[PATCH v13 00/25] LSM: Module stacking for AppArmor

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* [PATCH v13 00/25] LSM: Module stacking for AppArmor
       [not found] <20191224235939.7483-1-casey.ref@schaufler-ca.com>
@ 2019-12-24 23:59 ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 01/25] LSM: Infrastructure management of the sock security Casey Schaufler
                     ` (25 more replies)
  0 siblings, 26 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

v13: Rebase to 5.5-rc2
     Incorporate feedback from v12
     - Print lsmblob size with %z (Patch 0002)
     - Convert lockdown LSM initialization. (Patch 0002)
     - Restore error check in nft_secmark_compute_secid (Patch 0006)
     - Correct blob scaffolding in ima_must_appraise() (Patch 0009)
     - Make security_setprocattr() clearer (Patch 0013)
     - Use lsm_task_display more widely (Patch 0013)
     - Use passed size in lsmcontext_init() (Patch 0014)
     - Don't add a smack_release_secctx() hook (Patch 0014)
     - Don't print warning in security_release_secctx() (Patch 0014)
     - Don't duplicate the label in nfs4_label_init_security() (Patch 0016)
     - Remove reviewed-by as code has significant change (Patch 0016)
     - Send the entire lsmblob for Tag 6 (Patch 0019)
     - Fix description of socket_getpeersec_stream parameters (Patch 0023)
     - Retain LSMBLOB_FIRST. What was I thinking? (Patch 0023)
     - Add compound context to LSM documentation (Patch 0023)

v12: Rebase to 5.5-rc1
     Fixed a couple of incorrect contractions in the text.

v11: Rebase to 5.4-rc6
     Incorporate feedback from v10
     - Disambiguate reading /proc/.../attr/display by restricting
       all use of the interface to the current process.
     - Fix a merge error in AppArmor's display attribute check

v10: Ask the security modules if the display can be changed.

v9: There is no version 9

v8: Incorporate feedback from v7
    - Minor clean-up in display value management
    - refactor "compound" context creation to use a common
      append_ctx() function.

v7: Incorporate feedback from v6
    - Make setting the display a privileged operation. The
      availability of compound contexts reduces the need for
      setting the display.

v6: Incorporate feedback from v5
    - Add subj_<lsm>= and obj_<lsm>= fields to audit records
    - Add /proc/.../attr/context to get the full context in
      lsmname\0value\0... format as suggested by Simon McVittie
    - Add SO_PEERCONTEXT for getsockopt() to get the full context
      in the same format, also suggested by Simon McVittie.
    - Add /sys/kernel/security/lsm_display_default to provide
      the display default value.

v5: Incorporate feedback from v4
    - Initialize the lsmcontext in security_secid_to_secctx()
    - Clear the lsmcontext in all security_release_secctx() cases
    - Don't use the "display" on strictly internal context
      interfaces.
    - The SELinux binder hooks check for cases where the context
      "display" isn't compatible with SELinux.

v4: Incorporate feedback from v3
    - Mark new lsm_<blob>_alloc functions static
    - Replace the lsm and slot fields of the security_hook_list
      with a pointer to a LSM allocated lsm_id structure. The
      LSM identifies if it needs a slot explicitly. Use the
      lsm_id rather than make security_add_hooks return the
      slot value.
    - Validate slot values used in security.c
    - Reworked the "display" process attribute handling so that
      it works right and doesn't use goofy list processing.
    - fix display value check in dentry_init_security
    - Replace audit_log of secids with '?' instead of deleting
      the audit log

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.

Patche 0001 moves management of the sock security blob from the individual
modules to the infrastructure.

Patches 0002-0012 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 requests one.
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 0013 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/self/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. Setting the
display requires that all modules using the /proc interfaces
allow the transition. The "display" of other processess
can be neither read nor written. All suggested cases
for reading the display of a different process have race
conditions.

Patch 0014 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 0015-0017 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.

The Netlabel code is converted to save lsmblob structures
instead of secids in Patches 0018-0019.

Patch 0020 adds checks to the binder hooks which verify
that if both ends of a transaction use the same "display".

Patches 0021-0022 add addition data to the audit records
to identify the LSM specific data for all active modules.

Patches 0023-0024 add new interfaces for getting the
compound security contexts.

Finally, with all interference on the AppArmor hooks
removed, Patch 0025 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". The sockperf and dbench results
are on the order of 0.2% to 0.8% difference, with
better performance being as common as worse. The
benchmarks were run with AppArmor and Smack on Ubuntu.

https://github.com/cschaufler/lsm-stacking.git#stack-5.5-rc2-v13

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 Documentation/security/lsm.rst          |  15 +
 arch/alpha/include/uapi/asm/socket.h    |   1 +
 arch/mips/include/uapi/asm/socket.h     |   1 +
 arch/parisc/include/uapi/asm/socket.h   |   1 +
 arch/sparc/include/uapi/asm/socket.h    |   1 +
 drivers/android/binder.c                |  26 +-
 fs/ceph/xattr.c                         |   6 +-
 fs/nfs/nfs4proc.c                       |  11 +-
 fs/nfsd/nfs4xdr.c                       |  20 +-
 fs/proc/base.c                          |   2 +
 include/linux/audit.h                   |   1 +
 include/linux/cred.h                    |   3 +-
 include/linux/lsm_hooks.h               |  37 +-
 include/linux/security.h                | 172 ++++++++--
 include/net/af_unix.h                   |   2 +-
 include/net/netlabel.h                  |   8 +-
 include/net/scm.h                       |  15 +-
 include/uapi/asm-generic/socket.h       |   1 +
 kernel/audit.c                          |  72 +++-
 kernel/audit.h                          |   9 +-
 kernel/audit_fsnotify.c                 |   1 +
 kernel/auditfilter.c                    |  10 +-
 kernel/auditsc.c                        | 127 ++++---
 kernel/cred.c                           |  12 +-
 net/core/sock.c                         |   7 +-
 net/ipv4/cipso_ipv4.c                   |  23 +-
 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                |  12 +-
 net/netfilter/xt_SECMARK.c              |   5 +-
 net/netlabel/netlabel_kapi.c            |   6 +-
 net/netlabel/netlabel_unlabeled.c       |  98 +++---
 net/netlabel/netlabel_unlabeled.h       |   2 +-
 net/netlabel/netlabel_user.c            |  13 +-
 net/netlabel/netlabel_user.h            |   6 +-
 net/unix/af_unix.c                      |   6 +-
 net/xfrm/xfrm_policy.c                  |   2 +
 net/xfrm/xfrm_state.c                   |   2 +
 security/apparmor/include/apparmor.h    |   3 +-
 security/apparmor/include/net.h         |   6 +-
 security/apparmor/lsm.c                 | 117 +++----
 security/commoncap.c                    |   7 +-
 security/integrity/ima/ima.h            |  15 +-
 security/integrity/ima/ima_api.c        |  11 +-
 security/integrity/ima/ima_appraise.c   |   6 +-
 security/integrity/ima/ima_main.c       |  42 +--
 security/integrity/ima/ima_policy.c     |  19 +-
 security/integrity/integrity_audit.c    |   1 +
 security/loadpin/loadpin.c              |   8 +-
 security/lockdown/lockdown.c            |   7 +-
 security/safesetid/lsm.c                |   8 +-
 security/security.c                     | 586 +++++++++++++++++++++++++++++---
 security/selinux/hooks.c                | 109 +++---
 security/selinux/include/classmap.h     |   2 +-
 security/selinux/include/objsec.h       |   5 +
 security/selinux/include/security.h     |   1 +
 security/selinux/netlabel.c             |  25 +-
 security/selinux/ss/services.c          |   4 +-
 security/smack/smack.h                  |   6 +
 security/smack/smack_lsm.c              | 110 +++---
 security/smack/smack_netfilter.c        |   8 +-
 security/smack/smackfs.c                |  10 +-
 security/tomoyo/tomoyo.c                |   8 +-
 security/yama/yama_lsm.c                |   7 +-
 66 files changed, 1376 insertions(+), 560 deletions(-)

^ permalink raw reply	[flat|nested] 50+ messages in thread

* [PATCH v13 01/25] LSM: Infrastructure management of the sock security
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 02/25] LSM: Create and manage the lsmblob data structure Casey Schaufler
                     ` (24 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
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 20d8cf194fb7..c2b1af29a8f0 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2095,6 +2095,7 @@ struct lsm_blob_sizes {
 	int	lbs_cred;
 	int	lbs_file;
 	int	lbs_inode;
+	int	lbs_sock;
 	int	lbs_ipc;
 	int	lbs_msg_msg;
 	int	lbs_task;
diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h
index 2431c011800d..5b6f52c62058 100644
--- a/security/apparmor/include/net.h
+++ b/security/apparmor/include/net.h
@@ -51,7 +51,11 @@ 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 b621ad74f54a..61b24f4eb355 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -766,33 +766,15 @@ 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);
 }
 
 /**
@@ -801,8 +783,8 @@ 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);
@@ -853,7 +835,7 @@ 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);
@@ -1038,7 +1020,7 @@ 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;
@@ -1051,7 +1033,7 @@ 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;
@@ -1135,7 +1117,7 @@ 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();
@@ -1145,7 +1127,7 @@ 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;
@@ -1162,6 +1144,7 @@ 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 = {
@@ -1198,7 +1181,6 @@ 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),
 
@@ -1749,7 +1731,7 @@ 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 cd2d18d2d279..7fb6e5bcf6ec 100644
--- a/security/security.c
+++ b/security/security.c
@@ -28,6 +28,7 @@
 #include <linux/string.h>
 #include <linux/msg.h>
 #include <net/flow.h>
+#include <net/sock.h>
 
 #define MAX_LSM_EVM_XATTR	2
 
@@ -169,6 +170,7 @@ 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_task, &blob_sizes.lbs_task);
 }
 
@@ -304,6 +306,7 @@ 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("task blob size     = %d\n", blob_sizes.lbs_task);
 
 	/*
@@ -622,6 +625,28 @@ static int lsm_msg_msg_alloc(struct msg_msg *mp)
 	return 0;
 }
 
+/**
+ * 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.
+ */
+static 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_early_task - during initialization allocate a composite task blob
  * @task: the task that needs a blob
@@ -2066,12 +2091,21 @@ 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 116b4d644f68..0839b2fbbf9b 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4475,7 +4475,7 @@ 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,};
 
@@ -4532,7 +4532,7 @@ 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 */
@@ -4548,8 +4548,8 @@ 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;
@@ -4564,7 +4564,7 @@ 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;
 
@@ -4699,7 +4699,7 @@ 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);
@@ -4878,9 +4878,9 @@ 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;
@@ -4912,8 +4912,8 @@ 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,};
 
@@ -4955,7 +4955,7 @@ 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,};
@@ -4988,7 +4988,7 @@ 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;
@@ -5056,13 +5056,15 @@ 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,
+					    char __user *optval,
+					    int __user *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 ||
@@ -5122,34 +5124,27 @@ 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;
@@ -5163,7 +5158,7 @@ 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;
 	}
@@ -5173,7 +5168,7 @@ 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)
@@ -5188,7 +5183,7 @@ 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;
@@ -5339,8 +5334,8 @@ 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.
@@ -5357,7 +5352,7 @@ 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;
@@ -5378,7 +5373,7 @@ 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;
@@ -5395,7 +5390,7 @@ 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))
@@ -5479,7 +5474,7 @@ 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
@@ -5520,7 +5515,7 @@ 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;
@@ -5661,7 +5656,7 @@ 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;
@@ -5700,7 +5695,7 @@ 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;
@@ -5792,7 +5787,7 @@ 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
@@ -5821,7 +5816,7 @@ 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;
 	}
@@ -6801,6 +6796,7 @@ 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),
 };
 
 #ifdef CONFIG_PERF_EVENTS
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index a4a86cbcfb0a..572c88700393 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -189,4 +189,9 @@ static inline u32 current_sid(void)
 	return tsec->sid;
 }
 
+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 abaab7683840..6a94b31b5472 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -17,6 +17,7 @@
 #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>
@@ -67,7 +68,7 @@ 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)
@@ -100,7 +101,7 @@ 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)
@@ -235,7 +236,7 @@ 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;
@@ -273,7 +274,7 @@ 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_in addr4;
 	struct sockaddr_in6 addr6;
 
@@ -352,7 +353,7 @@ 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;
@@ -370,8 +371,8 @@ 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;
 }
@@ -389,7 +390,7 @@ 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)
@@ -504,7 +505,7 @@ 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) &&
@@ -542,7 +543,7 @@ 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
@@ -581,7 +582,7 @@ 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 62529f382942..2836540f9577 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -372,6 +372,11 @@ 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;
+}
+
 /*
  * Is the directory transmuting?
  */
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index ecea41ce919b..4cecdfdcd913 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1455,7 +1455,7 @@ 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;
@@ -1837,7 +1837,7 @@ 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
@@ -2244,11 +2244,7 @@ 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.
@@ -2262,11 +2258,10 @@ 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
@@ -2275,7 +2270,6 @@ 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) {
@@ -2288,9 +2282,8 @@ 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
@@ -2408,7 +2401,7 @@ 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;
 
 	/*
@@ -2453,7 +2446,7 @@ 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();
@@ -2529,7 +2522,7 @@ 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;
 
@@ -2617,7 +2610,7 @@ 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;
@@ -2711,7 +2704,7 @@ 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;
@@ -2759,7 +2752,7 @@ 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;
 	}
@@ -2784,8 +2777,8 @@ 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;
@@ -2843,7 +2836,7 @@ 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) {
@@ -3585,9 +3578,9 @@ 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
@@ -3633,8 +3626,8 @@ 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;
 
@@ -3671,7 +3664,7 @@ 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;
@@ -3844,7 +3837,7 @@ 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;
@@ -3965,7 +3958,7 @@ 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;
@@ -4015,7 +4008,7 @@ 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:
@@ -4028,7 +4021,7 @@ 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) {
@@ -4066,7 +4059,7 @@ 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() */
@@ -4086,7 +4079,7 @@ 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;
@@ -4185,7 +4178,7 @@ 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) {
@@ -4589,6 +4582,7 @@ 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),
 };
 
 static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
@@ -4698,7 +4692,9 @@ 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 fc7399b45373..635e2339579e 100644
--- a/security/smack/smack_netfilter.c
+++ b/security/smack/smack_netfilter.c
@@ -28,8 +28,8 @@ 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;
 	}
@@ -46,8 +46,8 @@ 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] 50+ messages in thread

* [PATCH v13 02/25] LSM: Create and manage the lsmblob data structure.
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 01/25] LSM: Infrastructure management of the sock security Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-25 20:34     ` Mickaël Salaün
  2019-12-24 23:59   ` [PATCH v13 03/25] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
                     ` (23 subsequent siblings)
  25 siblings, 1 reply; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

A new lsm_id structure, which contains the name
of the LSM and its slot number, is created. There
is an instance for each LSM, which assigns the name
and passes it to the infrastructure to set the slot.

Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h    | 12 ++++++--
 include/linux/security.h     | 58 ++++++++++++++++++++++++++++++++++++
 security/apparmor/lsm.c      |  7 ++++-
 security/commoncap.c         |  7 ++++-
 security/loadpin/loadpin.c   |  8 ++++-
 security/lockdown/lockdown.c |  7 ++++-
 security/safesetid/lsm.c     |  8 ++++-
 security/security.c          | 28 +++++++++++++----
 security/selinux/hooks.c     |  8 ++++-
 security/smack/smack_lsm.c   |  7 ++++-
 security/tomoyo/tomoyo.c     |  8 ++++-
 security/yama/yama_lsm.c     |  7 ++++-
 12 files changed, 148 insertions(+), 17 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index c2b1af29a8f0..7eb808cde051 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2077,6 +2077,14 @@ struct security_hook_heads {
 #endif
 } __randomize_layout;
 
+/*
+ * Information that identifies a security module.
+ */
+struct lsm_id {
+	const char	*lsm;	/* Name of the LSM */
+	int		slot;	/* Slot in lsmblob if one is allocated */
+};
+
 /*
  * Security module hook list structure.
  * For use with generic list macros for common operations.
@@ -2085,7 +2093,7 @@ struct security_hook_list {
 	struct hlist_node		list;
 	struct hlist_head		*head;
 	union security_list_options	hook;
-	char				*lsm;
+	struct lsm_id			*lsmid;
 } __randomize_layout;
 
 /*
@@ -2114,7 +2122,7 @@ 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);
+			       struct lsm_id *lsmid);
 
 #define LSM_FLAG_LEGACY_MAJOR	BIT(0)
 #define LSM_FLAG_EXCLUSIVE	BIT(1)
diff --git a/include/linux/security.h b/include/linux/security.h
index 3e8d4bacd59d..b74dc70088ca 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -128,6 +128,64 @@ enum lockdown_reason {
 	LOCKDOWN_CONFIDENTIALITY_MAX,
 };
 
+/*
+ * Data exported by the security modules
+ *
+ * Any LSM that provides secid or secctx based hooks must be included.
+ */
+#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	/* Not a valid LSM slot number */
+#define LSMBLOB_NEEDED		-2	/* Slot requested on initialization */
+#define LSMBLOB_NOT_NEEDED	-3	/* Slot not requested */
+
+/**
+ * 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)
+{
+	struct lsmblob empty = {};
+
+	return !!memcmp(blob, &empty, sizeof(*blob));
+}
+
+/**
+ * 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)
+{
+	return !memcmp(bloba, blobb, sizeof(*bloba));
+}
+
 /* 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/apparmor/lsm.c b/security/apparmor/lsm.c
index 61b24f4eb355..146d75e5e021 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1147,6 +1147,11 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
 	.lbs_sock = sizeof(struct aa_sk_ctx),
 };
 
+static struct lsm_id apparmor_lsmid __lsm_ro_after_init = {
+	.lsm  = "apparmor",
+	.slot = LSMBLOB_NEEDED
+};
+
 static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
 	LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
@@ -1847,7 +1852,7 @@ static int __init apparmor_init(void)
 		goto buffers_out;
 	}
 	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
-				"apparmor");
+				&apparmor_lsmid);
 
 	/* Report that AppArmor successfully initialized */
 	apparmor_initialized = 1;
diff --git a/security/commoncap.c b/security/commoncap.c
index f4ee0ae106b2..9dcfd2a0e891 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -1339,6 +1339,11 @@ int cap_mmap_file(struct file *file, unsigned long reqprot,
 
 #ifdef CONFIG_SECURITY
 
+static struct lsm_id capability_lsmid __lsm_ro_after_init = {
+	.lsm  = "capability",
+	.slot = LSMBLOB_NOT_NEEDED
+};
+
 static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(capable, cap_capable),
 	LSM_HOOK_INIT(settime, cap_settime),
@@ -1363,7 +1368,7 @@ static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
 static int __init capability_init(void)
 {
 	security_add_hooks(capability_hooks, ARRAY_SIZE(capability_hooks),
-				"capability");
+			   &capability_lsmid);
 	return 0;
 }
 
diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c
index ee5cb944f4ad..86317e78899f 100644
--- a/security/loadpin/loadpin.c
+++ b/security/loadpin/loadpin.c
@@ -180,6 +180,11 @@ static int loadpin_load_data(enum kernel_load_data_id id)
 	return loadpin_read_file(NULL, (enum kernel_read_file_id) id);
 }
 
+static struct lsm_id loadpin_lsmid __lsm_ro_after_init = {
+	.lsm  = "loadpin",
+	.slot = LSMBLOB_NOT_NEEDED
+};
+
 static struct security_hook_list loadpin_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(sb_free_security, loadpin_sb_free_security),
 	LSM_HOOK_INIT(kernel_read_file, loadpin_read_file),
@@ -227,7 +232,8 @@ static int __init loadpin_init(void)
 	pr_info("ready to pin (currently %senforcing)\n",
 		enforce ? "" : "not ");
 	parse_exclude();
-	security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks), "loadpin");
+	security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks),
+			   &loadpin_lsmid);
 	return 0;
 }
 
diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c
index b2f87015d6e9..91662325e450 100644
--- a/security/lockdown/lockdown.c
+++ b/security/lockdown/lockdown.c
@@ -102,6 +102,11 @@ static struct security_hook_list lockdown_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(locked_down, lockdown_is_locked_down),
 };
 
+static struct lsm_id lockdown_lsmid __lsm_ro_after_init = {
+	.lsm = "landlock",
+	.slot = LSMBLOB_NOT_NEEDED
+};
+
 static int __init lockdown_lsm_init(void)
 {
 #if defined(CONFIG_LOCK_DOWN_KERNEL_FORCE_INTEGRITY)
@@ -110,7 +115,7 @@ static int __init lockdown_lsm_init(void)
 	lock_kernel_down("Kernel configuration", LOCKDOWN_CONFIDENTIALITY_MAX);
 #endif
 	security_add_hooks(lockdown_hooks, ARRAY_SIZE(lockdown_hooks),
-			   "lockdown");
+			   &lockdown_lsmid);
 	return 0;
 }
 
diff --git a/security/safesetid/lsm.c b/security/safesetid/lsm.c
index 7760019ad35d..950dfb7f931e 100644
--- a/security/safesetid/lsm.c
+++ b/security/safesetid/lsm.c
@@ -149,6 +149,11 @@ static int safesetid_task_fix_setuid(struct cred *new,
 	return -EACCES;
 }
 
+static struct lsm_id safesetid_lsmid __lsm_ro_after_init = {
+	.lsm  = "safesetid",
+	.slot = LSMBLOB_NOT_NEEDED
+};
+
 static struct security_hook_list safesetid_security_hooks[] = {
 	LSM_HOOK_INIT(task_fix_setuid, safesetid_task_fix_setuid),
 	LSM_HOOK_INIT(capable, safesetid_security_capable)
@@ -157,7 +162,8 @@ static struct security_hook_list safesetid_security_hooks[] = {
 static int __init safesetid_security_init(void)
 {
 	security_add_hooks(safesetid_security_hooks,
-			   ARRAY_SIZE(safesetid_security_hooks), "safesetid");
+			   ARRAY_SIZE(safesetid_security_hooks),
+			   &safesetid_lsmid);
 
 	/* Report that SafeSetID successfully initialized */
 	safesetid_initialized = 1;
diff --git a/security/security.c b/security/security.c
index 7fb6e5bcf6ec..87fc70f77660 100644
--- a/security/security.c
+++ b/security/security.c
@@ -308,6 +308,7 @@ static void __init ordered_lsm_init(void)
 	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("task blob size     = %d\n", blob_sizes.lbs_task);
+	init_debug("lsmblob size       = %zu\n", sizeof(struct lsmblob));
 
 	/*
 	 * Create any kmem_caches needed for blobs
@@ -435,21 +436,36 @@ static int lsm_append(const 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
  * @count: the number of hooks to add
- * @lsm: the name of the security module
+ * @lsmid: the the identification information for 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)
+			       struct lsm_id *lsmid)
 {
 	int i;
 
+	if (lsmid->slot == LSMBLOB_NEEDED) {
+		if (lsm_slot >= LSMBLOB_ENTRIES)
+			panic("%s Too many LSMs registered.\n", __func__);
+		lsmid->slot = lsm_slot++;
+		init_debug("%s assigned lsmblob slot %d\n", lsmid->lsm,
+			   lsmid->slot);
+	}
+
 	for (i = 0; i < count; i++) {
-		hooks[i].lsm = lsm;
+		hooks[i].lsmid = lsmid;
 		hlist_add_tail_rcu(&hooks[i].list, hooks[i].head);
 	}
 
@@ -458,7 +474,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
 	 * and fix this up afterwards.
 	 */
 	if (slab_is_available()) {
-		if (lsm_append(lsm, &lsm_names) < 0)
+		if (lsm_append(lsmid->lsm, &lsm_names) < 0)
 			panic("%s - Cannot get early memory.\n", __func__);
 	}
 }
@@ -1906,7 +1922,7 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
 	struct security_hook_list *hp;
 
 	hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
-		if (lsm != NULL && strcmp(lsm, hp->lsm))
+		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
 			continue;
 		return hp->hook.getprocattr(p, name, value);
 	}
@@ -1919,7 +1935,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 	struct security_hook_list *hp;
 
 	hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
-		if (lsm != NULL && strcmp(lsm, hp->lsm))
+		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
 			continue;
 		return hp->hook.setprocattr(name, value, size);
 	}
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 0839b2fbbf9b..97f2ee6e4080 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6860,6 +6860,11 @@ static int selinux_perf_event_write(struct perf_event *event)
 }
 #endif
 
+static struct lsm_id selinux_lsmid __lsm_ro_after_init = {
+	.lsm  = "selinux",
+	.slot = LSMBLOB_NEEDED
+};
+
 static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
 	LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
@@ -7128,7 +7133,8 @@ static __init int selinux_init(void)
 
 	hashtab_cache_init();
 
-	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
+	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks),
+			   &selinux_lsmid);
 
 	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 4cecdfdcd913..82cbb3eeec76 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4585,6 +4585,11 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
 	.lbs_sock = sizeof(struct socket_smack),
 };
 
+static struct lsm_id smack_lsmid __lsm_ro_after_init = {
+	.lsm  = "smack",
+	.slot = LSMBLOB_NEEDED
+};
+
 static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check),
 	LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
@@ -4783,7 +4788,7 @@ static __init int smack_init(void)
 	/*
 	 * Register with LSM
 	 */
-	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
+	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), &smack_lsmid);
 	smack_enabled = 1;
 
 	pr_info("Smack:  Initializing.\n");
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
index 716c92ec941a..f1968e80f06d 100644
--- a/security/tomoyo/tomoyo.c
+++ b/security/tomoyo/tomoyo.c
@@ -529,6 +529,11 @@ static void tomoyo_task_free(struct task_struct *task)
 	}
 }
 
+static struct lsm_id tomoyo_lsmid __lsm_ro_after_init = {
+	.lsm  = "tomoyo",
+	.slot = LSMBLOB_NOT_NEEDED
+};
+
 /*
  * tomoyo_security_ops is a "struct security_operations" which is used for
  * registering TOMOYO.
@@ -581,7 +586,8 @@ static int __init tomoyo_init(void)
 	struct tomoyo_task *s = tomoyo_task(current);
 
 	/* register ourselves with the security framework */
-	security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo");
+	security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks),
+			   &tomoyo_lsmid);
 	pr_info("TOMOYO Linux initialized\n");
 	s->domain_info = &tomoyo_kernel_domain;
 	atomic_inc(&tomoyo_kernel_domain.users);
diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c
index 94dc346370b1..0f0cf7136929 100644
--- a/security/yama/yama_lsm.c
+++ b/security/yama/yama_lsm.c
@@ -421,6 +421,11 @@ static int yama_ptrace_traceme(struct task_struct *parent)
 	return rc;
 }
 
+static struct lsm_id yama_lsmid __lsm_ro_after_init = {
+	.lsm  = "yama",
+	.slot = LSMBLOB_NOT_NEEDED
+};
+
 static struct security_hook_list yama_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(ptrace_access_check, yama_ptrace_access_check),
 	LSM_HOOK_INIT(ptrace_traceme, yama_ptrace_traceme),
@@ -477,7 +482,7 @@ static inline void yama_init_sysctl(void) { }
 static int __init yama_init(void)
 {
 	pr_info("Yama: becoming mindful.\n");
-	security_add_hooks(yama_hooks, ARRAY_SIZE(yama_hooks), "yama");
+	security_add_hooks(yama_hooks, ARRAY_SIZE(yama_hooks), &yama_lsmid);
 	yama_init_sysctl();
 	return 0;
 }
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 02/25] LSM: Create and manage the lsmblob data structure.
  2019-12-24 23:59   ` [PATCH v13 02/25] LSM: Create and manage the lsmblob data structure Casey Schaufler
@ 2019-12-25 20:34     ` Mickaël Salaün
  0 siblings, 0 replies; 50+ messages in thread
From: Mickaël Salaün @ 2019-12-25 20:34 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul, sds


