   ` Kees Cook
@ 2019-06-24 21:46   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 21:46 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Replace the (secctx,seclen) pointer pair with a single
> lsmcontext pointer to allow return of the LSM identifier
> along with the context and context length. This allows
> security_release_secctx() to know how to release the
> context. Callers have been modified to use or save the
> returned data from the new structure.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  drivers/android/binder.c                | 24 ++++++---------
>  include/linux/security.h                |  4 +--
>  include/net/scm.h                       |  9 ++----
>  kernel/audit.c                          | 29 +++++++-----------
>  kernel/auditsc.c                        | 31 +++++++------------
>  net/ipv4/ip_sockglue.c                  |  7 ++---
>  net/netfilter/nf_conntrack_netlink.c    | 14 +++++----
>  net/netfilter/nf_conntrack_standalone.c |  7 ++---
>  net/netfilter/nfnetlink_queue.c         |  5 +++-
>  net/netlabel/netlabel_unlabeled.c       | 40 ++++++++-----------------
>  net/netlabel/netlabel_user.c            |  7 ++---
>  security/security.c                     |  9 +++---
>  12 files changed, 71 insertions(+), 115 deletions(-)
> 
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 89e574be34cc..5d417a7b9bb3 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -2874,9 +2874,7 @@ static void binder_transaction(struct binder_proc *proc,
>  	binder_size_t last_fixup_min_off = 0;
>  	struct binder_context *context = proc->context;
>  	int t_debug_id = atomic_inc_return(&binder_last_id);
> -	char *secctx = NULL;
> -	u32 secctx_sz = 0;
> -	struct lsmcontext scaff; /* scaffolding */
> +	struct lsmcontext lsmctx;
>  
>  	e = binder_transaction_log_add(&binder_transaction_log);
>  	e->debug_id = t_debug_id;
> @@ -3123,14 +3121,14 @@ static void binder_transaction(struct binder_proc *proc,
>  		struct lsmblob blob;
>  
>  		security_task_getsecid(proc->tsk, &blob);
> -		ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
> +		ret = security_secid_to_secctx(&blob, &lsmctx);
>  		if (ret) {
>  			return_error = BR_FAILED_REPLY;
>  			return_error_param = ret;
>  			return_error_line = __LINE__;
>  			goto err_get_secctx_failed;
>  		}
> -		extra_buffers_size += ALIGN(secctx_sz, sizeof(u64));
> +		extra_buffers_size += ALIGN(lsmctx.len, sizeof(u64));
>  	}
>  
>  	trace_binder_transaction(reply, t, target_node);
> @@ -3149,19 +3147,17 @@ static void binder_transaction(struct binder_proc *proc,
>  		t->buffer = NULL;
>  		goto err_binder_alloc_buf_failed;
>  	}
> -	if (secctx) {
> +	if (lsmctx.context) {
>  		size_t buf_offset = ALIGN(tr->data_size, sizeof(void *)) +
>  				    ALIGN(tr->offsets_size, sizeof(void *)) +
>  				    ALIGN(extra_buffers_size, sizeof(void *)) -
> -				    ALIGN(secctx_sz, sizeof(u64));
> +				    ALIGN(lsmctx.len, sizeof(u64));
>  
>  		t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset;
>  		binder_alloc_copy_to_buffer(&target_proc->alloc,
>  					    t->buffer, buf_offset,
> -					    secctx, secctx_sz);
> -		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
> -		security_release_secctx(&scaff);
> -		secctx = NULL;
> +					    lsmctx.context, lsmctx.len);
> +		security_release_secctx(&lsmctx);
>  	}
>  	t->buffer->debug_id = t->debug_id;
>  	t->buffer->transaction = t;
> @@ -3481,10 +3477,8 @@ static void binder_transaction(struct binder_proc *proc,
>  	t->buffer->transaction = NULL;
>  	binder_alloc_free_buf(&target_proc->alloc, t->buffer);
>  err_binder_alloc_buf_failed:
> -	if (secctx) {
> -		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
> -		security_release_secctx(&scaff);
> -	}
> +	if (lsmctx.context)
> +		security_release_secctx(&lsmctx);
>  err_get_secctx_failed:
>  	kfree(tcomplete);
>  	binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
> diff --git a/include/linux/security.h b/include/linux/security.h
> index ddf6d7cb23f1..3cbe43db16f5 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -477,7 +477,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>  			 size_t size);
>  int security_netlink_send(struct sock *sk, struct sk_buff *skb);
>  int security_ismaclabel(const char *name);
> -int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
> +int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
>  int security_secctx_to_secid(const char *secdata, u32 seclen,
>  			     struct lsmblob *blob);
>  void security_release_secctx(struct lsmcontext *cp);
> @@ -1259,7 +1259,7 @@ static inline int security_ismaclabel(const char *name)
>  }
>  
>  static inline int security_secid_to_secctx(struct lsmblob *blob,
> -					   char **secdata, u32 *seclen)
> +					   struct lsmcontext *cp)
>  {
>  	return -EOPNOTSUPP;
>  }
> diff --git a/include/net/scm.h b/include/net/scm.h
> index 6c7c3c229e4a..4a6ad8caf423 100644
> --- a/include/net/scm.h
> +++ b/include/net/scm.h
> @@ -93,17 +93,14 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
>  static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
>  {
>  	struct lsmcontext context;
> -	char *secdata;
> -	u32 seclen;
>  	int err;
>  
>  	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
> -		err = security_secid_to_secctx(&scm->lsmblob, &secdata,
> -					       &seclen);
> +		err = security_secid_to_secctx(&scm->lsmblob, &context);
>  
>  		if (!err) {
> -			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
> -			lsmcontext_init(&context, secdata, seclen, 0);/*scaffolding*/
> +			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY,
> +				 context.len, context.context);
>  			security_release_secctx(&context);
>  		}
>  	}
> diff --git a/kernel/audit.c b/kernel/audit.c
> index f844a2a642e6..436c23429319 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -1191,9 +1191,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
>  	struct audit_buffer	*ab;
>  	u16			msg_type = nlh->nlmsg_type;
>  	struct audit_sig_info   *sig_data;
> -	char			*ctx = NULL;
>  	u32			len;
> -	struct lsmcontext	scaff; /* scaffolding */
> +	struct lsmcontext	context;
>  
>  	err = audit_netlink_ok(skb, msg_type);
>  	if (err)
> @@ -1431,25 +1430,22 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
>  	case AUDIT_SIGNAL_INFO:
>  		len = 0;
>  		if (lsmblob_is_set(&audit_sig_lsm)) {
> -			err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
> -						       &len);
> +			err = security_secid_to_secctx(&audit_sig_lsm,
> +						       &context);
>  			if (err)
>  				return err;
>  		}
>  		sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
>  		if (!sig_data) {
> -			if (lsmblob_is_set(&audit_sig_lsm)) {
> -				lsmcontext_init(&scaff, ctx, len, 0);
> -				security_release_secctx(&scaff);
> -			}
> +			if (lsmblob_is_set(&audit_sig_lsm))
> +				security_release_secctx(&context);
>  			return -ENOMEM;
>  		}
>  		sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
>  		sig_data->pid = audit_sig_pid;
>  		if (lsmblob_is_set(&audit_sig_lsm)) {
> -			memcpy(sig_data->ctx, ctx, len);
> -			lsmcontext_init(&scaff, ctx, len, 0);
> -			security_release_secctx(&scaff);
> +			memcpy(sig_data->ctx, context.context, context.len);
> +			security_release_secctx(&context);
>  		}
>  		audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
>  				 sig_data, sizeof(*sig_data) + len);
> @@ -2074,26 +2070,23 @@ void audit_log_key(struct audit_buffer *ab, char *key)
>  
>  int audit_log_task_context(struct audit_buffer *ab)
>  {
> -	char *ctx = NULL;
> -	unsigned len;
>  	int error;
>  	struct lsmblob blob;
> -	struct lsmcontext scaff; /* scaffolding */
> +	struct lsmcontext context;
>  
>  	security_task_getsecid(current, &blob);
>  	if (!lsmblob_is_set(&blob))
>  		return 0;
>  
> -	error = security_secid_to_secctx(&blob, &ctx, &len);
> +	error = security_secid_to_secctx(&blob, &context);
>  	if (error) {
>  		if (error != -EINVAL)
>  			goto error_path;
>  		return 0;
>  	}
>  
> -	audit_log_format(ab, " subj=%s", ctx);
> -	lsmcontext_init(&scaff, ctx, len, 0);
> -	security_release_secctx(&scaff);
> +	audit_log_format(ab, " subj=%s", context.context);
> +	security_release_secctx(&context);
>  	return 0;
>  
>  error_path:
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 9fab0e7d90c3..0478680cd0a8 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -943,9 +943,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  				 struct lsmblob *blob, char *comm)
>  {
>  	struct audit_buffer *ab;
> -	struct lsmcontext lsmcxt;
> -	char *ctx = NULL;
> -	u32 len;
> +	struct lsmcontext lsmctx;
>  	int rc = 0;
>  
>  	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
> @@ -956,13 +954,12 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>  			 from_kuid(&init_user_ns, auid),
>  			 from_kuid(&init_user_ns, uid), sessionid);
>  	if (lsmblob_is_set(blob)) {
> -		if (security_secid_to_secctx(blob, &ctx, &len)) {
> +		if (security_secid_to_secctx(blob, &lsmctx)) {
>  			audit_log_format(ab, " obj=(none)");
>  			rc = 1;
>  		} else {
> -			audit_log_format(ab, " obj=%s", ctx);
> -			lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/
> -			security_release_secctx(&lsmcxt);
> +			audit_log_format(ab, " obj=%s", lsmctx.context);
> +			security_release_secctx(&lsmctx);
>  		}
>  	}
>  	audit_log_format(ab, " ocomm=");
> @@ -1174,7 +1171,6 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
>  
>  static void show_special(struct audit_context *context, int *call_panic)
>  {
> -	struct lsmcontext lsmcxt;
>  	struct audit_buffer *ab;
>  	int i;
>  
> @@ -1198,17 +1194,15 @@ static void show_special(struct audit_context *context, int *call_panic)
>  				 from_kgid(&init_user_ns, context->ipc.gid),
>  				 context->ipc.mode);
>  		if (osid) {
> -			char *ctx = NULL;
> -			u32 len;
> +			struct lsmcontext lsmcxt;
>  			struct lsmblob blob;
>  
>  			lsmblob_init(&blob, osid);
> -			if (security_secid_to_secctx(&blob, &ctx, &len)) {
> +			if (security_secid_to_secctx(&blob, &lsmcxt)) {
>  				audit_log_format(ab, " osid=%u", osid);
>  				*call_panic = 1;
>  			} else {
> -				audit_log_format(ab, " obj=%s", ctx);
> -				lsmcontext_init(&lsmcxt, ctx, len, 0);
> +				audit_log_format(ab, " obj=%s", lsmcxt.context);
>  				security_release_secctx(&lsmcxt);
>  			}
>  		}
> @@ -1353,20 +1347,17 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
>  				 MAJOR(n->rdev),
>  				 MINOR(n->rdev));
>  	if (n->osid != 0) {
> -		char *ctx = NULL;
> -		u32 len;
>  		struct lsmblob blob;
> -		struct lsmcontext lsmcxt;
> +		struct lsmcontext lsmctx;
>  
>  		lsmblob_init(&blob, n->osid);
> -		if (security_secid_to_secctx(&blob, &ctx, &len)) {
> +		if (security_secid_to_secctx(&blob, &lsmctx)) {
>  			audit_log_format(ab, " osid=%u", n->osid);
>  			if (call_panic)
>  				*call_panic = 2;
>  		} else {
> -			audit_log_format(ab, " obj=%s", ctx);
> -			lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */
> -			security_release_secctx(&lsmcxt);
> +			audit_log_format(ab, " obj=%s", lsmctx.context);
> +			security_release_secctx(&lsmctx);
>  		}
>  	}
>  
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index 7834c357b60b..80ae0c5a1301 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -132,20 +132,17 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
>  {
>  	struct lsmcontext context;
>  	struct lsmblob lb;
> -	char *secdata;
> -	u32 seclen;
>  	int err;
>  
>  	err = security_socket_getpeersec_dgram(NULL, skb, &lb);
>  	if (err)
>  		return;
>  
> -	err = security_secid_to_secctx(&lb, &secdata, &seclen);
> +	err = security_secid_to_secctx(&lb, &context);
>  	if (err)
>  		return;
>  
> -	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
> -	lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */
> +	put_cmsg(msg, SOL_IP, SCM_SECURITY, context.len, context.context);
>  	security_release_secctx(&context);
>  }
>  
> diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
> index 6954e6600583..403307ff0fff 100644
> --- a/net/netfilter/nf_conntrack_netlink.c
> +++ b/net/netfilter/nf_conntrack_netlink.c
> @@ -328,13 +328,12 @@ static int ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct)
>  static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
>  {
>  	struct nlattr *nest_secctx;
> -	int len, ret;
> -	char *secctx;
> +	int ret;
>  	struct lsmblob blob;
>  	struct lsmcontext context;
>  
>  	lsmblob_init(&blob, ct->secmark);
> -	ret = security_secid_to_secctx(&blob, &secctx, &len);
> +	ret = security_secid_to_secctx(&blob, &context);
>  	if (ret)
>  		return 0;
>  
> @@ -343,13 +342,12 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
>  	if (!nest_secctx)
>  		goto nla_put_failure;
>  
> -	if (nla_put_string(skb, CTA_SECCTX_NAME, secctx))
> +	if (nla_put_string(skb, CTA_SECCTX_NAME, context.context))
>  		goto nla_put_failure;
>  	nla_nest_end(skb, nest_secctx);
>  
>  	ret = 0;
>  nla_put_failure:
> -	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
>  	security_release_secctx(&context);
>  	return ret;
>  }
> @@ -620,12 +618,16 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
>  #ifdef CONFIG_NF_CONNTRACK_SECMARK
>  	int len, ret;
>  	struct lsmblob blob;
> +	struct lsmcontext context;
>  
>  	lsmblob_init(&blob, ct->secmark);
> -	ret = security_secid_to_secctx(&blob, NULL, &len);
> +	ret = security_secid_to_secctx(&blob, &context);
>  	if (ret)
>  		return 0;
>  
> +	len = context.len;
> +	security_release_secctx(&context);
> +
>  	return nla_total_size(0) /* CTA_SECCTX */
>  	       + nla_total_size(sizeof(char) * len); /* CTA_SECCTX_NAME */
>  #else
> diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
> index 79158ad0486e..fcb51ab2bb8b 100644
> --- a/net/netfilter/nf_conntrack_standalone.c
> +++ b/net/netfilter/nf_conntrack_standalone.c
> @@ -173,19 +173,16 @@ static void ct_seq_stop(struct seq_file *s, void *v)
>  static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
>  {
>  	int ret;
> -	u32 len;
> -	char *secctx;
>  	struct lsmblob blob;
>  	struct lsmcontext context;
>  
>  	lsmblob_init(&blob, ct->secmark);
> -	ret = security_secid_to_secctx(&blob, &secctx, &len);
> +	ret = security_secid_to_secctx(&blob, &context);
>  	if (ret)
>  		return;
>  
> -	seq_printf(s, "secctx=%s ", secctx);
> +	seq_printf(s, "secctx=%s ", context.context);
>  
> -	lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
>  	security_release_secctx(&context);
>  }
>  #else
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index fe8403ef4e89..6da00c7add5b 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -310,6 +310,7 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
>  	u32 seclen = 0;
>  #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
>  	struct lsmblob blob;
> +	struct lsmcontext context;
>  
>  	if (!skb || !sk_fullsock(skb->sk))
>  		return 0;
> @@ -318,10 +319,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
>  
>  	if (skb->secmark) {
>  		lsmblob_init(&blob, skb->secmark);
> -		security_secid_to_secctx(&blob, secdata, &seclen);
> +		security_secid_to_secctx(&blob, &context);
> +		*secdata = context.context;
>  	}
>  
>  	read_unlock_bh(&skb->sk->sk_callback_lock);
> +	seclen = context.len;
>  #endif
>  	return seclen;
>  }
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 15b1945853be..4716e0011ba5 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -388,8 +388,6 @@ int netlbl_unlhsh_add(struct net *net,
>  	struct netlbl_unlhsh_iface *iface;
>  	struct audit_buffer *audit_buf = NULL;
>  	struct lsmcontext context;
> -	char *secctx = NULL;
> -	u32 secctx_len;
>  	struct lsmblob blob;
>  
>  	if (addr_len != sizeof(struct in_addr) &&
> @@ -454,12 +452,9 @@ int netlbl_unlhsh_add(struct net *net,
>  	rcu_read_unlock();
>  	if (audit_buf != NULL) {
>  		lsmblob_init(&blob, secid);
> -		if (security_secid_to_secctx(&blob,
> -					     &secctx,
> -					     &secctx_len) == 0) {
> -			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> -			/* scaffolding */
> -			lsmcontext_init(&context, secctx, secctx_len, 0);
> +		if (security_secid_to_secctx(&blob, &context) == 0) {
> +			audit_log_format(audit_buf, " sec_obj=%s",
> +					 context.context);
>  			security_release_secctx(&context);
>  		}
>  		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
> @@ -492,8 +487,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  	struct audit_buffer *audit_buf;
>  	struct net_device *dev;
>  	struct lsmcontext context;
> -	char *secctx;
> -	u32 secctx_len;
>  	struct lsmblob blob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
> @@ -517,11 +510,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
>  		if (entry != NULL)
>  			lsmblob_init(&blob, entry->secid);
>  		if (entry != NULL &&
> -		    security_secid_to_secctx(&blob,
> -					     &secctx, &secctx_len) == 0) {
> -			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> -			/* scaffolding */
> -			lsmcontext_init(&context, secctx, secctx_len, 0);
> +		    security_secid_to_secctx(&blob, &context) == 0) {
> +			audit_log_format(audit_buf, " sec_obj=%s",
> +					 context.context);
>  			security_release_secctx(&context);
>  		}
>  		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
> @@ -560,8 +551,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  	struct audit_buffer *audit_buf;
>  	struct net_device *dev;
>  	struct lsmcontext context;
> -	char *secctx;
> -	u32 secctx_len;
>  	struct lsmblob blob;
>  
>  	spin_lock(&netlbl_unlhsh_lock);
> @@ -584,10 +573,9 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
>  		if (entry != NULL)
>  			lsmblob_init(&blob, entry->secid);
>  		if (entry != NULL &&
> -		    security_secid_to_secctx(&blob,
> -					     &secctx, &secctx_len) == 0) {
> -			audit_log_format(audit_buf, " sec_obj=%s", secctx);
> -			lsmcontext_init(&context, secctx, secctx_len, 0);
> +		    security_secid_to_secctx(&blob, &context) == 0) {
> +			audit_log_format(audit_buf, " sec_obj=%s",
> +					 context.context);
>  			security_release_secctx(&context);
>  		}
>  		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
> @@ -1105,8 +1093,6 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  	struct lsmcontext context;
>  	void *data;
>  	u32 secid;
> -	char *secctx;
> -	u32 secctx_len;
>  	struct lsmblob blob;
>  
>  	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
> @@ -1163,15 +1149,13 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
>  	}
>  
>  	lsmblob_init(&blob, secid);
> -	ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
> +	ret_val = security_secid_to_secctx(&blob, &context);
>  	if (ret_val != 0)
>  		goto list_cb_failure;
>  	ret_val = nla_put(cb_arg->skb,
>  			  NLBL_UNLABEL_A_SECCTX,
> -			  secctx_len,
> -			  secctx);
> -	/* scaffolding */
> -	lsmcontext_init(&context, secctx, secctx_len, 0);
> +			  context.len,
> +			  context.context);
>  	security_release_secctx(&context);
>  	if (ret_val != 0)
>  		goto list_cb_failure;
> diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
> index 94aea4985b74..2d1307f65250 100644
> --- a/net/netlabel/netlabel_user.c
> +++ b/net/netlabel/netlabel_user.c
> @@ -99,8 +99,6 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>  {
>  	struct audit_buffer *audit_buf;
>  	struct lsmcontext context;
> -	char *secctx;
> -	u32 secctx_len;
>  	struct lsmblob blob;
>  
>  	if (audit_enabled == AUDIT_OFF)
> @@ -116,9 +114,8 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>  
>  	lsmblob_init(&blob, audit_info->secid);
>  	if (audit_info->secid != 0 &&
> -	    security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
> -		audit_log_format(audit_buf, " subj=%s", secctx);
> -		lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/
> +	    security_secid_to_secctx(&blob, &context) == 0) {
> +		audit_log_format(audit_buf, " subj=%s", context.context);
>  		security_release_secctx(&context);
>  	}
>  
> diff --git a/security/security.c b/security/security.c
> index d5f173e85393..f461ab3fb9c4 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -459,7 +459,6 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
>  		    hooks[i].head == &security_hook_heads.getprocattr ||
>  		    hooks[i].head == &security_hook_heads.setprocattr ||
>  		    hooks[i].head == &security_hook_heads.secctx_to_secid ||
> -		    hooks[i].head == &security_hook_heads.secid_to_secctx ||
>  		    hooks[i].head == &security_hook_heads.release_secctx ||
>  		    hooks[i].head == &security_hook_heads.ipc_getsecid ||
>  		    hooks[i].head == &security_hook_heads.task_getsecid ||
> @@ -2064,15 +2063,17 @@ int security_ismaclabel(const char *name)
>  }
>  EXPORT_SYMBOL(security_ismaclabel);
>  
> -int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
> +int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
>  {
>  	struct security_hook_list *hp;
>  	int *display = current->security;
>  
>  	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list)
> -		if (*display == LSMBLOB_INVALID || *display == hp->slot)
> +		if (*display == LSMBLOB_INVALID || *display == hp->slot) {
> +			cp->slot = hp->slot;
>  			return hp->hook.secid_to_secctx(blob->secid[hp->slot],
> -							secdata, seclen);
> +							&cp->context, &cp->len);
> +		}
>  	return 0;
>  }
>  EXPORT_SYMBOL(security_secid_to_secctx);
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 18/24] LSM: Use lsmcontext in security_dentry_init_security
  2019-06-21 18:52 ` [PATCH v3 18/24] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
  2019-06-22 22:54   ` Kees Cook
@ 2019-06-24 21:46   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 21:46 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change the security_dentry_init_security() interface to
> fill an lsmcontext structure instead of a void * data area
> and a length. The lone caller of this interface is NFS4,
> which may make copies of the data using its own mechanisms.
> A rework of the nfs4 code to use the lsmcontext properly
> is a significant project, so the coward's way out is taken,
> and the lsmcontext data from security_dentry_init_security()
> is copied, then released directly.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