On 25/12/2019 00:59, 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.
> 
> A new lsm_id structure, which contains the name
> of the LSM and its slot number, is created. There
> is an instance for each LSM, which assigns the name
> and passes it to the infrastructure to set the slot.
> 
> Reviewed-by: John Johansen <john.johansen@canonical.com>
> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---
>   include/linux/lsm_hooks.h    | 12 ++++++--
>   include/linux/security.h     | 58 ++++++++++++++++++++++++++++++++++++
>   security/apparmor/lsm.c      |  7 ++++-
>   security/commoncap.c         |  7 ++++-
>   security/loadpin/loadpin.c   |  8 ++++-
>   security/lockdown/lockdown.c |  7 ++++-
>   security/safesetid/lsm.c     |  8 ++++-
>   security/security.c          | 28 +++++++++++++----
>   security/selinux/hooks.c     |  8 ++++-
>   security/smack/smack_lsm.c   |  7 ++++-
>   security/tomoyo/tomoyo.c     |  8 ++++-
>   security/yama/yama_lsm.c     |  7 ++++-
>   12 files changed, 148 insertions(+), 17 deletions(-)
> 
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index c2b1af29a8f0..7eb808cde051 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -2077,6 +2077,14 @@ struct security_hook_heads {
>   #endif
>   } __randomize_layout;
>   
> +/*
> + * Information that identifies a security module.
> + */
> +struct lsm_id {
> +	const char	*lsm;	/* Name of the LSM */
> +	int		slot;	/* Slot in lsmblob if one is allocated */
> +};
> +
>   /*
>    * Security module hook list structure.
>    * For use with generic list macros for common operations.
> @@ -2085,7 +2093,7 @@ struct security_hook_list {
>   	struct hlist_node		list;
>   	struct hlist_head		*head;
>   	union security_list_options	hook;
> -	char				*lsm;
> +	struct lsm_id			*lsmid;
>   } __randomize_layout;
>   
>   /*
> @@ -2114,7 +2122,7 @@ 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);
> +			       struct lsm_id *lsmid);
>   
>   #define LSM_FLAG_LEGACY_MAJOR	BIT(0)
>   #define LSM_FLAG_EXCLUSIVE	BIT(1)
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 3e8d4bacd59d..b74dc70088ca 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -128,6 +128,64 @@ enum lockdown_reason {
>   	LOCKDOWN_CONFIDENTIALITY_MAX,
>   };
>   
> +/*
> + * Data exported by the security modules
> + *
> + * Any LSM that provides secid or secctx based hooks must be included.
> + */
> +#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	/* Not a valid LSM slot number */
> +#define LSMBLOB_NEEDED		-2	/* Slot requested on initialization */
> +#define LSMBLOB_NOT_NEEDED	-3	/* Slot not requested */
> +
> +/**
> + * 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)
> +{
> +	struct lsmblob empty = {};
> +
> +	return !!memcmp(blob, &empty, sizeof(*blob));
> +}
> +
> +/**
> + * 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)
> +{
> +	return !memcmp(bloba, blobb, sizeof(*bloba));
> +}
> +
>   /* 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/apparmor/lsm.c b/security/apparmor/lsm.c
> index 61b24f4eb355..146d75e5e021 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -1147,6 +1147,11 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
>   	.lbs_sock = sizeof(struct aa_sk_ctx),
>   };
>   
> +static struct lsm_id apparmor_lsmid __lsm_ro_after_init = {
> +	.lsm  = "apparmor",
> +	.slot = LSMBLOB_NEEDED
> +};
> +
>   static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
>   	LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
>   	LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
> @@ -1847,7 +1852,7 @@ static int __init apparmor_init(void)
>   		goto buffers_out;
>   	}
>   	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
> -				"apparmor");
> +				&apparmor_lsmid);
>   
>   	/* Report that AppArmor successfully initialized */
>   	apparmor_initialized = 1;
> diff --git a/security/commoncap.c b/security/commoncap.c
> index f4ee0ae106b2..9dcfd2a0e891 100644
> --- a/security/commoncap.c
> +++ b/security/commoncap.c
> @@ -1339,6 +1339,11 @@ int cap_mmap_file(struct file *file, unsigned long reqprot,
>   
>   #ifdef CONFIG_SECURITY
>   
> +static struct lsm_id capability_lsmid __lsm_ro_after_init = {
> +	.lsm  = "capability",
> +	.slot = LSMBLOB_NOT_NEEDED
> +};
> +
>   static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
>   	LSM_HOOK_INIT(capable, cap_capable),
>   	LSM_HOOK_INIT(settime, cap_settime),
> @@ -1363,7 +1368,7 @@ static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
>   static int __init capability_init(void)
>   {
>   	security_add_hooks(capability_hooks, ARRAY_SIZE(capability_hooks),
> -				"capability");
> +			   &capability_lsmid);
>   	return 0;
>   }
>   
> diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c
> index ee5cb944f4ad..86317e78899f 100644
> --- a/security/loadpin/loadpin.c
> +++ b/security/loadpin/loadpin.c
> @@ -180,6 +180,11 @@ static int loadpin_load_data(enum kernel_load_data_id id)
>   	return loadpin_read_file(NULL, (enum kernel_read_file_id) id);
>   }
>   
> +static struct lsm_id loadpin_lsmid __lsm_ro_after_init = {
> +	.lsm  = "loadpin",
> +	.slot = LSMBLOB_NOT_NEEDED
> +};
> +
>   static struct security_hook_list loadpin_hooks[] __lsm_ro_after_init = {
>   	LSM_HOOK_INIT(sb_free_security, loadpin_sb_free_security),
>   	LSM_HOOK_INIT(kernel_read_file, loadpin_read_file),
> @@ -227,7 +232,8 @@ static int __init loadpin_init(void)
>   	pr_info("ready to pin (currently %senforcing)\n",
>   		enforce ? "" : "not ");
>   	parse_exclude();
> -	security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks), "loadpin");
> +	security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks),
> +			   &loadpin_lsmid);
>   	return 0;
>   }
>   
> diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c
> index b2f87015d6e9..91662325e450 100644
> --- a/security/lockdown/lockdown.c
> +++ b/security/lockdown/lockdown.c
> @@ -102,6 +102,11 @@ static struct security_hook_list lockdown_hooks[] __lsm_ro_after_init = {
>   	LSM_HOOK_INIT(locked_down, lockdown_is_locked_down),
>   };
>   
> +static struct lsm_id lockdown_lsmid __lsm_ro_after_init = {
> +	.lsm = "landlock",

Working on it but not there yet ;)

^ permalink raw reply	[flat|nested] 50+ messages in thread

* [PATCH v13 03/25] LSM: Use lsmblob in security_audit_rule_match
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 01/25] LSM: Infrastructure management of the sock security Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 02/25] LSM: Create and manage the lsmblob data structure Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-31 13:13     ` Mimi Zohar
  2019-12-24 23:59   ` [PATCH v13 04/25] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
                     ` (22 subsequent siblings)
  25 siblings, 1 reply; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h            |  7 ++++---
 kernel/auditfilter.c                |  7 +++++--
 kernel/auditsc.c                    | 14 ++++++++++----
 security/integrity/ima/ima.h        |  4 ++--
 security/integrity/ima/ima_policy.c |  7 +++++--
 security/security.c                 | 18 +++++++++++++++---
 6 files changed, 41 insertions(+), 16 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index b74dc70088ca..9c6dbe248eaf 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1837,7 +1837,8 @@ 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
@@ -1853,8 +1854,8 @@ 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 b0126e9c0743..356db1dd276c 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1325,6 +1325,7 @@ 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:
@@ -1355,8 +1356,10 @@ 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,
-						   f->type, f->op, f->lsm_rule);
+					lsmblob_init(&blob, sid);
+					result = security_audit_rule_match(
+							&blob, f->type,
+							f->op, f->lsm_rule);
 				}
 				break;
 			case AUDIT_EXE:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 4effe01ebbe2..7566e5b1c419 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);
@@ -643,7 +644,9 @@ 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);
 			}
@@ -658,15 +661,17 @@ 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)) {
@@ -678,7 +683,8 @@ 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 df4ca482fb53..d95b0ece7434 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -381,8 +381,8 @@ 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 ef8dfd47c7e3..68fe533f8a4f 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -414,6 +414,7 @@ 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;
 
 		if (!rule->lsm[i].rule)
 			continue;
@@ -423,7 +424,8 @@ 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);
@@ -431,7 +433,8 @@ 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 87fc70f77660..12e1e6223233 100644
--- a/security/security.c
+++ b/security/security.c
@@ -439,7 +439,7 @@ static int lsm_append(const char *new, char **result)
 /*
  * Current index to use while initializing the lsmblob secid list.
  */
-static int lsm_slot __initdata;
+static int lsm_slot __lsm_ro_after_init;
 
 /**
  * security_add_hooks - Add a modules hooks to the hook lists.
@@ -2412,9 +2412,21 @@ 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) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
+					       field, op, lsmrule);
+		if (rc != 0)
+			return rc;
+	}
+	return 0;
 }
 #endif /* CONFIG_AUDIT */
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 03/25] LSM: Use lsmblob in security_audit_rule_match
  2019-12-24 23:59   ` [PATCH v13 03/25] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
@ 2019-12-31 13:13     ` Mimi Zohar
  2020-01-02 23:36       ` Casey Schaufler
  0 siblings, 1 reply; 50+ messages in thread
From: Mimi Zohar @ 2019-12-31 13:13 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul, sds, Janne Karhunen

[Cc'ing Janne Karhunen based on his recent work updating IMA policy
rules LSM id's - commit b16942455193 ("ima: use the lsm policy update
notifier")]

On Tue, 2019-12-24 at 15:59 -0800, Casey Schaufler wrote:
> diff --git a/security/security.c b/security/security.c
> index 87fc70f77660..12e1e6223233 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -439,7 +439,7 @@ static int lsm_append(const char *new, char **result)
>  /*
>   * Current index to use while initializing the lsmblob secid list.
>   */
> -static int lsm_slot __initdata;
> +static int lsm_slot __lsm_ro_after_init;
> 
>  /**
>   * security_add_hooks - Add a modules hooks to the hook lists.
> @@ -2412,9 +2412,21 @@ 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) {
> +		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> +			continue;
> +		rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
> +					       field, op, lsmrule);

IMA's policy rules may be written in terms of LSM labels.  On IMA
policy initialization and, subsequently, when the LSM policy is
updated, IMA correlates LSM labels with LSM ids.  Doesn't
security_audit_rule_init() also need to be updated to walk the LSMs?

The basic assumption with security_audit_rule_match() is that there
isn't any naming overlap.  Is that guaranteed?  With this change, do
the IMA policy rules now need to be LSM qualified?

Mimi

> +		if (rc != 0)
> +			return rc;
> +	}
> +	return 0;
>  }
>  #endif /* CONFIG_AUDIT */


^ permalink raw reply	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 03/25] LSM: Use lsmblob in security_audit_rule_match
  2019-12-31 13:13     ` Mimi Zohar
@ 2020-01-02 23:36       ` Casey Schaufler
  0 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2020-01-02 23:36 UTC (permalink / raw)
  To: Mimi Zohar, casey.schaufler, jmorris, linux-security-module, selinux
  Cc: keescook, john.johansen, penguin-kernel, paul, sds, Janne Karhunen

On 12/31/2019 5:13 AM, Mimi Zohar wrote:
> [Cc'ing Janne Karhunen based on his recent work updating IMA policy
> rules LSM id's - commit b16942455193 ("ima: use the lsm policy update
> notifier")]
>
> On Tue, 2019-12-24 at 15:59 -0800, Casey Schaufler wrote:
>> diff --git a/security/security.c b/security/security.c
>> index 87fc70f77660..12e1e6223233 100644
>> --- a/security/security.c
>> +++ b/security/security.c
>> @@ -439,7 +439,7 @@ static int lsm_append(const char *new, char **result)
>>  /*
>>   * Current index to use while initializing the lsmblob secid list.
>>   */
>> -static int lsm_slot __initdata;
>> +static int lsm_slot __lsm_ro_after_init;
>>
>>  /**
>>   * security_add_hooks - Add a modules hooks to the hook lists.
>> @@ -2412,9 +2412,21 @@ 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) {
>> +		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
>> +			continue;
>> +		rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
>> +					       field, op, lsmrule);
> IMA's policy rules may be written in terms of LSM labels.  On IMA
> policy initialization and, subsequently, when the LSM policy is
> updated, IMA correlates LSM labels with LSM ids.  Doesn't
> security_audit_rule_init() also need to be updated to walk the LSMs?

Yes. I've got a change in test.

>
> The basic assumption with security_audit_rule_match() is that there
> isn't any naming overlap.  Is that guaranteed?

No. A valid SELinux label is also a valid Smack label. If someone
asks to see subj_user=whatever_t both module will look for it.

>   With this change, do
> the IMA policy rules now need to be LSM qualified?

I have a change for that in test, too.