With the needed fix (below) that Kees already pointed out

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  fs/nfs/nfs4proc.c        | 26 ++++++++++++++++----------
>  include/linux/security.h |  7 +++----
>  security/security.c      | 20 ++++++++++++++++----
>  3 files changed, 35 insertions(+), 18 deletions(-)
> 
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index af1c0db29c39..952f805965bb 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -113,6 +113,7 @@ static inline struct nfs4_label *
>  nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
>  	struct iattr *sattr, struct nfs4_label *label)
>  {
> +	struct lsmcontext context;
>  	int err;
>  
>  	if (label == NULL)
> @@ -122,21 +123,26 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
>  		return NULL;
>  
>  	err = security_dentry_init_security(dentry, sattr->ia_mode,
> -				&dentry->d_name, (void **)&label->label, &label->len);
> -	if (err == 0)
> -		return label;
> +					    &dentry->d_name, &context);
> +
> +	if (err)
> +		return NULL;
> +
> +	label->label = kmemdup(context.context, context.len, GFP_KERNEL);
> +	if (label->label == NULL)
> +		label = NULL;
> +	else
> +		label->len = context.len;
> +
> +	security_release_secctx(&context);
> +
> +	return label;
>  
> -	return NULL;
>  }
>  static inline void
>  nfs4_label_release_security(struct nfs4_label *label)
>  {
> -	struct lsmcontext scaff; /* scaffolding */
> -
> -	if (label) {
> -		lsmcontext_init(&scaff, label->label, label->len, 0);
> -		security_release_secctx(&scaff);
> -	}
> +	kfree(label->label);
>  }
>  static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label)
>  {
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 3cbe43db16f5..2a2785a4e752 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -348,8 +348,8 @@ int security_sb_clone_mnt_opts(const struct super_block *oldsb,
>  int security_add_mnt_opt(const char *option, const char *val,
>  				int len, void **mnt_opts);
>  int security_dentry_init_security(struct dentry *dentry, int mode,
> -					const struct qstr *name, void **ctx,
> -					u32 *ctxlen);
> +					const struct qstr *name,
> +					struct lsmcontext *ctx);
>  int security_dentry_create_files_as(struct dentry *dentry, int mode,
>  					struct qstr *name,
>  					const struct cred *old,
> @@ -720,8 +720,7 @@ static inline void security_inode_free(struct inode *inode)
>  static inline int security_dentry_init_security(struct dentry *dentry,
>  						 int mode,
>  						 const struct qstr *name,
> -						 void **ctx,
> -						 u32 *ctxlen)
> +						 struct lsmcontext *ctx)
>  {
>  	return -EOPNOTSUPP;
>  }
> diff --git a/security/security.c b/security/security.c
> index f461ab3fb9c4..842ac65abc08 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -453,6 +453,8 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
>  		 * secid in the lsmblob structure.
>  		 */
>  		if (hooks[i].head == &security_hook_heads.audit_rule_match ||
> +		    hooks[i].head ==
> +			&security_hook_heads.dentry_init_security ||
>  		    hooks[i].head == &security_hook_heads.kernel_act_as ||
>  		    hooks[i].head ==
>  			&security_hook_heads.socket_getpeersec_dgram ||
> @@ -1040,11 +1042,21 @@ void security_inode_free(struct inode *inode)
>  }
>  
>  int security_dentry_init_security(struct dentry *dentry, int mode,
> -					const struct qstr *name, void **ctx,
> -					u32 *ctxlen)
> +				  const struct qstr *name,
> +				  struct lsmcontext *cp)
>  {
> -	return call_int_hook(dentry_init_security, -EOPNOTSUPP, dentry, mode,
> -				name, ctx, ctxlen);
> +	int *display = current->security;
> +	struct security_hook_list *hp;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.dentry_init_security,
> +			     list)
> +		if (*display == 0 || *display == hp->slot) {
> +			cp->slot = hp->slot;
> +			return hp->hook.dentry_init_security(dentry, mode,
> +					name, (void **)&cp->context, &cp->len);
> +		}
> +

should be
if (*display == LSMBLOB_INVALID || *display == hp->slot)

> +	return -EOPNOTSUPP;
>  }
>  EXPORT_SYMBOL(security_dentry_init_security);
>  
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 19/24] LSM: Use lsmcontext in security_inode_getsecctx
  2019-06-21 18:52 ` [PATCH v3 19/24] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
  2019-06-22 22:56   ` Kees Cook
@ 2019-06-24 21:46   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 21:46 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change the security_inode_getsecctx() interface to fill
> a lsmcontext structure instead of data and length pointers.
> This provides the information about which LSM created the
> context so that security_release_secctx() can use the
> correct hook. A lsmcontext is used within kernfs to store
> the security information as well.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