>
> Mimi
>
>> +		if (rc != 0)
>> +			return rc;
>> +	}
>> +	return 0;
>>  }
>>  #endif /* CONFIG_AUDIT */


^ permalink raw reply	[flat|nested] 50+ messages in thread

* [PATCH v13 04/25] LSM: Use lsmblob in security_kernel_act_as
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (2 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 03/25] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 05/25] net: Prepare UDS for security module stacking Casey Schaufler
                     ` (21 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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 its 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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
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      | 14 ++++++++++++--
 4 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/include/linux/cred.h b/include/linux/cred.h
index 18639c069263..03ae0182cba6 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -18,6 +18,7 @@
 
 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 9c6dbe248eaf..322ed9622819 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -437,7 +437,7 @@ 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);
@@ -1043,7 +1043,8 @@ 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 c0a4c12d38b2..846ac4b23c16 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -732,14 +732,14 @@ 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);
 
@@ -755,6 +755,7 @@ EXPORT_SYMBOL(set_security_override);
  */
 int set_security_override_from_ctx(struct cred *new, const char *secctx)
 {
+	struct lsmblob blob;
 	u32 secid;
 	int ret;
 
@@ -762,7 +763,8 @@ 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 12e1e6223233..674042c6f03f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1615,9 +1615,19 @@ 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) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		rc = hp->hook.kernel_act_as(new, blob->secid[hp->lsmid->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] 50+ messages in thread

* [PATCH v13 05/25] net: Prepare UDS for security module stacking
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (3 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 04/25] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 06/25] Use lsmblob in security_secctx_to_secid Casey Schaufler
                     ` (20 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc: netdev@vger.kernel.org
---
 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      | 18 +++++++++++++++---
 6 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 322ed9622819..995faba7393f 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1356,7 +1356,8 @@ 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);
@@ -1494,7 +1495,9 @@ 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 aa3fd61818c4..6cf57d5ac899 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 774babbee045..f0b1d741ab6c 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -138,17 +138,17 @@ 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 674042c6f03f..33563963cd45 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2108,10 +2108,22 @@ 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) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		rc = hp->hook.socket_getpeersec_dgram(sock, skb,
+						&blob->secid[hp->lsmid->slot]);
+		if (rc != 0)
+			break;
+	}
+	return rc;
 }
 EXPORT_SYMBOL(security_socket_getpeersec_dgram);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* [PATCH v13 06/25] Use lsmblob in security_secctx_to_secid
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (4 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 05/25] net: Prepare UDS for security module stacking Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2020-01-07 17:45     ` Stephen Smalley
  2019-12-24 23:59   ` [PATCH v13 07/25] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
                     ` (19 subsequent siblings)
  25 siblings, 1 reply; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h          |  5 +++--
 kernel/cred.c                     |  4 +---
 net/netfilter/nft_meta.c          | 12 +++++++-----
 net/netfilter/xt_SECMARK.c        |  5 ++++-
 net/netlabel/netlabel_unlabeled.c | 14 ++++++++------
 security/security.c               | 18 +++++++++++++++---
 6 files changed, 38 insertions(+), 20 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 995faba7393f..8cae9e4bd760 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -496,7 +496,8 @@ 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);
 int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
@@ -1302,7 +1303,7 @@ 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 846ac4b23c16..7fef90f3f10b 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -756,14 +756,12 @@ 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 9740b554fdb3..259c78d2f371 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -625,21 +625,23 @@ 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)
+	if (!lsmblob_is_set(&blob))
 		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[0] is scaffolding */
+	priv->secid = blob.secid[0];
 	return 0;
 }
 
diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
index 2317721f3ecb..2d68416b4552 100644
--- a/net/netfilter/xt_SECMARK.c
+++ b/net/netfilter/xt_SECMARK.c
@@ -45,13 +45,14 @@ 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",
@@ -59,6 +60,8 @@ 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 d2e4ab8d1cb1..7a5a87f15736 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -881,7 +881,7 @@ 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
@@ -905,12 +905,13 @@ 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);
 }
 
@@ -932,7 +933,7 @@ 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
@@ -954,12 +955,13 @@ 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 33563963cd45..9dc0bbfe567e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1970,10 +1970,22 @@ 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) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		rc = hp->hook.secctx_to_secid(secdata, seclen,
+					      &blob->secid[hp->lsmid->slot]);
+		if (rc != 0)
+			return rc;
+	}
+	return 0;
 }
 EXPORT_SYMBOL(security_secctx_to_secid);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 06/25] Use lsmblob in security_secctx_to_secid
  2019-12-24 23:59   ` [PATCH v13 06/25] Use lsmblob in security_secctx_to_secid Casey Schaufler
@ 2020-01-07 17:45     ` Stephen Smalley
  0 siblings, 0 replies; 50+ messages in thread
From: Stephen Smalley @ 2020-01-07 17:45 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul

On 12/24/19 6:59 PM, 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.
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Reviewed-by: John Johansen <john.johansen@canonical.com>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

This addressed my comment on the previous version, so I'll add my ack. 
However, I noticed that even after the entire series is applied, at 
least some of the scaffolding remains.  Wondering whether that 
scaffolding is completely removed by the next series (i.e. full stacking 
for Smack) or still TBD.

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>

> ---
>   include/linux/security.h          |  5 +++--
>   kernel/cred.c                     |  4 +---
>   net/netfilter/nft_meta.c          | 12 +++++++-----
>   net/netfilter/xt_SECMARK.c        |  5 ++++-
>   net/netlabel/netlabel_unlabeled.c | 14 ++++++++------
>   security/security.c               | 18 +++++++++++++++---
>   6 files changed, 38 insertions(+), 20 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 995faba7393f..8cae9e4bd760 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -496,7 +496,8 @@ 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);
>   int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
> @@ -1302,7 +1303,7 @@ 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 846ac4b23c16..7fef90f3f10b 100644
> --- a/kernel/cred.c
> +++ b/kernel/cred.c
> @@ -756,14 +756,12 @@ 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 9740b554fdb3..259c78d2f371 100644
> --- a/net/netfilter/nft_meta.c
> +++ b/net/netfilter/nft_meta.c
> @@ -625,21 +625,23 @@ 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)
> +	if (!lsmblob_is_set(&blob))
>   		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[0] is scaffolding */
> +	priv->secid = blob.secid[0];
>   	return 0;
>   }
>   
> diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
> index 2317721f3ecb..2d68416b4552 100644
> --- a/net/netfilter/xt_SECMARK.c
> +++ b/net/netfilter/xt_SECMARK.c
> @@ -45,13 +45,14 @@ 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",
> @@ -59,6 +60,8 @@ 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 d2e4ab8d1cb1..7a5a87f15736 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -881,7 +881,7 @@ 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
> @@ -905,12 +905,13 @@ 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);
>   }
>   
> @@ -932,7 +933,7 @@ 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
> @@ -954,12 +955,13 @@ 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 33563963cd45..9dc0bbfe567e 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1970,10 +1970,22 @@ 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) {
> +		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> +			continue;
> +		rc = hp->hook.secctx_to_secid(secdata, seclen,
> +					      &blob->secid[hp->lsmid->slot]);
> +		if (rc != 0)
> +			return rc;
> +	}
> +	return 0;
>   }
>   EXPORT_SYMBOL(security_secctx_to_secid);
>   
> 


^ permalink raw reply	[flat|nested] 50+ messages in thread

* [PATCH v13 07/25] LSM: Use lsmblob in security_secid_to_secctx
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (5 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 06/25] Use lsmblob in security_secctx_to_secid Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 08/25] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler
                     ` (18 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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 be called upon
to translate a secid to a string, as can occur in the
audit code.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc: netdev@vger.kernel.org
---
 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                     | 16 +++++++++++++---
 12 files changed, 71 insertions(+), 29 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index b2dad43dbf82..f9b67f585e06 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3105,10 +3105,12 @@ static void binder_transaction(struct binder_proc *proc,
 
 	if (target_node && target_node->txn_security_ctx) {
 		u32 secid;
+		struct lsmblob blob;
 		size_t added_size;
 
 		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 8cae9e4bd760..26b8cee65c64 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -495,7 +495,7 @@ 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);
@@ -1296,7 +1296,8 @@ 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 8e09f0f55b4b..e3e515158295 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1417,7 +1417,10 @@ 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;
 		}
@@ -2060,12 +2063,14 @@ 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 7566e5b1c419..04803c3099b2 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -966,6 +966,7 @@ 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)
@@ -975,7 +976,8 @@ 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 {
@@ -1218,7 +1220,10 @@ 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 {
@@ -1368,9 +1373,10 @@ 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 6cf57d5ac899..1ca97d0cb4a9 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 d8d33ef52ce0..873dbd95f84a 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -331,8 +331,10 @@ 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;
 
@@ -643,8 +645,10 @@ 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 410809c669e1..183a85412155 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 feabdfb22920..bfa7f12fde99 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -305,13 +305,17 @@ 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 7a5a87f15736..0cda17cb44a0 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -375,6 +375,7 @@ 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))
@@ -437,7 +438,8 @@ 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);
@@ -474,6 +476,7 @@ 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,
@@ -493,8 +496,10 @@ 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);
@@ -536,6 +541,7 @@ 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);
@@ -554,8 +560,10 @@ 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);
@@ -1076,6 +1084,7 @@ 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,
@@ -1130,7 +1139,8 @@ 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 3ed4fea2a2de..893301ae0131 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -86,6 +86,7 @@ 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;
@@ -98,10 +99,9 @@ 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 9dc0bbfe567e..8a04eca716b9 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1963,10 +1963,20 @@ 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) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		rc = hp->hook.secid_to_secctx(blob->secid[hp->lsmid->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] 50+ messages in thread

* [PATCH v13 08/25] LSM: Use lsmblob in security_ipc_getsecid
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (6 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 07/25] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 09/25] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
                     ` (17 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h |  7 ++++---
 kernel/auditsc.c         |  5 ++++-
 security/security.c      | 12 +++++++++---
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 26b8cee65c64..61a80afbbdba 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -466,7 +466,7 @@ 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);
@@ -1174,9 +1174,10 @@ 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 04803c3099b2..ce8bf2d8f8d2 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2285,11 +2285,14 @@ 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 8a04eca716b9..793c4ee0cf4e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1783,10 +1783,16 @@ 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) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->lsmid->slot]);
+	}
 }
 
 int security_msg_msg_alloc(struct msg_msg *msg)
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* [PATCH v13 09/25] LSM: Use lsmblob in security_task_getsecid
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (7 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 08/25] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2020-01-07 17:53     ` Stephen Smalley
  2019-12-24 23:59   ` [PATCH v13 10/25] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
                     ` (16 subsequent siblings)
  25 siblings, 1 reply; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc: linux-integrity@vger.kernel.org
---
 drivers/android/binder.c              |  4 +--
 include/linux/security.h              |  7 +++--
 kernel/audit.c                        | 11 +++----
 kernel/auditfilter.c                  |  4 +--
 kernel/auditsc.c                      | 18 ++++++++----
 net/netlabel/netlabel_unlabeled.c     |  5 +++-
 net/netlabel/netlabel_user.h          |  6 +++-
 security/integrity/ima/ima_appraise.c |  9 +++---
 security/integrity/ima/ima_main.c     | 42 +++++++++++++++------------
 security/security.c                   | 12 ++++++--
 10 files changed, 71 insertions(+), 47 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index f9b67f585e06..22fef6e130df 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3104,12 +3104,10 @@ 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;
 		size_t added_size;
 
-		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 61a80afbbdba..b6d5475f8196 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -449,7 +449,7 @@ 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);
@@ -1101,9 +1101,10 @@ 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 e3e515158295..6ee53e43c986 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2062,14 +2062,12 @@ 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)
@@ -2277,6 +2275,7 @@ int audit_set_loginuid(kuid_t loginuid)
 int audit_signal_info(int sig, struct task_struct *t)
 {
 	kuid_t uid = current_uid(), auid;
+	struct lsmblob blob;
 
 	if (auditd_test_task(t) &&
 	    (sig == SIGTERM || sig == SIGHUP ||
@@ -2287,7 +2286,9 @@ 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];
 	}
 
 	return audit_signal_info_syscall(t);
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 356db1dd276c..19cfbe716f9d 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1324,7 +1324,6 @@ 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) {
@@ -1355,8 +1354,7 @@ 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 ce8bf2d8f8d2..cccb681ad081 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;
 
@@ -641,10 +640,9 @@ 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,
@@ -2382,12 +2380,15 @@ 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);
 }
 
@@ -2403,6 +2404,7 @@ int audit_signal_info_syscall(struct task_struct *t)
 	struct audit_aux_data_pids *axp;
 	struct audit_context *ctx = audit_context();
 	kuid_t t_uid = task_uid(t);
+	struct lsmblob blob;
 
 	if (!audit_signals || audit_dummy_context())
 		return 0;
@@ -2414,7 +2416,9 @@ int audit_signal_info_syscall(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;
 	}
@@ -2435,7 +2439,9 @@ int audit_signal_info_syscall(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 0cda17cb44a0..e279b81d9545 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -1539,11 +1539,14 @@ 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 3c67afce64f1..438b5db6c714 100644
--- a/net/netlabel/netlabel_user.h
+++ b/net/netlabel/netlabel_user.h
@@ -34,7 +34,11 @@
 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 300c8d2943c5..37f540af45bb 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -48,14 +48,15 @@ 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);
-	return ima_match_policy(inode, current_cred(), secid, func, mask,
-				IMA_APPRAISE | IMA_HASH, NULL, NULL);
+	security_task_getsecid(current, &blob);
+	/* scaffolding the .secid[0] */
+	return ima_match_policy(inode, current_cred(), blob.secid[0], func,
+				mask, IMA_APPRAISE | IMA_HASH, NULL, NULL);
 }
 
 static int ima_fix_xattr(struct dentry *dentry,
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index d7e987baf127..7c4bfc051ebc 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -384,12 +384,13 @@ 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;
@@ -412,10 +413,12 @@ 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;
 
@@ -436,10 +439,11 @@ 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);
 }
@@ -548,7 +552,7 @@ 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) &&
@@ -570,9 +574,10 @@ 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);
 }
 
 /**
@@ -653,7 +658,7 @@ void process_buffer_measurement(const void *buf, int size,
 	} hash = {};
 	int violation = 0;
 	int action = 0;
-	u32 secid;
+	struct lsmblob blob;
 
 	/*
 	 * Both LSM hooks and auxilary based buffer measurements are
@@ -663,9 +668,10 @@ void process_buffer_measurement(const void *buf, int size,
 	 * buffer measurements.
 	 */
 	if (func) {
-		security_task_getsecid(current, &secid);
-		action = ima_get_action(NULL, current_cred(), secid, 0, func,
-					&pcr, &template);
+		security_task_getsecid(current, &blob);
+		/* scaffolding */
+		action = ima_get_action(NULL, current_cred(), blob.secid[0],
+					0, func, &pcr, &template);
 		if (!(action & IMA_MEASURE))
 			return;
 	}
diff --git a/security/security.c b/security/security.c
index 793c4ee0cf4e..7a170c02f8df 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1700,10 +1700,16 @@ 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) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		hp->hook.task_getsecid(p, &blob->secid[hp->lsmid->slot]);
+	}
 }
 EXPORT_SYMBOL(security_task_getsecid);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 09/25] LSM: Use lsmblob in security_task_getsecid
  2019-12-24 23:59   ` [PATCH v13 09/25] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
@ 2020-01-07 17:53     ` Stephen Smalley
  0 siblings, 0 replies; 50+ messages in thread
From: Stephen Smalley @ 2020-01-07 17:53 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul

On 12/24/19 6:59 PM, 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.
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Reviewed-by: John Johansen <john.johansen@canonical.com>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

You can drop one of your SOBs and add my Ack,

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>

> cc: linux-integrity@vger.kernel.org
> ---
>   drivers/android/binder.c              |  4 +--
>   include/linux/security.h              |  7 +++--
>   kernel/audit.c                        | 11 +++----
>   kernel/auditfilter.c                  |  4 +--
>   kernel/auditsc.c                      | 18 ++++++++----
>   net/netlabel/netlabel_unlabeled.c     |  5 +++-
>   net/netlabel/netlabel_user.h          |  6 +++-
>   security/integrity/ima/ima_appraise.c |  9 +++---
>   security/integrity/ima/ima_main.c     | 42 +++++++++++++++------------
>   security/security.c                   | 12 ++++++--
>   10 files changed, 71 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index f9b67f585e06..22fef6e130df 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -3104,12 +3104,10 @@ 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;
>   		size_t added_size;
>   
> -		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 61a80afbbdba..b6d5475f8196 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -449,7 +449,7 @@ 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);
> @@ -1101,9 +1101,10 @@ 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 e3e515158295..6ee53e43c986 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -2062,14 +2062,12 @@ 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)
> @@ -2277,6 +2275,7 @@ int audit_set_loginuid(kuid_t loginuid)
>   int audit_signal_info(int sig, struct task_struct *t)
>   {
>   	kuid_t uid = current_uid(), auid;
> +	struct lsmblob blob;
>   
>   	if (auditd_test_task(t) &&
>   	    (sig == SIGTERM || sig == SIGHUP ||
> @@ -2287,7 +2286,9 @@ 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];
>   	}
>   
>   	return audit_signal_info_syscall(t);
> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> index 356db1dd276c..19cfbe716f9d 100644
> --- a/kernel/auditfilter.c
> +++ b/kernel/auditfilter.c
> @@ -1324,7 +1324,6 @@ 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) {
> @@ -1355,8 +1354,7 @@ 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 ce8bf2d8f8d2..cccb681ad081 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;
>   
> @@ -641,10 +640,9 @@ 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,
> @@ -2382,12 +2380,15 @@ 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);
>   }
>   
> @@ -2403,6 +2404,7 @@ int audit_signal_info_syscall(struct task_struct *t)
>   	struct audit_aux_data_pids *axp;
>   	struct audit_context *ctx = audit_context();
>   	kuid_t t_uid = task_uid(t);
> +	struct lsmblob blob;
>   
>   	if (!audit_signals || audit_dummy_context())
>   		return 0;
> @@ -2414,7 +2416,9 @@ int audit_signal_info_syscall(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;
>   	}
> @@ -2435,7 +2439,9 @@ int audit_signal_info_syscall(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 0cda17cb44a0..e279b81d9545 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -1539,11 +1539,14 @@ 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 3c67afce64f1..438b5db6c714 100644
> --- a/net/netlabel/netlabel_user.h
> +++ b/net/netlabel/netlabel_user.h
> @@ -34,7 +34,11 @@
>   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 300c8d2943c5..37f540af45bb 100644
> --- a/security/integrity/ima/ima_appraise.c
> +++ b/security/integrity/ima/ima_appraise.c
> @@ -48,14 +48,15 @@ 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);
> -	return ima_match_policy(inode, current_cred(), secid, func, mask,
> -				IMA_APPRAISE | IMA_HASH, NULL, NULL);
> +	security_task_getsecid(current, &blob);
> +	/* scaffolding the .secid[0] */
> +	return ima_match_policy(inode, current_cred(), blob.secid[0], func,
> +				mask, IMA_APPRAISE | IMA_HASH, NULL, NULL);
>   }
>   
>   static int ima_fix_xattr(struct dentry *dentry,
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index d7e987baf127..7c4bfc051ebc 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -384,12 +384,13 @@ 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;
> @@ -412,10 +413,12 @@ 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;
>   
> @@ -436,10 +439,11 @@ 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);
>   }
> @@ -548,7 +552,7 @@ 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) &&
> @@ -570,9 +574,10 @@ 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);
>   }
>   
>   /**
> @@ -653,7 +658,7 @@ void process_buffer_measurement(const void *buf, int size,
>   	} hash = {};
>   	int violation = 0;
>   	int action = 0;
> -	u32 secid;
> +	struct lsmblob blob;
>   
>   	/*
>   	 * Both LSM hooks and auxilary based buffer measurements are
> @@ -663,9 +668,10 @@ void process_buffer_measurement(const void *buf, int size,
>   	 * buffer measurements.
>   	 */
>   	if (func) {
> -		security_task_getsecid(current, &secid);
> -		action = ima_get_action(NULL, current_cred(), secid, 0, func,
> -					&pcr, &template);
> +		security_task_getsecid(current, &blob);
> +		/* scaffolding */
> +		action = ima_get_action(NULL, current_cred(), blob.secid[0],
> +					0, func, &pcr, &template);
>   		if (!(action & IMA_MEASURE))
>   			return;
>   	}
> diff --git a/security/security.c b/security/security.c
> index 793c4ee0cf4e..7a170c02f8df 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1700,10 +1700,16 @@ 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) {
> +		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> +			continue;
> +		hp->hook.task_getsecid(p, &blob->secid[hp->lsmid->slot]);
> +	}
>   }
>   EXPORT_SYMBOL(security_task_getsecid);
>   
> 


^ permalink raw reply	[flat|nested] 50+ messages in thread

* [PATCH v13 10/25] LSM: Use lsmblob in security_inode_getsecid
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (8 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 09/25] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 11/25] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
                     ` (15 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
cc: linux-integrity@vger.kernel.org
---
 include/linux/security.h            |  7 ++++---
 kernel/auditsc.c                    |  6 +++++-
 security/integrity/ima/ima_policy.c |  4 +---
 security/security.c                 | 11 +++++++++--
 4 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index b6d5475f8196..e0acc09a79fe 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -409,7 +409,7 @@ 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_kernfs_init_security(struct kernfs_node *kn_dir,
@@ -924,9 +924,10 @@ 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 cccb681ad081..5752e51883d5 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1931,13 +1931,17 @@ static 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 68fe533f8a4f..c2118bb071bb 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -413,7 +413,6 @@ 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;
 
 		if (!rule->lsm[i].rule)
@@ -423,8 +422,7 @@ 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 7a170c02f8df..88e341ebab60 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1386,9 +1386,16 @@ 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) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		hp->hook.inode_getsecid(inode, &blob->secid[hp->lsmid->slot]);
+	}
 }
 
 int security_inode_copy_up(struct dentry *src, struct cred **new)
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* [PATCH v13 11/25] LSM: Use lsmblob in security_cred_getsecid
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (9 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 10/25] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 12/25] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
                     ` (14 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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 accommodate multiple possible LSM audit users.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc: linux-integrity@vger.kernel.org
---
 include/linux/security.h          |  2 +-
 kernel/audit.c                    | 19 +++++++-----------
 kernel/audit.h                    |  5 +++--
 kernel/auditsc.c                  | 33 +++++++++++--------------------
 security/integrity/ima/ima_main.c |  8 ++++----
 security/security.c               | 12 ++++++++---
 6 files changed, 36 insertions(+), 43 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index e0acc09a79fe..d12b5e828b8d 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -436,7 +436,7 @@ 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 6ee53e43c986..69b52f25038a 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -124,7 +124,7 @@ 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]
@@ -1416,23 +1416,21 @@ 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);
 		}
@@ -2275,7 +2273,6 @@ int audit_set_loginuid(kuid_t loginuid)
 int audit_signal_info(int sig, struct task_struct *t)
 {
 	kuid_t uid = current_uid(), auid;
-	struct lsmblob blob;
 
 	if (auditd_test_task(t) &&
 	    (sig == SIGTERM || sig == SIGHUP ||
@@ -2286,9 +2283,7 @@ 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);
 	}
 
 	return audit_signal_info_syscall(t);
diff --git a/kernel/audit.h b/kernel/audit.h
index 6fb7160412d4..f65f516913c6 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -9,6 +9,7 @@
 #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>
 
@@ -134,7 +135,7 @@ 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;
@@ -329,7 +330,7 @@ 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 5752e51883d5..e188fa1ade17 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;
 };
@@ -957,14 +957,14 @@ 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)
@@ -973,9 +973,8 @@ 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 {
@@ -1546,7 +1545,7 @@ 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;
 	}
@@ -1555,7 +1554,7 @@ 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) {
@@ -1733,7 +1732,7 @@ 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;
@@ -2384,15 +2383,12 @@ 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);
 }
 
@@ -2408,7 +2404,6 @@ int audit_signal_info_syscall(struct task_struct *t)
 	struct audit_aux_data_pids *axp;
 	struct audit_context *ctx = audit_context();
 	kuid_t t_uid = task_uid(t);
-	struct lsmblob blob;
 
 	if (!audit_signals || audit_dummy_context())
 		return 0;
@@ -2420,9 +2415,7 @@ int audit_signal_info_syscall(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;
 	}
@@ -2443,9 +2436,7 @@ int audit_signal_info_syscall(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 7c4bfc051ebc..c8e3e234d446 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -412,7 +412,6 @@ 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);
@@ -422,9 +421,10 @@ 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 88e341ebab60..cf87e5ef2816 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1615,10 +1615,16 @@ 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) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		hp->hook.cred_getsecid(c, &blob->secid[hp->lsmid->slot]);
+	}
 }
 EXPORT_SYMBOL(security_cred_getsecid);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* [PATCH v13 12/25] IMA: Change internal interfaces to use lsmblobs
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (10 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 11/25] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 13/25] LSM: Specify which LSM to display Casey Schaufler
                     ` (13 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc: linux-integrity@vger.kernel.org
---
 security/integrity/ima/ima.h          | 11 ++++-----
 security/integrity/ima/ima_api.c      | 10 ++++-----
 security/integrity/ima/ima_appraise.c |  5 ++---
 security/integrity/ima/ima_main.c     | 32 +++++++++++----------------
 security/integrity/ima/ima_policy.c   | 12 +++++-----
 5 files changed, 32 insertions(+), 38 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index d95b0ece7434..96b6662ea39f 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -205,9 +205,9 @@ extern const char *const func_tokens[];
 struct modsig;
 
 /* 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,
-		   struct ima_template_desc **template_desc);
+int ima_get_action(struct inode *inode, const struct cred *cred,
+		   struct lsmblob *blob, int mask, enum ima_hooks func,
+		   int *pcr, struct ima_template_desc **template_desc);
 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,
@@ -232,8 +232,9 @@ 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,
 		     struct ima_template_desc **template_desc);
 void ima_init_policy(void);
 void ima_update_policy(void);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 610759fe63b8..1ab769fa7df6 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -163,7 +163,7 @@ 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: LSM data of the task being validated
  * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC,
  *        MAY_APPEND)
  * @func: caller identifier
@@ -181,15 +181,15 @@ 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,
-		   struct ima_template_desc **template_desc)
+int ima_get_action(struct inode *inode, const struct cred *cred,
+		   struct lsmblob *blob, int mask, enum ima_hooks func,
+		   int *pcr, struct ima_template_desc **template_desc)
 {
 	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,
 				template_desc);
 }
 
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 37f540af45bb..01c755a242ac 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -54,9 +54,8 @@ int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
 		return 0;
 
 	security_task_getsecid(current, &blob);
-	/* scaffolding the .secid[0] */
-	return ima_match_policy(inode, current_cred(), blob.secid[0], func,
-				mask, IMA_APPRAISE | IMA_HASH, NULL, NULL);
+	return ima_match_policy(inode, current_cred(), &blob, func, mask,
+				IMA_APPRAISE | IMA_HASH, NULL, NULL);
 }
 
 static int ima_fix_xattr(struct dentry *dentry,
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index c8e3e234d446..86cc1419587e 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -190,8 +190,8 @@ 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;
@@ -214,7 +214,7 @@ 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,
 				&template_desc);
 	violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
 			   (ima_policy_flag & IMA_MEASURE));
@@ -388,8 +388,7 @@ 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);
 	}
 
@@ -415,16 +414,14 @@ 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);
 }
 
 /**
@@ -442,8 +439,7 @@ 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);
 }
@@ -575,9 +571,8 @@ 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);
 }
 
 /**
@@ -669,9 +664,8 @@ void process_buffer_measurement(const void *buf, int size,
 	 */
 	if (func) {
 		security_task_getsecid(current, &blob);
-		/* scaffolding */
-		action = ima_get_action(NULL, current_cred(), blob.secid[0],
-					0, func, &pcr, &template);
+		action = ima_get_action(NULL, current_cred(), &blob, 0, func,
+					&pcr, &template);
 		if (!(action & IMA_MEASURE))
 			return;
 	}
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index c2118bb071bb..1c617ae74558 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -368,7 +368,7 @@ int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
  * 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;
@@ -431,7 +431,6 @@ 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,
@@ -475,7 +474,7 @@ 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
@@ -488,8 +487,9 @@ 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_template_desc **template_desc)
 {
 	struct ima_rule_entry *entry;
@@ -504,7 +504,7 @@ 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] 50+ messages in thread

* [PATCH v13 13/25] LSM: Specify which LSM to display
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (11 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 12/25] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2020-01-07 19:02     ` Stephen Smalley
  2019-12-24 23:59   ` [PATCH v13 14/25] LSM: Ensure the correct LSM context releaser Casey Schaufler
                     ` (12 subsequent siblings)
  25 siblings, 1 reply; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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 the procfs attr directory for
controlling which LSM security information is displayed for a
process. A process can only read or write its own display value.