with the issue below fixed

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  fs/kernfs/dir.c             |  8 ++------
>  fs/kernfs/inode.c           | 34 ++++++++++++----------------------
>  fs/kernfs/kernfs-internal.h |  3 +--
>  fs/nfsd/nfs4xdr.c           | 23 +++++++++--------------
>  include/linux/security.h    |  5 +++--
>  security/security.c         | 13 +++++++++++--
>  6 files changed, 38 insertions(+), 48 deletions(-)
> 
> diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
> index 92afad387237..1d000289d8b7 100644
> --- a/fs/kernfs/dir.c
> +++ b/fs/kernfs/dir.c
> @@ -532,12 +532,8 @@ void kernfs_put(struct kernfs_node *kn)
>  	kfree_const(kn->name);
>  
>  	if (kn->iattr) {
> -		struct lsmcontext scaff; /* scaffolding */
> -		if (kn->iattr->ia_secdata) {
> -			lsmcontext_init(&scaff, kn->iattr->ia_secdata,
> -					kn->iattr->ia_secdata_len, 0);
> -			security_release_secctx(&scaff);
> -		}
> +		if (kn->iattr->ia_context.context)
> +			security_release_secctx(&kn->iattr->ia_context);
>  		simple_xattrs_free(&kn->iattr->xattrs);
>  		kmem_cache_free(kernfs_iattrs_cache, kn->iattr);
>  	}
> diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
> index 02cde9dac5ee..ffbf7863306d 100644
> --- a/fs/kernfs/inode.c
> +++ b/fs/kernfs/inode.c
> @@ -135,21 +135,14 @@ int kernfs_iop_setattr(struct dentry *dentry, struct iattr *iattr)
>  	return error;
>  }
>  
> -static int kernfs_node_setsecdata(struct kernfs_iattrs *attrs, void **secdata,
> -				  u32 *secdata_len)
> +static void kernfs_node_setsecdata(struct kernfs_iattrs *attrs,
> +				   struct lsmcontext *cp)
>  {
> -	void *old_secdata;
> -	size_t old_secdata_len;
> +	struct lsmcontext old_context;
>  
> -	old_secdata = attrs->ia_secdata;
> -	old_secdata_len = attrs->ia_secdata_len;
> -
> -	attrs->ia_secdata = *secdata;
> -	attrs->ia_secdata_len = *secdata_len;
> -
> -	*secdata = old_secdata;
> -	*secdata_len = old_secdata_len;
> -	return 0;
> +	old_context = attrs->ia_context;
> +	attrs->ia_context = *cp;
> +	*cp = old_context;
>  }
>  
>  ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size)
> @@ -192,8 +185,8 @@ static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode)
>  		 * persistent copy in kernfs_node.
>  		 */
>  		set_inode_attr(inode, &attrs->ia_iattr);
> -		security_inode_notifysecctx(inode, attrs->ia_secdata,
> -					    attrs->ia_secdata_len);
> +		security_inode_notifysecctx(inode, attrs->ia_context.context,
> +					    attrs->ia_context.len);
>  	}
>  
>  	if (kernfs_type(kn) == KERNFS_DIR)
> @@ -350,8 +343,6 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler,
>  	struct kernfs_node *kn = inode->i_private;
>  	struct kernfs_iattrs *attrs;
>  	struct lsmcontext context;
> -	void *secdata;
> -	u32 secdata_len = 0;
>  	int error;
>  
>  	attrs = kernfs_iattrs(kn);
> @@ -361,18 +352,17 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler,
>  	error = security_inode_setsecurity(inode, suffix, value, size, flags);
>  	if (error)
>  		return error;
> -	error = security_inode_getsecctx(inode, &secdata, &secdata_len);
> +	error = security_inode_getsecctx(inode, &context);
>  	if (error)
>  		return error;
>  
>  	mutex_lock(&kernfs_mutex);
> -	error = kernfs_node_setsecdata(attrs, &secdata, &secdata_len);
> +	kernfs_node_setsecdata(attrs, &context);
>  	mutex_unlock(&kernfs_mutex);
>  
> -	if (secdata) {
> -		lsmcontext_init(&context, secdata, secdata_len, 0);
> +	if (context.context)
>  		security_release_secctx(&context);
> -	}
> +
>  	return error;
>  }
>  
> diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
> index 0b7d197a904c..844a028d282f 100644
> --- a/fs/kernfs/kernfs-internal.h
> +++ b/fs/kernfs/kernfs-internal.h
> @@ -21,8 +21,7 @@
>  
>  struct kernfs_iattrs {
>  	struct iattr		ia_iattr;
> -	void			*ia_secdata;
> -	u32			ia_secdata_len;
> +	struct lsmcontext	ia_context;
>  
>  	struct simple_xattrs	xattrs;
>  };
> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index bb3db033e144..1209083565dd 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -2304,11 +2304,11 @@ nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types)
>  #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
>  static inline __be32
>  nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
> -			    void *context, int len)
> +			    struct lsmcontext *context)
>  {
>  	__be32 *p;
>  
> -	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
> +	p = xdr_reserve_space(xdr, context->len + 4 + 4 + 4);
>  	if (!p)
>  		return nfserr_resource;
>  
> @@ -2318,13 +2318,13 @@ nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
>  	 */
>  	*p++ = cpu_to_be32(0); /* lfs */
>  	*p++ = cpu_to_be32(0); /* pi */
> -	p = xdr_encode_opaque(p, context, len);
> +	p = xdr_encode_opaque(p, context->context, context->len);
>  	return 0;
>  }
>  #else
>  static inline __be32
>  nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
> -			    void *context, int len)
> +			    struct lsmcontext *context)
>  { return 0; }
>  #endif
>  
> @@ -2420,9 +2420,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
>  	__be32 status;
>  	int err;
>  	struct nfs4_acl *acl = NULL;
> -	struct lsmcontext scaff; /* scaffolding */
> -	void *context = NULL;
> -	int contextlen;
> +	struct lsmcontext context;
>  	bool contextsupport = false;
>  	struct nfsd4_compoundres *resp = rqstp->rq_resp;
>  	u32 minorversion = resp->cstate.minorversion;
> @@ -2479,7 +2477,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
>  	     bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
>  		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
>  			err = security_inode_getsecctx(d_inode(dentry),
> -						&context, &contextlen);
> +						       &context);
>  		else
>  			err = -EOPNOTSUPP;
>  		contextsupport = (err == 0);
> @@ -2908,8 +2906,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
>  	}
>  
>  	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
> -		status = nfsd4_encode_security_label(xdr, rqstp, context,
> -								contextlen);
> +		status = nfsd4_encode_security_label(xdr, rqstp, &context);
>  		if (status)
>  			goto out;
>  	}
> @@ -2920,10 +2917,8 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
>  
>  out:
>  #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
> -	if (context) {
> -		lsmcontext_init(&scaff, context, contextlen, 0); /*scaffolding*/
> -		security_release_secctx(&scaff);
> -	}
> +	if (context.context)
> +		security_release_secctx(&context);
>  #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
>  	kfree(acl);
>  	if (tempfh) {
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 2a2785a4e752..bfdb06bc5466 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -485,7 +485,7 @@ void security_release_secctx(struct lsmcontext *cp);
>  void security_inode_invalidate_secctx(struct inode *inode);
>  int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
>  int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
> -int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
> +int security_inode_getsecctx(struct inode *inode, struct lsmcontext *cp);
>  #else /* CONFIG_SECURITY */
>  
>  static inline int call_lsm_notifier(enum lsm_event event, void *data)
> @@ -1286,7 +1286,8 @@ static inline int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32
>  {
>  	return -EOPNOTSUPP;
>  }
> -static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
> +static inline int security_inode_getsecctx(struct inode *inode,
> +					   struct lsmcontext *cp)
>  {
>  	return -EOPNOTSUPP;
>  }
> diff --git a/security/security.c b/security/security.c
> index 842ac65abc08..b2ffcd1f3057 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2139,9 +2139,18 @@ int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
>  }
>  EXPORT_SYMBOL(security_inode_setsecctx);
>  
> -int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
> +int security_inode_getsecctx(struct inode *inode, struct lsmcontext *cp)
>  {
> -	return call_int_hook(inode_getsecctx, -EOPNOTSUPP, inode, ctx, ctxlen);
> +	int *display = current->security;
> +	struct security_hook_list *hp;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.inode_getsecctx, list)
> +		if (*display == 0 || *display == hp->slot) {

should be
		if (*display == LSMBLOB_INVALID || *display == hp->slot)

> +			cp->slot = hp->slot;
> +			return hp->hook.inode_getsecctx(inode,
> +					(void **)&cp->context, &cp->len);
> +		}
> +	return -EOPNOTSUPP;
>  }
>  EXPORT_SYMBOL(security_inode_getsecctx);
>  
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 20/24] LSM: security_secid_to_secctx in netlink netfilter
  2019-06-21 18:52 ` [PATCH v3 20/24] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
  2019-06-22 22:57   ` Kees Cook
@ 2019-06-24 21:47   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 21:47 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change netlink netfilter interfaces to use lsmcontext
> pointers, and remove scaffolding.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>

> ---
>  net/netfilter/nfnetlink_queue.c | 32 +++++++++++++-------------------
>  1 file changed, 13 insertions(+), 19 deletions(-)
> 
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index 6da00c7add5b..69efb688383f 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -305,12 +305,10 @@ static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
>  	return -1;
>  }
>  
> -static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
> +static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context)
>  {
> -	u32 seclen = 0;
>  #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
>  	struct lsmblob blob;
> -	struct lsmcontext context;
>  
>  	if (!skb || !sk_fullsock(skb->sk))
>  		return 0;
> @@ -318,15 +316,16 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
>  	read_lock_bh(&skb->sk->sk_callback_lock);
>  
>  	if (skb->secmark) {
> +		/* Any LSM might be looking for the secmark */
>  		lsmblob_init(&blob, skb->secmark);
> -		security_secid_to_secctx(&blob, &context);
> -		*secdata = context.context;
> +		security_secid_to_secctx(&blob, context);
>  	}
>  
>  	read_unlock_bh(&skb->sk->sk_callback_lock);
> -	seclen = context.len;
> +	return context->len;
> +#else
> +	return 0;
>  #endif
> -	return seclen;
>  }
>  
>  static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
> @@ -402,8 +401,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	enum ip_conntrack_info uninitialized_var(ctinfo);
>  	struct nfnl_ct_hook *nfnl_ct;
>  	bool csum_verify;
> -	struct lsmcontext scaff; /* scaffolding */
> -	char *secdata = NULL;
> +	struct lsmcontext context;
>  	u32 seclen = 0;
>  
>  	size =    nlmsg_total_size(sizeof(struct nfgenmsg))
> @@ -470,7 +468,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	}
>  
>  	if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
> -		seclen = nfqnl_get_sk_secctx(entskb, &secdata);
> +		seclen = nfqnl_get_sk_secctx(entskb, &context);
>  		if (seclen)
>  			size += nla_total_size(seclen);
>  	}
> @@ -605,7 +603,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	    nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
>  		goto nla_put_failure;
>  
> -	if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
> +	if (seclen && nla_put(skb, NFQA_SECCTX, context.len, context.context))
>  		goto nla_put_failure;
>  
>  	if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
> @@ -633,10 +631,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	}
>  
>  	nlh->nlmsg_len = skb->len;
> -	if (seclen) {
> -		lsmcontext_init(&scaff, secdata, seclen, 0);
> -		security_release_secctx(&scaff);
> -	}
> +	if (seclen)
> +		security_release_secctx(&context);
>  	return skb;
>  
>  nla_put_failure:
> @@ -644,10 +640,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	kfree_skb(skb);
>  	net_err_ratelimited("nf_queue: error creating packet message\n");
>  nlmsg_failure:
> -	if (seclen) {
> -		lsmcontext_init(&scaff, secdata, seclen, 0);
> -		security_release_secctx(&scaff);
> -	}
> +	if (seclen)
> +		security_release_secctx(&context);
>  	return NULL;
>  }
>  
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* [PATCH v3 22/24] LSM: Return the lsmblob slot on initialization
  2019-06-21 18:52 ` [PATCH v3 22/24] LSM: Return the lsmblob slot on initialization Casey Schaufler
  2019-06-22 23:13   ` Kees Cook
@ 2019-06-24 21:47   ` John Johansen
  1 sibling, 0 replies; 81+ messages in thread
From: John Johansen @ 2019-06-24 21:47 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, penguin-kernel, paul, sds

On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Return the slot allocated to the calling LSM in the lsmblob
> structure. This can be used to set lsmblobs explicitly for
> netlabel interfaces.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: John Johansen <john.johansen@canonical.com>


> ---
>  include/linux/lsm_hooks.h  | 4 ++--
>  security/apparmor/lsm.c    | 8 ++++++--
>  security/security.c        | 9 +++++++--
>  security/selinux/hooks.c   | 5 ++++-
>  security/smack/smack_lsm.c | 5 ++++-
>  5 files changed, 23 insertions(+), 8 deletions(-)
> 
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index 4d1ddf1a2aa6..ce341bcbce5d 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -2068,8 +2068,8 @@ struct lsm_blob_sizes {
>  extern struct security_hook_heads security_hook_heads;
>  extern char *lsm_names;
>  
> -extern void security_add_hooks(struct security_hook_list *hooks, int count,
> -				char *lsm);
> +extern int security_add_hooks(struct security_hook_list *hooks, int count,
> +			      char *lsm);
>  
>  #define LSM_FLAG_LEGACY_MAJOR	BIT(0)
>  #define LSM_FLAG_EXCLUSIVE	BIT(1)
> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
> index 2716e7731279..dcbbefbd95ff 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -47,6 +47,9 @@
>  /* Flag indicating whether initialization completed */
>  int apparmor_initialized;
>  
> +/* Slot for the AppArmor secid in the lsmblob structure */
> +int apparmor_lsmblob_slot;
> +
>  DEFINE_PER_CPU(struct aa_buffers, aa_buffers);
>  
>  
> @@ -1678,8 +1681,9 @@ static int __init apparmor_init(void)
>  		aa_free_root_ns();
>  		goto buffers_out;
>  	}
> -	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
> -				"apparmor");
> +	apparmor_lsmblob_slot = security_add_hooks(apparmor_hooks,
> +						   ARRAY_SIZE(apparmor_hooks),
> +						   "apparmor");
>  
>  	/* Report that AppArmor successfully initialized */
>  	apparmor_initialized = 1;
> diff --git a/security/security.c b/security/security.c
> index b2ffcd1f3057..c93a368b697b 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -437,9 +437,12 @@ static int lsm_slot __initdata;
>   * Each LSM has to register its hooks with the infrastructure.
>   * If the LSM is using hooks that export secids allocate a slot
>   * for it in the lsmblob.
> + *
> + * Returns the slot number in the lsmblob structure if one is
> + * allocated or LSMBLOB_INVALID if one was not allocated.
>   */
> -void __init security_add_hooks(struct security_hook_list *hooks, int count,
> -				char *lsm)
> +int __init security_add_hooks(struct security_hook_list *hooks, int count,
> +			      char *lsm)
>  {
>  	int slot = LSMBLOB_INVALID;
>  	int i;
> @@ -479,6 +482,8 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
>  	}
>  	if (lsm_append(lsm, &lsm_names) < 0)
>  		panic("%s - Cannot get early memory.\n", __func__);
> +
> +	return slot;
>  }
>  
>  int call_lsm_notifier(enum lsm_event event, void *data)
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index ee840fecfebb..1e09acbf9630 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -103,6 +103,7 @@
>  #include "avc_ss.h"
>  
>  struct selinux_state selinux_state;
> +int selinux_lsmblob_slot;
>  
>  /* SECMARK reference count */
>  static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
> @@ -6877,7 +6878,9 @@ static __init int selinux_init(void)
>  
>  	hashtab_cache_init();
>  
> -	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
> +	selinux_lsmblob_slot = security_add_hooks(selinux_hooks,
> +						  ARRAY_SIZE(selinux_hooks),
> +						  "selinux");
>  
>  	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
>  		panic("SELinux: Unable to register AVC netcache callback\n");
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 3834b751d1e9..273f311fb153 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -60,6 +60,7 @@ static LIST_HEAD(smk_ipv6_port_list);
>  #endif
>  static struct kmem_cache *smack_inode_cache;
>  int smack_enabled;
> +int smack_lsmblob_slot;
>  
>  #define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
>  static struct {
> @@ -4749,7 +4750,9 @@ static __init int smack_init(void)
>  	/*
>  	 * Register with LSM
>  	 */
> -	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
> +	smack_lsmblob_slot = security_add_hooks(smack_hooks,
> +						ARRAY_SIZE(smack_hooks),
> +						"smack");
>  	smack_enabled = 1;
>  
>  	pr_info("Smack:  Initializing.\n");
> 




^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 22/24] LSM: Return the lsmblob slot on initialization
  2019-06-24 21:39     ` John Johansen
@ 2019-06-24 21:50       ` Kees Cook
  2019-06-24 21:53       ` Casey Schaufler
  1 sibling, 0 replies; 81+ messages in thread
From: Kees Cook @ 2019-06-24 21:50 UTC (permalink / raw)
  To: John Johansen
  Cc: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux, penguin-kernel, paul, sds

On Mon, Jun 24, 2019 at 02:39:23PM -0700, John Johansen wrote:
> On 6/22/19 4:13 PM, Kees Cook wrote:
> > On Fri, Jun 21, 2019 at 11:52:31AM -0700, Casey Schaufler wrote:
> >> Return the slot allocated to the calling LSM in the lsmblob
> >> structure. This can be used to set lsmblobs explicitly for
> >> netlabel interfaces.
> >>
> >> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> > 
> > Reviewed-by: Kees Cook <keescook@chromium.org>
> > 
> > (I have some thoughts on refactoring the slot assignment, but that
> > should happen after this series -- it's nothing more than a storage
> > optimization.)
> > 
> > -Kees
> 
> haha so do I, now I am curious as to how close they align

My plan is to create a __ro_after_init "LSM State" structure to hold
various things that are needed after init time. All of the lsm_info
structures are __initdata, so they can't be retained after init
(currently). As far as I can see, there are already a few things that
are retained after init:

LSM name (currently a pointer in every hook)
enabled state (technically optional, currently known internally to each LSM)
blob size details (currently known internally to each LSM)

and now we'll be adding the "slot". So I was thinking something like:

struct lsm_state {
	const char *name;
	int enabled;
	struct blob_sizes lbs;
	int slot;
};

And then change the hooks to each carry a pointer to the lsm_state
(instead of a name pointer). Also I think it'd be cleanest to define
and export the lsm_state instance it via the DEFINE_LSM macro, possibly
instead of the existing blob_size pointer. It's possible that lsm_info
should just gain some fields and no longer be __initdata, too. We'll
see!

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 22/24] LSM: Return the lsmblob slot on initialization
  2019-06-24 21:39     ` John Johansen
  2019-06-24 21:50       ` Kees Cook
@ 2019-06-24 21:53       ` Casey Schaufler
  1 sibling, 0 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-24 21:53 UTC (permalink / raw)
  To: John Johansen, Kees Cook
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	penguin-kernel, paul, sds

On 6/24/2019 2:39 PM, John Johansen wrote:
> On 6/22/19 4:13 PM, Kees Cook wrote:
>> On Fri, Jun 21, 2019 at 11:52:31AM -0700, Casey Schaufler wrote:
>>> Return the slot allocated to the calling LSM in the lsmblob
>>> structure. This can be used to set lsmblobs explicitly for
>>> netlabel interfaces.
>>>
>>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>> Reviewed-by: Kees Cook <keescook@chromium.org>
>>
>> (I have some thoughts on refactoring the slot assignment, but that
>> should happen after this series -- it's nothing more than a storage
>> optimization.)
>>
>> -Kees
> haha so do I, now I am curious as to how close they align

Plan A: Each LSM has a lsm_id {.name, .slot}, the address of which
is passed to security_add_hooks() in place of the current char *lsm.
This is added to each hook instead of the *lsm. The slot value is
set if the LSM requests one. One slot integer per LSM instead of one
per hook.

>
>
>>> ---
>>>  include/linux/lsm_hooks.h  | 4 ++--
>>>  security/apparmor/lsm.c    | 8 ++++++--
>>>  security/security.c        | 9 +++++++--
>>>  security/selinux/hooks.c   | 5 ++++-
>>>  security/smack/smack_lsm.c | 5 ++++-
>>>  5 files changed, 23 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
>>> index 4d1ddf1a2aa6..ce341bcbce5d 100644
>>> --- a/include/linux/lsm_hooks.h
>>> +++ b/include/linux/lsm_hooks.h
>>> @@ -2068,8 +2068,8 @@ struct lsm_blob_sizes {
>>>  extern struct security_hook_heads security_hook_heads;
>>>  extern char *lsm_names;
>>>  
>>> -extern void security_add_hooks(struct security_hook_list *hooks, int count,
>>> -				char *lsm);
>>> +extern int security_add_hooks(struct security_hook_list *hooks, int count,
>>> +			      char *lsm);
>>>  
>>>  #define LSM_FLAG_LEGACY_MAJOR	BIT(0)
>>>  #define LSM_FLAG_EXCLUSIVE	BIT(1)
>>> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
>>> index 2716e7731279..dcbbefbd95ff 100644
>>> --- a/security/apparmor/lsm.c
>>> +++ b/security/apparmor/lsm.c
>>> @@ -47,6 +47,9 @@
>>>  /* Flag indicating whether initialization completed */
>>>  int apparmor_initialized;
>>>  
>>> +/* Slot for the AppArmor secid in the lsmblob structure */
>>> +int apparmor_lsmblob_slot;
>>> +
>>>  DEFINE_PER_CPU(struct aa_buffers, aa_buffers);
>>>  
>>>  
>>> @@ -1678,8 +1681,9 @@ static int __init apparmor_init(void)
>>>  		aa_free_root_ns();
>>>  		goto buffers_out;
>>>  	}
>>> -	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
>>> -				"apparmor");
>>> +	apparmor_lsmblob_slot = security_add_hooks(apparmor_hooks,
>>> +						   ARRAY_SIZE(apparmor_hooks),
>>> +						   "apparmor");
>>>  
>>>  	/* Report that AppArmor successfully initialized */
>>>  	apparmor_initialized = 1;
>>> diff --git a/security/security.c b/security/security.c
>>> index b2ffcd1f3057..c93a368b697b 100644
>>> --- a/security/security.c
>>> +++ b/security/security.c
>>> @@ -437,9 +437,12 @@ static int lsm_slot __initdata;
>>>   * Each LSM has to register its hooks with the infrastructure.
>>>   * If the LSM is using hooks that export secids allocate a slot
>>>   * for it in the lsmblob.
>>> + *
>>> + * Returns the slot number in the lsmblob structure if one is
>>> + * allocated or LSMBLOB_INVALID if one was not allocated.
>>>   */
>>> -void __init security_add_hooks(struct security_hook_list *hooks, int count,
>>> -				char *lsm)
>>> +int __init security_add_hooks(struct security_hook_list *hooks, int count,
>>> +			      char *lsm)
>>>  {
>>>  	int slot = LSMBLOB_INVALID;
>>>  	int i;
>>> @@ -479,6 +482,8 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
>>>  	}
>>>  	if (lsm_append(lsm, &lsm_names) < 0)
>>>  		panic("%s - Cannot get early memory.\n", __func__);
>>> +
>>> +	return slot;
>>>  }
>>>  
>>>  int call_lsm_notifier(enum lsm_event event, void *data)
>>> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
>>> index ee840fecfebb..1e09acbf9630 100644
>>> --- a/security/selinux/hooks.c
>>> +++ b/security/selinux/hooks.c
>>> @@ -103,6 +103,7 @@
>>>  #include "avc_ss.h"
>>>  
>>>  struct selinux_state selinux_state;
>>> +int selinux_lsmblob_slot;
>>>  
>>>  /* SECMARK reference count */
>>>  static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
>>> @@ -6877,7 +6878,9 @@ static __init int selinux_init(void)
>>>  
>>>  	hashtab_cache_init();
>>>  
>>> -	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
>>> +	selinux_lsmblob_slot = security_add_hooks(selinux_hooks,
>>> +						  ARRAY_SIZE(selinux_hooks),
>>> +						  "selinux");
>>>  
>>>  	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
>>>  		panic("SELinux: Unable to register AVC netcache callback\n");
>>> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
>>> index 3834b751d1e9..273f311fb153 100644
>>> --- a/security/smack/smack_lsm.c
>>> +++ b/security/smack/smack_lsm.c
>>> @@ -60,6 +60,7 @@ static LIST_HEAD(smk_ipv6_port_list);
>>>  #endif
>>>  static struct kmem_cache *smack_inode_cache;
>>>  int smack_enabled;
>>> +int smack_lsmblob_slot;
>>>  
>>>  #define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
>>>  static struct {
>>> @@ -4749,7 +4750,9 @@ static __init int smack_init(void)
>>>  	/*
>>>  	 * Register with LSM
>>>  	 */
>>> -	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
>>> +	smack_lsmblob_slot = security_add_hooks(smack_hooks,
>>> +						ARRAY_SIZE(smack_hooks),
>>> +						"smack");
>>>  	smack_enabled = 1;
>>>  
>>>  	pr_info("Smack:  Initializing.\n");
>>> -- 
>>> 2.20.1
>>>