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. A helper function lsm_task_display() is
provided to get the display slot for a task_struct.

Setting the "display" requires that all security modules using
setprocattr hooks allow the action. Each security module is
responsible for defining its policy.

AppArmor hook provided by John Johansen <john.johansen@canonical.com>
SELinux hook provided by Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 fs/proc/base.c                       |   1 +
 include/linux/lsm_hooks.h            |  15 +++
 security/apparmor/include/apparmor.h |   3 +-
 security/apparmor/lsm.c              |  32 +++++
 security/security.c                  | 168 ++++++++++++++++++++++++---
 security/selinux/hooks.c             |  11 ++
 security/selinux/include/classmap.h  |   2 +-
 security/smack/smack_lsm.c           |   7 ++
 8 files changed, 220 insertions(+), 19 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index ebea9501afb8..950c200cb9ad 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2652,6 +2652,7 @@ 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/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 7eb808cde051..2bf82e1cf347 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -2186,4 +2186,19 @@ static inline void security_delete_hooks(struct security_hook_list *hooks,
 
 extern int lsm_inode_alloc(struct inode *inode);
 
+/**
+ * lsm_task_display - the "display" LSM for this task
+ * @task: The task to report on
+ *
+ * Returns the task's display LSM slot.
+ */
+static inline int lsm_task_display(struct task_struct *task)
+{
+	int *display = task->security;
+
+	if (display)
+		return *display;
+	return LSMBLOB_INVALID;
+}
+
 #endif /* ! __LINUX_LSM_HOOKS_H */
diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h
index 1fbabdb565a8..b1622fcb4394 100644
--- a/security/apparmor/include/apparmor.h
+++ b/security/apparmor/include/apparmor.h
@@ -28,8 +28,9 @@
 #define AA_CLASS_SIGNAL		10
 #define AA_CLASS_NET		14
 #define AA_CLASS_LABEL		16
+#define AA_CLASS_DISPLAY_LSM	17
 
-#define AA_CLASS_LAST		AA_CLASS_LABEL
+#define AA_CLASS_LAST		AA_CLASS_DISPLAY_LSM
 
 /* Control parameters settable through module/boot flags */
 extern enum audit_mode aa_g_audit;
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 146d75e5e021..16b992235c11 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -612,6 +612,25 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
 	return error;
 }
 
+
+static int profile_display_lsm(struct aa_profile *profile,
+			       struct common_audit_data *sa)
+{
+	struct aa_perms perms = { };
+	unsigned int state;
+
+	state = PROFILE_MEDIATES(profile, AA_CLASS_DISPLAY_LSM);
+	if (state) {
+		aa_compute_perms(profile->policy.dfa, state, &perms);
+		aa_apply_modes_to_perms(profile, &perms);
+		aad(sa)->label = &profile->label;
+
+		return aa_check_perms(profile, &perms, AA_MAY_WRITE, sa, NULL);
+	}
+
+	return 0;
+}
+
 static int apparmor_setprocattr(const char *name, void *value,
 				size_t size)
 {
@@ -623,6 +642,19 @@ static int apparmor_setprocattr(const char *name, void *value,
 	if (size == 0)
 		return -EINVAL;
 
+	/* LSM infrastructure does actual setting of display if allowed */
+	if (!strcmp(name, "display")) {
+		struct aa_profile *profile;
+		struct aa_label *label;
+
+		aad(&sa)->info = "set display lsm";
+		label = begin_current_label_crit_section();
+		error = fn_for_each_confined(label, profile,
+					     profile_display_lsm(profile, &sa));
+		end_current_label_crit_section(label);
+		return error;
+	}
+
 	/* AppArmor requires that the buffer must be null terminated atm */
 	if (args[size - 1] != '\0') {
 		/* null terminate */
diff --git a/security/security.c b/security/security.c
index cf87e5ef2816..aaf6db47dd8a 100644
--- a/security/security.c
+++ b/security/security.c
@@ -27,6 +27,7 @@
 #include <linux/backing-dev.h>
 #include <linux/string.h>
 #include <linux/msg.h>
+#include <linux/binfmts.h>
 #include <net/flow.h>
 #include <net/sock.h>
 
@@ -43,7 +44,14 @@ 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;
+
+/*
+ * The task blob includes the "display" slot used for
+ * chosing which module presents contexts.
+ */
+static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init = {
+	.lbs_task = sizeof(int),
+};
 
 /* Boot-time LSM user choice */
 static __initdata const char *chosen_lsm_order;
@@ -438,8 +446,10 @@ static int lsm_append(const char *new, char **result)
 
 /*
  * Current index to use while initializing the lsmblob secid list.
+ * Pointers to the LSM id structures for local use.
  */
 static int lsm_slot __lsm_ro_after_init;
+static struct lsm_id *lsm_slotlist[LSMBLOB_ENTRIES];
 
 /**
  * security_add_hooks - Add a modules hooks to the hook lists.
@@ -459,6 +469,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
 	if (lsmid->slot == LSMBLOB_NEEDED) {
 		if (lsm_slot >= LSMBLOB_ENTRIES)
 			panic("%s Too many LSMs registered.\n", __func__);
+		lsm_slotlist[lsm_slot] = lsmid;
 		lsmid->slot = lsm_slot++;
 		init_debug("%s assigned lsmblob slot %d\n", lsmid->lsm,
 			   lsmid->slot);
@@ -588,6 +599,8 @@ 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;
@@ -596,6 +609,15 @@ 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;
 }
 
@@ -1551,14 +1573,26 @@ 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;
+	}
+
+	if (odisplay) {
+		ndisplay = task->security;
+		if (ndisplay)
+			*ndisplay = *odisplay;
+	}
+
+	return 0;
 }
 
 void security_task_free(struct task_struct *task)
@@ -1955,23 +1989,110 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
 				char **value)
 {
 	struct security_hook_list *hp;
+	int display = lsm_task_display(current);
+	int slot = 0;
+
+	if (!strcmp(name, "display")) {
+		/*
+		 * lsm_slot will be 0 if there are no displaying modules.
+		 */
+		if (lsm_slot == 0)
+			return -EINVAL;
+
+		/*
+		 * Only allow getting the current process' display.
+		 * There are too few reasons to get another process'
+		 * display and too many LSM policy issues.
+		 */
+		if (current != p)
+			return -EINVAL;
+
+		display = lsm_task_display(p);
+		if (display != LSMBLOB_INVALID)
+			slot = display;
+		*value = kstrdup(lsm_slotlist[slot]->lsm, GFP_KERNEL);
+		if (*value)
+			return strlen(*value);
+		return -ENOMEM;
+	}
 
 	hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
 		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
 			continue;
+		if (lsm == NULL && display != LSMBLOB_INVALID &&
+		    display != hp->lsmid->slot)
+			continue;
 		return hp->hook.getprocattr(p, name, value);
 	}
 	return -EINVAL;
 }
 
+/**
+ * security_setprocattr - Set process attributes via /proc
+ * @lsm: name of module involved, or NULL
+ * @name: name of the attribute
+ * @value: value to set the attribute to
+ * @size: size of the value
+ *
+ * Set the process attribute for the specified security module
+ * to the specified value. Note that this can only be used to set
+ * the process attributes for the current, or "self" process.
+ * The /proc code has already done this check.
+ *
+ * Returns 0 on success, an appropriate code otherwise.
+ */
 int security_setprocattr(const char *lsm, const char *name, void *value,
 			 size_t size)
 {
 	struct security_hook_list *hp;
+	char *termed;
+	char *copy;
+	int *display = current->security;
+	int rc = -EINVAL;
+	int slot = 0;
+
+	if (!strcmp(name, "display")) {
+		/*
+		 * Change the "display" value only if all the security
+		 * modules that support setting a procattr allow it.
+		 * It is assumed that all such security modules will be
+		 * cooperative.
+		 */
+		if (size == 0)
+			return -EINVAL;
+
+		hlist_for_each_entry(hp, &security_hook_heads.setprocattr,
+				     list) {
+			rc = hp->hook.setprocattr(name, value, size);
+			if (rc < 0)
+				return rc;
+		}
+
+		rc = -EINVAL;
+
+		copy = kmemdup_nul(value, size, GFP_KERNEL);
+		if (copy == NULL)
+			return -ENOMEM;
+
+		termed = strsep(&copy, " \n");
+
+		for (slot = 0; slot < lsm_slot; slot++)
+			if (!strcmp(termed, lsm_slotlist[slot]->lsm)) {
+				*display = lsm_slotlist[slot]->slot;
+				rc = size;
+				break;
+			}
+
+		kfree(copy);
+		return rc;
+	}
 
 	hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
 		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
 			continue;
+		if (lsm == NULL && *display != LSMBLOB_INVALID &&
+		    *display != hp->lsmid->slot)
+			continue;
 		return hp->hook.setprocattr(name, value, size);
 	}
 	return -EINVAL;
@@ -1991,15 +2112,15 @@ 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 = lsm_task_display(current);
 
 	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
 		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
 			continue;
-		rc = hp->hook.secid_to_secctx(blob->secid[hp->lsmid->slot],
-					      secdata, seclen);
-		if (rc != 0)
-			return rc;
+		if (display == LSMBLOB_INVALID || display == hp->lsmid->slot)
+			return hp->hook.secid_to_secctx(
+					blob->secid[hp->lsmid->slot],
+					secdata, seclen);
 	}
 	return 0;
 }
@@ -2009,16 +2130,15 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
 			     struct lsmblob *blob)
 {
 	struct security_hook_list *hp;
-	int rc;
+	int display = lsm_task_display(current);
 
 	lsmblob_init(blob, 0);
 	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
 		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
 			continue;
-		rc = hp->hook.secctx_to_secid(secdata, seclen,
-					      &blob->secid[hp->lsmid->slot]);
-		if (rc != 0)
-			return rc;
+		if (display == LSMBLOB_INVALID || display == hp->lsmid->slot)
+			return hp->hook.secctx_to_secid(secdata, seclen,
+						&blob->secid[hp->lsmid->slot]);
 	}
 	return 0;
 }
@@ -2026,7 +2146,14 @@ 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 = lsm_task_display(current);
+
+	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
+		if (display == LSMBLOB_INVALID || display == hp->lsmid->slot) {
+			hp->hook.release_secctx(secdata, seclen);
+			return;
+		}
 }
 EXPORT_SYMBOL(security_release_secctx);
 
@@ -2151,8 +2278,15 @@ 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 = lsm_task_display(current);
+	struct security_hook_list *hp;
+
+	hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_stream,
+			     list)
+		if (display == LSMBLOB_INVALID || display == hp->lsmid->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,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 97f2ee6e4080..b8501ca3c8f3 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6323,6 +6323,17 @@ static int selinux_setprocattr(const char *name, void *value, size_t size)
 	/*
 	 * Basic control over ability to set these attributes at all.
 	 */
+
+	/*
+	 * For setting display, we only perform a permission check;
+	 * the actual update to the display value is handled by the
+	 * LSM framework.
+	 */
+	if (!strcmp(name, "display"))
+		return avc_has_perm(&selinux_state,
+				    mysid, mysid, SECCLASS_PROCESS2,
+				    PROCESS2__SETDISPLAY, NULL);
+
 	if (!strcmp(name, "exec"))
 		error = avc_has_perm(&selinux_state,
 				     mysid, mysid, SECCLASS_PROCESS,
diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index 7db24855e12d..323da8a38c43 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -52,7 +52,7 @@ struct security_class_mapping secclass_map[] = {
 	    "execmem", "execstack", "execheap", "setkeycreate",
 	    "setsockcreate", "getrlimit", NULL } },
 	{ "process2",
-	  { "nnp_transition", "nosuid_transition", NULL } },
+	  { "nnp_transition", "nosuid_transition", "setdisplay", NULL } },
 	{ "system",
 	  { "ipc_info", "syslog_read", "syslog_mod",
 	    "syslog_console", "module_request", "module_load", NULL } },
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 82cbb3eeec76..9737ead06b39 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3518,6 +3518,13 @@ static int smack_setprocattr(const char *name, void *value, size_t size)
 	struct smack_known_list_elem *sklep;
 	int rc;
 
+	/*
+	 * Allow the /proc/.../attr/current and SO_PEERSEC "display"
+	 * to be reset at will.
+	 */
+	if (strcmp(name, "display") == 0)
+		return 0;
+
 	if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel))
 		return -EPERM;
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 13/25] LSM: Specify which LSM to display
  2019-12-24 23:59   ` [PATCH v13 13/25] LSM: Specify which LSM to display Casey Schaufler
@ 2020-01-07 19:02     ` Stephen Smalley
  0 siblings, 0 replies; 50+ messages in thread
From: Stephen Smalley @ 2020-01-07 19:02 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul

On 12/24/19 6:59 PM, Casey Schaufler wrote:
> Create a new entry "display" in the procfs attr directory for
> controlling which LSM security information is displayed for a
> process. A process can only read or write its own display value.
> 
> 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. A helper function lsm_task_display() is
> provided to get the display slot for a task_struct.
> 
> Setting the "display" requires that all security modules using
> setprocattr hooks allow the action. Each security module is
> responsible for defining its policy.
> 
> AppArmor hook provided by John Johansen <john.johansen@canonical.com>
> SELinux hook provided by Stephen Smalley <sds@tycho.nsa.gov>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---
>   fs/proc/base.c                       |   1 +
>   include/linux/lsm_hooks.h            |  15 +++
>   security/apparmor/include/apparmor.h |   3 +-
>   security/apparmor/lsm.c              |  32 +++++
>   security/security.c                  | 168 ++++++++++++++++++++++++---
>   security/selinux/hooks.c             |  11 ++
>   security/selinux/include/classmap.h  |   2 +-
>   security/smack/smack_lsm.c           |   7 ++
>   8 files changed, 220 insertions(+), 19 deletions(-)
> 
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index ebea9501afb8..950c200cb9ad 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -2652,6 +2652,7 @@ 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/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index 7eb808cde051..2bf82e1cf347 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -2186,4 +2186,19 @@ static inline void security_delete_hooks(struct security_hook_list *hooks,
>   
>   extern int lsm_inode_alloc(struct inode *inode);
>   
> +/**
> + * lsm_task_display - the "display" LSM for this task
> + * @task: The task to report on
> + *
> + * Returns the task's display LSM slot.
> + */
> +static inline int lsm_task_display(struct task_struct *task)
> +{
> +	int *display = task->security;
> +
> +	if (display)
> +		return *display;
> +	return LSMBLOB_INVALID;
> +}
> +
>   #endif /* ! __LINUX_LSM_HOOKS_H */
> diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h
> index 1fbabdb565a8..b1622fcb4394 100644
> --- a/security/apparmor/include/apparmor.h
> +++ b/security/apparmor/include/apparmor.h
> @@ -28,8 +28,9 @@
>   #define AA_CLASS_SIGNAL		10
>   #define AA_CLASS_NET		14
>   #define AA_CLASS_LABEL		16
> +#define AA_CLASS_DISPLAY_LSM	17
>   
> -#define AA_CLASS_LAST		AA_CLASS_LABEL
> +#define AA_CLASS_LAST		AA_CLASS_DISPLAY_LSM
>   
>   /* Control parameters settable through module/boot flags */
>   extern enum audit_mode aa_g_audit;
> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
> index 146d75e5e021..16b992235c11 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -612,6 +612,25 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
>   	return error;
>   }
>   
> +
> +static int profile_display_lsm(struct aa_profile *profile,
> +			       struct common_audit_data *sa)
> +{
> +	struct aa_perms perms = { };
> +	unsigned int state;
> +
> +	state = PROFILE_MEDIATES(profile, AA_CLASS_DISPLAY_LSM);
> +	if (state) {
> +		aa_compute_perms(profile->policy.dfa, state, &perms);
> +		aa_apply_modes_to_perms(profile, &perms);
> +		aad(sa)->label = &profile->label;
> +
> +		return aa_check_perms(profile, &perms, AA_MAY_WRITE, sa, NULL);
> +	}
> +
> +	return 0;
> +}
> +
>   static int apparmor_setprocattr(const char *name, void *value,
>   				size_t size)
>   {
> @@ -623,6 +642,19 @@ static int apparmor_setprocattr(const char *name, void *value,
>   	if (size == 0)
>   		return -EINVAL;
>   
> +	/* LSM infrastructure does actual setting of display if allowed */
> +	if (!strcmp(name, "display")) {
> +		struct aa_profile *profile;
> +		struct aa_label *label;
> +
> +		aad(&sa)->info = "set display lsm";
> +		label = begin_current_label_crit_section();
> +		error = fn_for_each_confined(label, profile,
> +					     profile_display_lsm(profile, &sa));
> +		end_current_label_crit_section(label);
> +		return error;
> +	}
> +
>   	/* AppArmor requires that the buffer must be null terminated atm */
>   	if (args[size - 1] != '\0') {
>   		/* null terminate */
> diff --git a/security/security.c b/security/security.c
> index cf87e5ef2816..aaf6db47dd8a 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -27,6 +27,7 @@
>   #include <linux/backing-dev.h>
>   #include <linux/string.h>
>   #include <linux/msg.h>
> +#include <linux/binfmts.h>

What's this #include for?

Otherwise,
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>

>   #include <net/flow.h>
>   #include <net/sock.h>
>   
> @@ -43,7 +44,14 @@ 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;
> +
> +/*
> + * The task blob includes the "display" slot used for
> + * chosing which module presents contexts.
> + */
> +static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init = {
> +	.lbs_task = sizeof(int),
> +};
>   
>   /* Boot-time LSM user choice */
>   static __initdata const char *chosen_lsm_order;
> @@ -438,8 +446,10 @@ static int lsm_append(const char *new, char **result)
>   
>   /*
>    * Current index to use while initializing the lsmblob secid list.
> + * Pointers to the LSM id structures for local use.
>    */
>   static int lsm_slot __lsm_ro_after_init;
> +static struct lsm_id *lsm_slotlist[LSMBLOB_ENTRIES];
>   
>   /**
>    * security_add_hooks - Add a modules hooks to the hook lists.
> @@ -459,6 +469,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
>   	if (lsmid->slot == LSMBLOB_NEEDED) {
>   		if (lsm_slot >= LSMBLOB_ENTRIES)
>   			panic("%s Too many LSMs registered.\n", __func__);
> +		lsm_slotlist[lsm_slot] = lsmid;
>   		lsmid->slot = lsm_slot++;
>   		init_debug("%s assigned lsmblob slot %d\n", lsmid->lsm,
>   			   lsmid->slot);
> @@ -588,6 +599,8 @@ 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;
> @@ -596,6 +609,15 @@ 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;
>   }
>   
> @@ -1551,14 +1573,26 @@ 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;
> +	}
> +
> +	if (odisplay) {
> +		ndisplay = task->security;
> +		if (ndisplay)
> +			*ndisplay = *odisplay;
> +	}
> +
> +	return 0;
>   }
>   
>   void security_task_free(struct task_struct *task)
> @@ -1955,23 +1989,110 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
>   				char **value)
>   {
>   	struct security_hook_list *hp;
> +	int display = lsm_task_display(current);
> +	int slot = 0;
> +
> +	if (!strcmp(name, "display")) {
> +		/*
> +		 * lsm_slot will be 0 if there are no displaying modules.
> +		 */
> +		if (lsm_slot == 0)
> +			return -EINVAL;
> +
> +		/*
> +		 * Only allow getting the current process' display.
> +		 * There are too few reasons to get another process'
> +		 * display and too many LSM policy issues.
> +		 */
> +		if (current != p)
> +			return -EINVAL;
> +
> +		display = lsm_task_display(p);
> +		if (display != LSMBLOB_INVALID)
> +			slot = display;
> +		*value = kstrdup(lsm_slotlist[slot]->lsm, GFP_KERNEL);
> +		if (*value)
> +			return strlen(*value);
> +		return -ENOMEM;
> +	}
>   
>   	hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
>   		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
>   			continue;
> +		if (lsm == NULL && display != LSMBLOB_INVALID &&
> +		    display != hp->lsmid->slot)
> +			continue;
>   		return hp->hook.getprocattr(p, name, value);
>   	}
>   	return -EINVAL;
>   }
>   
> +/**
> + * security_setprocattr - Set process attributes via /proc
> + * @lsm: name of module involved, or NULL
> + * @name: name of the attribute
> + * @value: value to set the attribute to
> + * @size: size of the value
> + *
> + * Set the process attribute for the specified security module
> + * to the specified value. Note that this can only be used to set
> + * the process attributes for the current, or "self" process.
> + * The /proc code has already done this check.
> + *
> + * Returns 0 on success, an appropriate code otherwise.
> + */
>   int security_setprocattr(const char *lsm, const char *name, void *value,
>   			 size_t size)
>   {
>   	struct security_hook_list *hp;
> +	char *termed;
> +	char *copy;
> +	int *display = current->security;
> +	int rc = -EINVAL;
> +	int slot = 0;
> +
> +	if (!strcmp(name, "display")) {
> +		/*
> +		 * Change the "display" value only if all the security
> +		 * modules that support setting a procattr allow it.
> +		 * It is assumed that all such security modules will be
> +		 * cooperative.
> +		 */
> +		if (size == 0)
> +			return -EINVAL;
> +
> +		hlist_for_each_entry(hp, &security_hook_heads.setprocattr,
> +				     list) {
> +			rc = hp->hook.setprocattr(name, value, size);
> +			if (rc < 0)
> +				return rc;
> +		}
> +
> +		rc = -EINVAL;
> +
> +		copy = kmemdup_nul(value, size, GFP_KERNEL);
> +		if (copy == NULL)
> +			return -ENOMEM;
> +
> +		termed = strsep(&copy, " \n");
> +
> +		for (slot = 0; slot < lsm_slot; slot++)
> +			if (!strcmp(termed, lsm_slotlist[slot]->lsm)) {
> +				*display = lsm_slotlist[slot]->slot;
> +				rc = size;
> +				break;
> +			}
> +
> +		kfree(copy);
> +		return rc;
> +	}
>   
>   	hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
>   		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
>   			continue;
> +		if (lsm == NULL && *display != LSMBLOB_INVALID &&
> +		    *display != hp->lsmid->slot)
> +			continue;
>   		return hp->hook.setprocattr(name, value, size);
>   	}
>   	return -EINVAL;
> @@ -1991,15 +2112,15 @@ 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 = lsm_task_display(current);
>   
>   	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
>   		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
>   			continue;
> -		rc = hp->hook.secid_to_secctx(blob->secid[hp->lsmid->slot],
> -					      secdata, seclen);
> -		if (rc != 0)
> -			return rc;
> +		if (display == LSMBLOB_INVALID || display == hp->lsmid->slot)
> +			return hp->hook.secid_to_secctx(
> +					blob->secid[hp->lsmid->slot],
> +					secdata, seclen);
>   	}
>   	return 0;
>   }
> @@ -2009,16 +2130,15 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
>   			     struct lsmblob *blob)
>   {
>   	struct security_hook_list *hp;
> -	int rc;
> +	int display = lsm_task_display(current);
>   
>   	lsmblob_init(blob, 0);
>   	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
>   		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
>   			continue;
> -		rc = hp->hook.secctx_to_secid(secdata, seclen,
> -					      &blob->secid[hp->lsmid->slot]);
> -		if (rc != 0)
> -			return rc;
> +		if (display == LSMBLOB_INVALID || display == hp->lsmid->slot)
> +			return hp->hook.secctx_to_secid(secdata, seclen,
> +						&blob->secid[hp->lsmid->slot]);
>   	}
>   	return 0;
>   }
> @@ -2026,7 +2146,14 @@ 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 = lsm_task_display(current);
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
> +		if (display == LSMBLOB_INVALID || display == hp->lsmid->slot) {
> +			hp->hook.release_secctx(secdata, seclen);
> +			return;
> +		}
>   }
>   EXPORT_SYMBOL(security_release_secctx);
>   
> @@ -2151,8 +2278,15 @@ 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 = lsm_task_display(current);
> +	struct security_hook_list *hp;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_stream,
> +			     list)
> +		if (display == LSMBLOB_INVALID || display == hp->lsmid->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,
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 97f2ee6e4080..b8501ca3c8f3 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -6323,6 +6323,17 @@ static int selinux_setprocattr(const char *name, void *value, size_t size)
>   	/*
>   	 * Basic control over ability to set these attributes at all.
>   	 */
> +
> +	/*
> +	 * For setting display, we only perform a permission check;
> +	 * the actual update to the display value is handled by the
> +	 * LSM framework.
> +	 */
> +	if (!strcmp(name, "display"))
> +		return avc_has_perm(&selinux_state,
> +				    mysid, mysid, SECCLASS_PROCESS2,
> +				    PROCESS2__SETDISPLAY, NULL);
> +
>   	if (!strcmp(name, "exec"))
>   		error = avc_has_perm(&selinux_state,
>   				     mysid, mysid, SECCLASS_PROCESS,
> diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
> index 7db24855e12d..323da8a38c43 100644
> --- a/security/selinux/include/classmap.h
> +++ b/security/selinux/include/classmap.h
> @@ -52,7 +52,7 @@ struct security_class_mapping secclass_map[] = {
>   	    "execmem", "execstack", "execheap", "setkeycreate",
>   	    "setsockcreate", "getrlimit", NULL } },
>   	{ "process2",
> -	  { "nnp_transition", "nosuid_transition", NULL } },
> +	  { "nnp_transition", "nosuid_transition", "setdisplay", NULL } },
>   	{ "system",
>   	  { "ipc_info", "syslog_read", "syslog_mod",
>   	    "syslog_console", "module_request", "module_load", NULL } },
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 82cbb3eeec76..9737ead06b39 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -3518,6 +3518,13 @@ static int smack_setprocattr(const char *name, void *value, size_t size)
>   	struct smack_known_list_elem *sklep;
>   	int rc;
>   
> +	/*
> +	 * Allow the /proc/.../attr/current and SO_PEERSEC "display"
> +	 * to be reset at will.
> +	 */
> +	if (strcmp(name, "display") == 0)
> +		return 0;
> +
>   	if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel))
>   		return -EPERM;
>   
> 


^ permalink raw reply	[flat|nested] 50+ messages in thread

* [PATCH v13 14/25] LSM: Ensure the correct LSM context releaser
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (12 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 13/25] LSM: Specify which LSM to display Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2020-01-07 19:16     ` Stephen Smalley
  2019-12-24 23:59   ` [PATCH v13 15/25] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
                     ` (11 subsequent siblings)
  25 siblings, 1 reply; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc: linux-integrity@vger.kernel.org
cc: netdev@vger.kernel.org
---
 drivers/android/binder.c                | 10 ++++---
 fs/ceph/xattr.c                         |  6 ++++-
 fs/nfs/nfs4proc.c                       |  8 ++++--
 fs/nfsd/nfs4xdr.c                       |  7 +++--
 include/linux/security.h                | 35 +++++++++++++++++++++++--
 include/net/scm.h                       |  5 +++-
 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                     | 11 ++++----
 15 files changed, 121 insertions(+), 35 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 22fef6e130df..7559c5d5eea4 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2861,6 +2861,7 @@ 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;
@@ -3157,7 +3158,8 @@ static void binder_transaction(struct binder_proc *proc,
 			t->security_ctx = 0;
 			WARN_ON(1);
 		}
-		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;
@@ -3490,8 +3492,10 @@ static void binder_transaction(struct binder_proc *proc,
 	binder_alloc_free_buf(&target_proc->alloc, t->buffer);
 err_binder_alloc_buf_failed:
 err_bad_extra_size:
-	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/ceph/xattr.c b/fs/ceph/xattr.c
index cb18ee637cb7..ad501b5cad2c 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -1271,12 +1271,16 @@ int ceph_security_init_secctx(struct dentry *dentry, umode_t mode,
 
 void ceph_release_acl_sec_ctx(struct ceph_acl_sec_ctx *as_ctx)
 {
+#ifdef CONFIG_CEPH_FS_SECURITY_LABEL
+	struct lsmcontext scaff; /* scaffolding */
+#endif
 #ifdef CONFIG_CEPH_FS_POSIX_ACL
 	posix_acl_release(as_ctx->acl);
 	posix_acl_release(as_ctx->default_acl);
 #endif
 #ifdef CONFIG_CEPH_FS_SECURITY_LABEL
-	security_release_secctx(as_ctx->sec_ctx, as_ctx->sec_ctxlen);
+	lsmcontext_init(&scaff, as_ctx->sec_ctx, as_ctx->sec_ctxlen, 0);
+	security_release_secctx(&scaff);
 #endif
 	if (as_ctx->pagelist)
 		ceph_pagelist_release(as_ctx->pagelist);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 76d37161409a..a30e36654c57 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -130,8 +130,12 @@ 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 d2dc4c0e22e8..e20011281915 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2421,6 +2421,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 	int err;
 	struct nfs4_acl *acl = NULL;
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	struct lsmcontext scaff; /* scaffolding */
 	void *context = NULL;
 	int contextlen;
 #endif
@@ -2923,8 +2924,10 @@ 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 d12b5e828b8d..c040c959b413 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -128,6 +128,37 @@ enum lockdown_reason {
 	LOCKDOWN_CONFIDENTIALITY_MAX,
 };
 