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob
  2019-06-24 21:33   ` John Johansen
@ 2019-06-25  1:01     ` Casey Schaufler
  2019-06-25  1:46       ` Paul Moore
  0 siblings, 1 reply; 81+ messages in thread
From: Casey Schaufler @ 2019-06-25  1:01 UTC (permalink / raw)
  To: John Johansen, casey.schaufler, jmorris, linux-security-module, selinux
  Cc: keescook, penguin-kernel, paul, sds, Eric Paris, casey

On 6/24/2019 2:33 PM, John Johansen wrote:
> On 6/21/19 11:52 AM, Casey Schaufler wrote:
>> Change the audit code to store full lsmblob data instead of
>> a single u32 secid. This allows for multiple security modules
>> to use the audit system at the same time. It also allows the
>> removal of scaffolding code that was included during the
>> revision of LSM interfaces.
>>
>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> I know Kees raised this too, but I haven't seen a reply
>
> Eric (Paul is already CCed): I have directly added you because of
> the question below.
>
> In summary there isn't necessarily a single secid any more, and
> we need to know whether dropping the logging of the secid or
> logging all secids is the correct action.

It is to be considered that this is an error case. If
everything is working normally you should have produced
a secctx previously, which you'll have included in the
audit record. Including the secid in the record ought to
be pointless, as the secid is strictly an internal token
with no meaning outside the running kernel. You are providing
no security relevant information by providing the secid.
I will grant the possibility that the secid might be useful
in debugging, but for that a pr_warn is more appropriate
than a field in the audit record.

>
>> ---
>>  kernel/audit.h   |  6 +++---
>>  kernel/auditsc.c | 38 +++++++++++---------------------------
>>  2 files changed, 14 insertions(+), 30 deletions(-)
>>
>> diff --git a/kernel/audit.h b/kernel/audit.h
>> index 29e29c6f4afb..a8dd479e9556 100644
>> --- a/kernel/audit.h
>> +++ b/kernel/audit.h
>> @@ -91,7 +91,7 @@ struct audit_names {
>>  	kuid_t			uid;
>>  	kgid_t			gid;
>>  	dev_t			rdev;
>> -	u32			osid;
>> +	struct lsmblob		olsm;
>>  	struct audit_cap_data	fcap;
>>  	unsigned int		fcap_ver;
>>  	unsigned char		type;		/* record type */
>> @@ -148,7 +148,7 @@ struct audit_context {
>>  	kuid_t		    target_auid;
>>  	kuid_t		    target_uid;
>>  	unsigned int	    target_sessionid;
>> -	struct lsmblob   target_lsm;
>> +	struct lsmblob	    target_lsm;
>>  	char		    target_comm[TASK_COMM_LEN];
>>  
>>  	struct audit_tree_refs *trees, *first_trees;
>> @@ -165,7 +165,7 @@ struct audit_context {
>>  			kuid_t			uid;
>>  			kgid_t			gid;
>>  			umode_t			mode;
>> -			u32			osid;
>> +			struct lsmblob		olsm;
>>  			int			has_perm;
>>  			uid_t			perm_uid;
>>  			gid_t			perm_gid;
>> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
>> index 0478680cd0a8..d3ad13f11788 100644
>> --- a/kernel/auditsc.c
>> +++ b/kernel/auditsc.c
>> @@ -646,17 +646,15 @@ static int audit_filter_rules(struct task_struct *tsk,
>>  			if (f->lsm_rule) {
>>  				/* Find files that match */
>>  				if (name) {
>> -					lsmblob_init(&blob, name->osid);
>>  					result = security_audit_rule_match(
>> -								&blob,
>> +								&name->olsm,
>>  								f->type,
>>  								f->op,
>>  								f->lsm_rule);
>>  				} else if (ctx) {
>>  					list_for_each_entry(n, &ctx->names_list, list) {
>> -						lsmblob_init(&blob, n->osid);
>>  						if (security_audit_rule_match(
>> -								&blob,
>> +								&n->olsm,
>>  								f->type,
>>  								f->op,
>>  								f->lsm_rule)) {
>> @@ -668,8 +666,7 @@ static int audit_filter_rules(struct task_struct *tsk,
>>  				/* Find ipc objects that match */
>>  				if (!ctx || ctx->type != AUDIT_IPC)
>>  					break;
>> -				lsmblob_init(&blob, ctx->ipc.osid);
>> -				if (security_audit_rule_match(&blob,
>> +				if (security_audit_rule_match(&ctx->ipc.olsm,
>>  							      f->type, f->op,
>>  							      f->lsm_rule))
>>  					++result;
>> @@ -1187,21 +1184,18 @@ static void show_special(struct audit_context *context, int *call_panic)
>>  				context->socketcall.args[i]);
>>  		break; }
>>  	case AUDIT_IPC: {
>> -		u32 osid = context->ipc.osid;
>> +		struct lsmblob *olsm = &context->ipc.olsm;
>>  
>>  		audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
>>  				 from_kuid(&init_user_ns, context->ipc.uid),
>>  				 from_kgid(&init_user_ns, context->ipc.gid),
>>  				 context->ipc.mode);
>> -		if (osid) {
>> +		if (lsmblob_is_set(olsm)) {
>>  			struct lsmcontext lsmcxt;
>> -			struct lsmblob blob;
>>  
>> -			lsmblob_init(&blob, osid);
>> -			if (security_secid_to_secctx(&blob, &lsmcxt)) {
>> -				audit_log_format(ab, " osid=%u", osid);
> I am not comfortable just dropping this I would think logging all secids is the
> correct action here.
>
>
>> +			if (security_secid_to_secctx(olsm, &lsmcxt))
>>  				*call_panic = 1;
>> -			} else {
>> +			else {
>>  				audit_log_format(ab, " obj=%s", lsmcxt.context);
>>  				security_release_secctx(&lsmcxt);
>>  			}
>> @@ -1346,13 +1340,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
>>  				 from_kgid(&init_user_ns, n->gid),
>>  				 MAJOR(n->rdev),
>>  				 MINOR(n->rdev));
>> -	if (n->osid != 0) {
>> -		struct lsmblob blob;
>> +	if (lsmblob_is_set(&n->olsm)) {
>>  		struct lsmcontext lsmctx;
>>  
>> -		lsmblob_init(&blob, n->osid);
>> -		if (security_secid_to_secctx(&blob, &lsmctx)) {
>> -			audit_log_format(ab, " osid=%u", n->osid);
> and here
>
>
>> +		if (security_secid_to_secctx(&n->olsm, &lsmctx)) {
>>  			if (call_panic)
>>  				*call_panic = 2;
>>  		} else {
>> @@ -1906,17 +1897,13 @@ static inline int audit_copy_fcaps(struct audit_names *name,
>>  void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
>>  		      struct inode *inode, unsigned int flags)
>>  {
>> -	struct lsmblob blob;
>> -
>>  	name->ino   = inode->i_ino;
>>  	name->dev   = inode->i_sb->s_dev;
>>  	name->mode  = inode->i_mode;
>>  	name->uid   = inode->i_uid;
>>  	name->gid   = inode->i_gid;
>>  	name->rdev  = inode->i_rdev;
>> -	security_inode_getsecid(inode, &blob);
>> -	/* scaffolding until osid is updated */
>> -	name->osid = blob.secid[0];
>> +	security_inode_getsecid(inode, &name->olsm);
>>  	if (flags & AUDIT_INODE_NOEVAL) {
>>  		name->fcap_ver = -1;
>>  		return;
>> @@ -2266,14 +2253,11 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
>>  void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
>>  {
>>  	struct audit_context *context = audit_context();
>> -	struct lsmblob blob;
>>  	context->ipc.uid = ipcp->uid;
>>  	context->ipc.gid = ipcp->gid;
>>  	context->ipc.mode = ipcp->mode;
>>  	context->ipc.has_perm = 0;
>> -	security_ipc_getsecid(ipcp, &blob);
>> -	/* scaffolding on the [0] - change "osid" to a lsmblob */
>> -	context->ipc.osid = blob.secid[0];
>> +	security_ipc_getsecid(ipcp, &context->ipc.olsm);
>>  	context->type = AUDIT_IPC;
>>  }
>>  
>>


^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob
  2019-06-25  1:01     ` Casey Schaufler
@ 2019-06-25  1:46       ` Paul Moore
  2019-06-25  2:14         ` John Johansen
  0 siblings, 1 reply; 81+ messages in thread
From: Paul Moore @ 2019-06-25  1:46 UTC (permalink / raw)
  To: Casey Schaufler
  Cc: John Johansen, casey.schaufler, James Morris,
	linux-security-module, selinux, keescook, penguin-kernel,
	Stephen Smalley, Eric Paris, linux-audit

On Mon, Jun 24, 2019 at 9:01 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> On 6/24/2019 2:33 PM, John Johansen wrote:
> > On 6/21/19 11:52 AM, Casey Schaufler wrote:
> >> Change the audit code to store full lsmblob data instead of
> >> a single u32 secid. This allows for multiple security modules
> >> to use the audit system at the same time. It also allows the
> >> removal of scaffolding code that was included during the
> >> revision of LSM interfaces.
> >>
> >> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> > I know Kees raised this too, but I haven't seen a reply
> >
> > Eric (Paul is already CCed): I have directly added you because of
> > the question below.
> >
> > In summary there isn't necessarily a single secid any more, and
> > we need to know whether dropping the logging of the secid or
> > logging all secids is the correct action.
>
> It is to be considered that this is an error case. If
> everything is working normally you should have produced
> a secctx previously, which you'll have included in the
> audit record. Including the secid in the record ought to
> be pointless, as the secid is strictly an internal token
> with no meaning outside the running kernel. You are providing
> no security relevant information by providing the secid.
> I will grant the possibility that the secid might be useful
> in debugging, but for that a pr_warn is more appropriate
> than a field in the audit record.

FWIW, this probably should have been CC'd to the audit list.

I agree that this is an error case (security_secid_to_secctx() failed
to resolve the secid) and further that logging the secid, or a
collection of secids, has little value the way things currently work.
Since secids are a private kernel implementation detail, we don't
really display them outside the context of the kernel, including in
the audit logs.  Recording a secid in this case doesn't provide
anything meaningful since secids aren't recorded in the audit record
stream, only the secctxs, and there is no "magic decoder ring" to go
between the two in the audit logs, or anywhere else in userspace for
that matter.

> >> ---
> >>  kernel/audit.h   |  6 +++---
> >>  kernel/auditsc.c | 38 +++++++++++---------------------------
> >>  2 files changed, 14 insertions(+), 30 deletions(-)

...

> >> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> >> index 0478680cd0a8..d3ad13f11788 100644
> >> --- a/kernel/auditsc.c
> >> +++ b/kernel/auditsc.c
> >> @@ -1187,21 +1184,18 @@ static void show_special(struct audit_context *context, int *call_panic)
> >>                              context->socketcall.args[i]);
> >>              break; }
> >>      case AUDIT_IPC: {
> >> -            u32 osid = context->ipc.osid;
> >> +            struct lsmblob *olsm = &context->ipc.olsm;
> >>
> >>              audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
> >>                               from_kuid(&init_user_ns, context->ipc.uid),
> >>                               from_kgid(&init_user_ns, context->ipc.gid),
> >>                               context->ipc.mode);
> >> -            if (osid) {
> >> +            if (lsmblob_is_set(olsm)) {
> >>                      struct lsmcontext lsmcxt;
> >> -                    struct lsmblob blob;
> >>
> >> -                    lsmblob_init(&blob, osid);
> >> -                    if (security_secid_to_secctx(&blob, &lsmcxt)) {
> >> -                            audit_log_format(ab, " osid=%u", osid);
> > I am not comfortable just dropping this I would think logging all secids is the
> > correct action here.
> >
> >
> >> +                    if (security_secid_to_secctx(olsm, &lsmcxt))
> >>                              *call_panic = 1;
> >> -                    } else {
> >> +                    else {
> >>                              audit_log_format(ab, " obj=%s", lsmcxt.context);
> >>                              security_release_secctx(&lsmcxt);
> >>                      }

-- 
paul moore
www.paul-moore.com

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob
  2019-06-25  1:46       ` Paul Moore
@ 2019-06-25  2:14         ` John Johansen
  2019-06-25  2:42           ` Paul Moore
  0 siblings, 1 reply; 81+ messages in thread
From: John Johansen @ 2019-06-25  2:14 UTC (permalink / raw)
  To: Paul Moore, Casey Schaufler
  Cc: casey.schaufler, James Morris, linux-security-module, selinux,
	keescook, penguin-kernel, Stephen Smalley, Eric Paris,
	linux-audit

On 6/24/19 6:46 PM, Paul Moore wrote:
> On Mon, Jun 24, 2019 at 9:01 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
>> On 6/24/2019 2:33 PM, John Johansen wrote:
>>> On 6/21/19 11:52 AM, Casey Schaufler wrote:
>>>> Change the audit code to store full lsmblob data instead of
>>>> a single u32 secid. This allows for multiple security modules
>>>> to use the audit system at the same time. It also allows the
>>>> removal of scaffolding code that was included during the
>>>> revision of LSM interfaces.
>>>>
>>>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>>> I know Kees raised this too, but I haven't seen a reply
>>>
>>> Eric (Paul is already CCed): I have directly added you because of
>>> the question below.
>>>
>>> In summary there isn't necessarily a single secid any more, and
>>> we need to know whether dropping the logging of the secid or
>>> logging all secids is the correct action.
>>
>> It is to be considered that this is an error case. If
>> everything is working normally you should have produced
>> a secctx previously, which you'll have included in the
>> audit record. Including the secid in the record ought to
>> be pointless, as the secid is strictly an internal token
>> with no meaning outside the running kernel. You are providing
>> no security relevant information by providing the secid.
>> I will grant the possibility that the secid might be useful
>> in debugging, but for that a pr_warn is more appropriate
>> than a field in the audit record.
> 
> FWIW, this probably should have been CC'd to the audit list.
> 
hrmm indeed, sorry

> I agree that this is an error case (security_secid_to_secctx() failed
> to resolve the secid) and further that logging the secid, or a
> collection of secids, has little value the way things currently work.
> Since secids are a private kernel implementation detail, we don't
> really display them outside the context of the kernel, including in
> the audit logs.  Recording a secid in this case doesn't provide
> anything meaningful since secids aren't recorded in the audit record
> stream, only the secctxs, and there is no "magic decoder ring" to go
> between the two in the audit logs, or anywhere else in userspace for
> that matter.
> 
Okay, thanks. Casey I am good with just a pr_warn here. I just didn't
have context of why it was going to the audit_log and didn't want
to change that without some more input.


>>>> ---
>>>>  kernel/audit.h   |  6 +++---
>>>>  kernel/auditsc.c | 38 +++++++++++---------------------------
>>>>  2 files changed, 14 insertions(+), 30 deletions(-)
> 
> ...
> 
>>>> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
>>>> index 0478680cd0a8..d3ad13f11788 100644
>>>> --- a/kernel/auditsc.c
>>>> +++ b/kernel/auditsc.c
>>>> @@ -1187,21 +1184,18 @@ static void show_special(struct audit_context *context, int *call_panic)
>>>>                              context->socketcall.args[i]);
>>>>              break; }
>>>>      case AUDIT_IPC: {
>>>> -            u32 osid = context->ipc.osid;
>>>> +            struct lsmblob *olsm = &context->ipc.olsm;
>>>>
>>>>              audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
>>>>                               from_kuid(&init_user_ns, context->ipc.uid),
>>>>                               from_kgid(&init_user_ns, context->ipc.gid),
>>>>                               context->ipc.mode);
>>>> -            if (osid) {
>>>> +            if (lsmblob_is_set(olsm)) {
>>>>                      struct lsmcontext lsmcxt;
>>>> -                    struct lsmblob blob;
>>>>
>>>> -                    lsmblob_init(&blob, osid);
>>>> -                    if (security_secid_to_secctx(&blob, &lsmcxt)) {
>>>> -                            audit_log_format(ab, " osid=%u", osid);
>>> I am not comfortable just dropping this I would think logging all secids is the
>>> correct action here.
>>>
>>>
>>>> +                    if (security_secid_to_secctx(olsm, &lsmcxt))
>>>>                              *call_panic = 1;
>>>> -                    } else {
>>>> +                    else {
>>>>                              audit_log_format(ab, " obj=%s", lsmcxt.context);
>>>>                              security_release_secctx(&lsmcxt);
>>>>                      }
> 


^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob
  2019-06-25  2:14         ` John Johansen
@ 2019-06-25  2:42           ` Paul Moore
  2019-06-25 15:30             ` Casey Schaufler
  0 siblings, 1 reply; 81+ messages in thread
From: Paul Moore @ 2019-06-25  2:42 UTC (permalink / raw)
  To: John Johansen
  Cc: Casey Schaufler, casey.schaufler, James Morris,
	linux-security-module, selinux, keescook, penguin-kernel,
	Stephen Smalley, Eric Paris, linux-audit

On Mon, Jun 24, 2019 at 10:15 PM John Johansen
<john.johansen@canonical.com> wrote:
> On 6/24/19 6:46 PM, Paul Moore wrote:
> > On Mon, Jun 24, 2019 at 9:01 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> >> On 6/24/2019 2:33 PM, John Johansen wrote:
> >>> On 6/21/19 11:52 AM, Casey Schaufler wrote:
> >>>> Change the audit code to store full lsmblob data instead of
> >>>> a single u32 secid. This allows for multiple security modules
> >>>> to use the audit system at the same time. It also allows the
> >>>> removal of scaffolding code that was included during the
> >>>> revision of LSM interfaces.
> >>>>
> >>>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> >>> I know Kees raised this too, but I haven't seen a reply
> >>>
> >>> Eric (Paul is already CCed): I have directly added you because of
> >>> the question below.
> >>>
> >>> In summary there isn't necessarily a single secid any more, and
> >>> we need to know whether dropping the logging of the secid or
> >>> logging all secids is the correct action.
> >>
> >> It is to be considered that this is an error case. If
> >> everything is working normally you should have produced
> >> a secctx previously, which you'll have included in the
> >> audit record. Including the secid in the record ought to
> >> be pointless, as the secid is strictly an internal token
> >> with no meaning outside the running kernel. You are providing
> >> no security relevant information by providing the secid.
> >> I will grant the possibility that the secid might be useful
> >> in debugging, but for that a pr_warn is more appropriate
> >> than a field in the audit record.
> >
> > FWIW, this probably should have been CC'd to the audit list.
> >
> hrmm indeed, sorry
>
> > I agree that this is an error case (security_secid_to_secctx() failed
> > to resolve the secid) and further that logging the secid, or a
> > collection of secids, has little value the way things currently work.
> > Since secids are a private kernel implementation detail, we don't
> > really display them outside the context of the kernel, including in
> > the audit logs.  Recording a secid in this case doesn't provide
> > anything meaningful since secids aren't recorded in the audit record
> > stream, only the secctxs, and there is no "magic decoder ring" to go
> > between the two in the audit logs, or anywhere else in userspace for
> > that matter.
>
> Okay, thanks. Casey I am good with just a pr_warn here. I just didn't
> have context of why it was going to the audit_log and didn't want
> to change that without some more input.

Hmm.  Actually, let me change my comments slightly ... perhaps what we
should do here is keep the audit_log_format(), but change it from
audit_log_format("osid=%u",...) to audit_log_format("obj=?").  The "?"
is used in audit when we can't determine a piece of information, but
we normally log it.  It wasn't used very widely originally, which is
probably why it isn't in this piece of code.

> >>>> ---
> >>>>  kernel/audit.h   |  6 +++---
> >>>>  kernel/auditsc.c | 38 +++++++++++---------------------------
> >>>>  2 files changed, 14 insertions(+), 30 deletions(-)
> >
> > ...
> >
> >>>> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> >>>> index 0478680cd0a8..d3ad13f11788 100644
> >>>> --- a/kernel/auditsc.c
> >>>> +++ b/kernel/auditsc.c
> >>>> @@ -1187,21 +1184,18 @@ static void show_special(struct audit_context *context, int *call_panic)
> >>>>                              context->socketcall.args[i]);
> >>>>              break; }
> >>>>      case AUDIT_IPC: {
> >>>> -            u32 osid = context->ipc.osid;
> >>>> +            struct lsmblob *olsm = &context->ipc.olsm;
> >>>>
> >>>>              audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
> >>>>                               from_kuid(&init_user_ns, context->ipc.uid),
> >>>>                               from_kgid(&init_user_ns, context->ipc.gid),
> >>>>                               context->ipc.mode);
> >>>> -            if (osid) {
> >>>> +            if (lsmblob_is_set(olsm)) {
> >>>>                      struct lsmcontext lsmcxt;
> >>>> -                    struct lsmblob blob;
> >>>>
> >>>> -                    lsmblob_init(&blob, osid);
> >>>> -                    if (security_secid_to_secctx(&blob, &lsmcxt)) {
> >>>> -                            audit_log_format(ab, " osid=%u", osid);
> >>> I am not comfortable just dropping this I would think logging all secids is the
> >>> correct action here.
> >>>
> >>>
> >>>> +                    if (security_secid_to_secctx(olsm, &lsmcxt))
> >>>>                              *call_panic = 1;
> >>>> -                    } else {
> >>>> +                    else {
> >>>>                              audit_log_format(ab, " obj=%s", lsmcxt.context);
> >>>>                              security_release_secctx(&lsmcxt);
> >>>>                      }

-- 
paul moore
www.paul-moore.com

^ permalink raw reply	[flat|nested] 81+ messages in thread

* Re: [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob
  2019-06-25  2:42           ` Paul Moore
@ 2019-06-25 15:30             ` Casey Schaufler
  0 siblings, 0 replies; 81+ messages in thread
From: Casey Schaufler @ 2019-06-25 15:30 UTC (permalink / raw)
  To: Paul Moore, John Johansen
  Cc: casey.schaufler, James Morris, linux-security-module, selinux,
	keescook, penguin-kernel, Stephen Smalley, Eric Paris,
	linux-audit, casey

On 6/24/2019 7:42 PM, Paul Moore wrote:
> On Mon, Jun 24, 2019 at 10:15 PM John Johansen
> <john.johansen@canonical.com> wrote:
>> On 6/24/19 6:46 PM, Paul Moore wrote:
>>> On Mon, Jun 24, 2019 at 9:01 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
>>>> On 6/24/2019 2:33 PM, John Johansen wrote:
>>>>> On 6/21/19 11:52 AM, Casey Schaufler wrote:
>>>>>> Change the audit code to store full lsmblob data instead of
>>>>>> a single u32 secid. This allows for multiple security modules
>>>>>> to use the audit system at the same time. It also allows the
>>>>>> removal of scaffolding code that was included during the
>>>>>> revision of LSM interfaces.
>>>>>>
>>>>>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>>>>> I know Kees raised this too, but I haven't seen a reply
>>>>>
>>>>> Eric (Paul is already CCed): I have directly added you because of
>>>>> the question below.
>>>>>
>>>>> In summary there isn't necessarily a single secid any more, and
>>>>> we need to know whether dropping the logging of the secid or
>>>>> logging all secids is the correct action.
>>>> It is to be considered that this is an error case. If
>>>> everything is working normally you should have produced
>>>> a secctx previously, which you'll have included in the
>>>> audit record. Including the secid in the record ought to
>>>> be pointless, as the secid is strictly an internal token
>>>> with no meaning outside the running kernel. You are providing
>>>> no security relevant information by providing the secid.
>>>> I will grant the possibility that the secid might be useful
>>>> in debugging, but for that a pr_warn is more appropriate
>>>> than a field in the audit record.
>>> FWIW, this probably should have been CC'd to the audit list.
>>>
>> hrmm indeed, sorry
>>
>>> I agree that this is an error case (security_secid_to_secctx() failed
>>> to resolve the secid) and further that logging the secid, or a
>>> collection of secids, has little value the way things currently work.
>>> Since secids are a private kernel implementation detail, we don't
>>> really display them outside the context of the kernel, including in
>>> the audit logs.  Recording a secid in this case doesn't provide
>>> anything meaningful since secids aren't recorded in the audit record
>>> stream, only the secctxs, and there is no "magic decoder ring" to go
>>> between the two in the audit logs, or anywhere else in userspace for
>>> that matter.
>> Okay, thanks. Casey I am good with just a pr_warn here. I just didn't
>> have context of why it was going to the audit_log and didn't want
>> to change that without some more input.
> Hmm.  Actually, let me change my comments slightly ... perhaps what we
> should do here is keep the audit_log_format(), but change it from
> audit_log_format("osid=%u",...) to audit_log_format("obj=?").  The "?"
> is used in audit when we can't determine a piece of information, but
> we normally log it.  It wasn't used very widely originally, which is
> probably why it isn't in this piece of code.

Works for me. I'll make the change. Thank you.
??


^ permalink raw reply	[flat|nested] 81+ messages in thread

end of thread, other threads:[~2019-06-25 15:30 UTC | newest]

Thread overview: 81+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
2019-06-21 18:52 ` [PATCH v3 01/24] LSM: Infrastructure management of the superblock Casey Schaufler
2019-06-24 18:31   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 02/24] LSM: Infrastructure management of the sock security Casey Schaufler
2019-06-24 18:33   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 03/24] LSM: Infrastructure management of the key blob Casey Schaufler
2019-06-24 18:33   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 04/24] LSM: Create and manage the lsmblob data structure Casey Schaufler
2019-06-22 22:42   ` Kees Cook
2019-06-24 18:38   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 05/24] Use lsmblob in security_audit_rule_match Casey Schaufler
2019-06-22 22:43   ` Kees Cook
2019-06-24 18:39   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 06/24] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
2019-06-22 22:43   ` Kees Cook
2019-06-24 18:38   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 07/24] net: Prepare UDS for secuirty module stacking Casey Schaufler
2019-06-22 22:43   ` Kees Cook
2019-06-24 18:39   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 08/24] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
2019-06-22 22:44   ` Kees Cook
2019-06-24 18:38   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 09/24] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
2019-06-22 22:44   ` Kees Cook
2019-06-24 18:39   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 10/24] Use lsmblob in security_ipc_getsecid Casey Schaufler
2019-06-22 22:48   ` Kees Cook
2019-06-24 16:39     ` Casey Schaufler
2019-06-24 17:20       ` Casey Schaufler
2019-06-24 21:09       ` Kees Cook
2019-06-24 18:39   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 11/24] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
2019-06-22 22:49   ` Kees Cook
2019-06-24 18:40   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 12/24] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
2019-06-22 22:49   ` Kees Cook
2019-06-24 18:40   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 13/24] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
2019-06-22 22:50   ` Kees Cook
2019-06-24 18:40   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 14/24] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
2019-06-22 22:51   ` Kees Cook
2019-06-24 18:40   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 15/24] LSM: Specify which LSM to display Casey Schaufler
2019-06-22 22:51   ` Kees Cook
2019-06-24 18:48   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 16/24] LSM: Ensure the correct LSM context releaser Casey Schaufler
2019-06-22 22:52   ` Kees Cook
2019-06-24 21:46   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 17/24] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2019-06-22 22:52   ` Kees Cook
2019-06-24 21:46   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 18/24] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
2019-06-22 22:54   ` Kees Cook
2019-06-24 21:46   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 19/24] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
2019-06-22 22:56   ` Kees Cook
2019-06-24 21:46   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 20/24] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
2019-06-22 22:57   ` Kees Cook
2019-06-24 21:47   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob Casey Schaufler
2019-06-22 23:12   ` Kees Cook
2019-06-24 21:33   ` John Johansen
2019-06-25  1:01     ` Casey Schaufler
2019-06-25  1:46       ` Paul Moore
2019-06-25  2:14         ` John Johansen
2019-06-25  2:42           ` Paul Moore
2019-06-25 15:30             ` Casey Schaufler
2019-06-21 18:52 ` [PATCH v3 22/24] LSM: Return the lsmblob slot on initialization Casey Schaufler
2019-06-22 23:13   ` Kees Cook
2019-06-24 21:39     ` John Johansen
2019-06-24 21:50       ` Kees Cook
2019-06-24 21:53       ` Casey Schaufler
2019-06-24 21:47   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 23/24] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
2019-06-22 23:15   ` Kees Cook
2019-06-24 21:44   ` John Johansen
2019-06-21 18:52 ` [PATCH v3 24/24] AppArmor: Remove the exclusive flag Casey Schaufler
2019-06-22 23:15   ` Kees Cook
2019-06-24 21:45   ` John Johansen

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