+/*
+ * 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;
+	cp->len = size;
+}
+
 /*
  * Data exported by the security modules
  *
@@ -498,7 +529,7 @@ 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);
 int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
@@ -1312,7 +1343,7 @@ 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..30ba801c91bd 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 +103,9 @@ 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);
+			/*scaffolding*/
+			lsmcontext_init(&context, secdata, seclen, 0);
+			security_release_secctx(&context);
 		}
 	}
 }
diff --git a/kernel/audit.c b/kernel/audit.c
index 69b52f25038a..3305c4af43a8 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1180,6 +1180,7 @@ 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)
@@ -1424,15 +1425,18 @@ 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);
@@ -2061,6 +2065,7 @@ 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))
@@ -2074,7 +2079,8 @@ 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 e188fa1ade17..9774d9947128 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -962,6 +962,7 @@ 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;
@@ -979,7 +980,8 @@ 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=");
@@ -1192,6 +1194,7 @@ 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;
 
@@ -1225,7 +1228,8 @@ 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) {
@@ -1371,6 +1375,7 @@ 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)) {
@@ -1379,7 +1384,8 @@ 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 1ca97d0cb4a9..96d56a30ecca 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 873dbd95f84a..2f233f40c926 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -332,6 +332,7 @@ 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);
@@ -349,7 +350,8 @@ 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 183a85412155..8601fcb99f7a 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 bfa7f12fde99..cc3ef03ee198 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -395,6 +395,7 @@ 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;
 
@@ -625,8 +626,10 @@ 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:
@@ -634,8 +637,10 @@ 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 e279b81d9545..288c005b44c7 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -373,6 +373,7 @@ 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;
@@ -443,7 +444,9 @@ 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);
@@ -474,6 +477,7 @@ 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;
@@ -502,7 +506,9 @@ 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);
@@ -539,6 +545,7 @@ 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;
@@ -566,7 +573,8 @@ 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);
@@ -1080,6 +1088,7 @@ 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;
@@ -1147,7 +1156,9 @@ 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 893301ae0131..ef139d8ae7cd 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -84,6 +84,7 @@ 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;
@@ -103,7 +104,8 @@ 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 aaf6db47dd8a..6be4be40127e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2144,16 +2144,17 @@ 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 = lsm_task_display(current);
 
 	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
-		if (display == LSMBLOB_INVALID || display == hp->lsmid->slot) {
-			hp->hook.release_secctx(secdata, seclen);
-			return;
+		if (cp->slot == hp->lsmid->slot) {
+			hp->hook.release_secctx(cp->context, cp->len);
+			break;
 		}
+
+	memset(cp, 0, sizeof(*cp));
 }
 EXPORT_SYMBOL(security_release_secctx);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 14/25] LSM: Ensure the correct LSM context releaser
  2019-12-24 23:59   ` [PATCH v13 14/25] LSM: Ensure the correct LSM context releaser Casey Schaufler
@ 2020-01-07 19:16     ` Stephen Smalley
  0 siblings, 0 replies; 50+ messages in thread
From: Stephen Smalley @ 2020-01-07 19:16 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul

On 12/24/19 6:59 PM, 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.
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Reviewed-by: John Johansen <john.johansen@canonical.com>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> cc: linux-integrity@vger.kernel.org
> cc: netdev@vger.kernel.org
> ---
>   drivers/android/binder.c                | 10 ++++---
>   fs/ceph/xattr.c                         |  6 ++++-
>   fs/nfs/nfs4proc.c                       |  8 ++++--
>   fs/nfsd/nfs4xdr.c                       |  7 +++--
>   include/linux/security.h                | 35 +++++++++++++++++++++++--
>   include/net/scm.h                       |  5 +++-
>   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                     | 11 ++++----
>   15 files changed, 121 insertions(+), 35 deletions(-)
> 


> diff --git a/include/linux/security.h b/include/linux/security.h
> index d12b5e828b8d..c040c959b413 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -128,6 +128,37 @@ enum lockdown_reason {
>   	LOCKDOWN_CONFIDENTIALITY_MAX,
>   };
>   
> +/*
> + * 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.

Still present after the entire series is applied, with one residual user 
in ceph.  Intentional or an oversight?

Otherwise,
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>

> + */
> +static inline void lsmcontext_init(struct lsmcontext *cp, char *context,
> +				   u32 size, int slot)
> +{
> +	cp->slot = slot;
> +	cp->context = context;
> +	cp->len = size;
> +}
> +
>   /*
>    * Data exported by the security modules
>    *



^ permalink raw reply	[flat|nested] 50+ messages in thread

* [PATCH v13 15/25] LSM: Use lsmcontext in security_secid_to_secctx
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (13 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 14/25] LSM: Ensure the correct LSM context releaser Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2020-01-06 16:15     ` Stephen Smalley
  2019-12-24 23:59   ` [PATCH v13 16/25] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
                     ` (10 subsequent siblings)
  25 siblings, 1 reply; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc: netdev@vger.kernel.org
---
 drivers/android/binder.c                | 26 +++++++---------
 include/linux/security.h                |  4 +--
 include/net/scm.h                       | 10 ++-----
 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                     | 10 +++++--
 12 files changed, 74 insertions(+), 116 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 7559c5d5eea4..463372198099 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2859,9 +2859,7 @@ 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;
@@ -3109,14 +3107,14 @@ static void binder_transaction(struct binder_proc *proc,
 		size_t added_size;
 
 		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;
 		}
-		added_size = ALIGN(secctx_sz, sizeof(u64));
+		added_size = ALIGN(lsmctx.len, sizeof(u64));
 		extra_buffers_size += added_size;
 		if (extra_buffers_size < added_size) {
 			/* integer overflow of extra_buffers_size */
@@ -3143,24 +3141,22 @@ static void binder_transaction(struct binder_proc *proc,
 		t->buffer = NULL;
 		goto err_binder_alloc_buf_failed;
 	}
-	if (secctx) {
+	if (lsmctx.context) {
 		int err;
 		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;
 		err = binder_alloc_copy_to_buffer(&target_proc->alloc,
 						  t->buffer, buf_offset,
-						  secctx, secctx_sz);
+						  lsmctx.context, lsmctx.len);
 		if (err) {
 			t->security_ctx = 0;
 			WARN_ON(1);
 		}
-		lsmcontext_init(&scaff, secctx, secctx_sz, 0);
-		security_release_secctx(&scaff);
-		secctx = NULL;
+		security_release_secctx(&lsmctx);
 	}
 	t->buffer->debug_id = t->debug_id;
 	t->buffer->transaction = t;
@@ -3216,7 +3212,7 @@ static void binder_transaction(struct binder_proc *proc,
 	off_end_offset = off_start_offset + tr->offsets_size;
 	sg_buf_offset = ALIGN(off_end_offset, sizeof(void *));
 	sg_buf_end_offset = sg_buf_offset + extra_buffers_size -
-		ALIGN(secctx_sz, sizeof(u64));
+		ALIGN(lsmctx.len, sizeof(u64));
 	off_min = 0;
 	for (buffer_offset = off_start_offset; buffer_offset < off_end_offset;
 	     buffer_offset += sizeof(binder_size_t)) {
@@ -3492,10 +3488,8 @@ static void binder_transaction(struct binder_proc *proc,
 	binder_alloc_free_buf(&target_proc->alloc, t->buffer);
 err_binder_alloc_buf_failed:
 err_bad_extra_size:
-	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 c040c959b413..390cc0561bb3 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -526,7 +526,7 @@ 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);
@@ -1331,7 +1331,7 @@ 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 30ba801c91bd..4a6ad8caf423 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -93,18 +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);
-			/*scaffolding*/
-			lsmcontext_init(&context, secdata, seclen, 0);
+			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 3305c4af43a8..224c7b4a1bc0 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1178,9 +1178,8 @@ 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)
@@ -1418,25 +1417,22 @@ 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);
@@ -2061,26 +2057,23 @@ 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 9774d9947128..7d66bb7497ef 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -962,9 +962,7 @@ 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);
@@ -975,13 +973,12 @@ 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=");
@@ -1194,7 +1191,6 @@ 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;
 
@@ -1218,17 +1214,15 @@ 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);
 			}
 		}
@@ -1372,20 +1366,17 @@ 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 96d56a30ecca..27af7a6b8780 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 2f233f40c926..255bcb886a2f 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -329,13 +329,12 @@ 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;
 
@@ -344,13 +343,12 @@ 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;
 }
@@ -648,12 +646,16 @@ 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 8601fcb99f7a..8969754d7fe9 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 cc3ef03ee198..2d6668fd026c 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -306,6 +306,7 @@ 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;
@@ -314,10 +315,12 @@ 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 288c005b44c7..c03fe9a4f7b9 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -374,8 +374,6 @@ 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) &&
@@ -440,12 +438,9 @@ 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);
@@ -478,8 +473,6 @@ 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);
@@ -503,11 +496,9 @@ 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);
@@ -546,8 +537,6 @@ 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);
@@ -570,10 +559,9 @@ 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);
@@ -1091,8 +1079,6 @@ 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,
@@ -1149,15 +1135,13 @@ 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 ef139d8ae7cd..951ba0639d20 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -85,8 +85,6 @@ 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)
@@ -102,9 +100,8 @@ 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 6be4be40127e..e80b71c03062 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2109,18 +2109,22 @@ 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 = lsm_task_display(current);
 
+	memset(cp, 0, sizeof(*cp));
+
 	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
 		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
 			continue;
-		if (display == LSMBLOB_INVALID || display == hp->lsmid->slot)
+		if (display == LSMBLOB_INVALID || display == hp->lsmid->slot) {
+			cp->slot = hp->lsmid->slot;
 			return hp->hook.secid_to_secctx(
 					blob->secid[hp->lsmid->slot],
-					secdata, seclen);
+					&cp->context, &cp->len);
+		}
 	}
 	return 0;
 }
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 15/25] LSM: Use lsmcontext in security_secid_to_secctx
  2019-12-24 23:59   ` [PATCH v13 15/25] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
@ 2020-01-06 16:15     ` Stephen Smalley
  0 siblings, 0 replies; 50+ messages in thread
From: Stephen Smalley @ 2020-01-06 16:15 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul

On 12/24/19 6:59 PM, 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.
> 
> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> cc: netdev@vger.kernel.org
> ---

> diff --git a/kernel/audit.c b/kernel/audit.c
> index 3305c4af43a8..224c7b4a1bc0 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -1178,9 +1178,8 @@ 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)
> @@ -1418,25 +1417,22 @@ 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);

As I mentioned in my 2nd reply on the v12 version of this patch, you 
forgot to update this kmalloc() to use context.len, so you'll end up 
allocating too small a buffer and then writing out of bounds upon the 
memcpy below.  KASAN would have detected this for you if you enabled it 
in your kernel config.

>   		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);

^ permalink raw reply	[flat|nested] 50+ messages in thread

* [PATCH v13 16/25] LSM: Use lsmcontext in security_dentry_init_security
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (14 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 15/25] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2020-01-07 19:23     ` Stephen Smalley
  2019-12-24 23:59   ` [PATCH v13 17/25] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
                     ` (9 subsequent siblings)
  25 siblings, 1 reply; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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. SELinux is handled correctly, and
is the only current user.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 fs/nfs/nfs4proc.c        | 15 ++++++++-------
 include/linux/security.h |  7 +++----
 security/security.c      | 29 +++++++++++++++++++++++++----
 3 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index a30e36654c57..6cd2463f890b 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -112,6 +112,7 @@ 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)
@@ -121,21 +122,21 @@ 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);
+					    &dentry->d_name, &context);
+
+	label->label = context.context;
+	label->len = context.len;
+
 	if (err == 0)
 		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 390cc0561bb3..ea98dff5ec03 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -394,8 +394,8 @@ int security_add_mnt_opt(const char *option, const char *val,
 				int len, void **mnt_opts);
 int security_move_mount(const struct path *from_path, const struct path *to_path);
 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,
@@ -786,8 +786,7 @@ 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 e80b71c03062..29f070aa172c 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1011,12 +1011,33 @@ void security_inode_free(struct inode *inode)
 				inode_free_by_rcu);
 }
 
+/*
+ * security_dentry_init_security - initial context for a dentry
+ * @dentry: directory entry
+ * @mode: access mode
+ * @name: path name
+ * @context: resulting security context
+ *
+ * Use at most one security module to get the initial
+ * security context. Do not use the "display".
+ *
+ * Returns -EOPNOTSUPP if not supplied by any module or the module result.
+ */
 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);
+	struct security_hook_list *hp;
+
+	hlist_for_each_entry(hp, &security_hook_heads.dentry_init_security,
+			     list) {
+		cp->slot = hp->lsmid->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] 50+ messages in thread

* Re: [PATCH v13 16/25] LSM: Use lsmcontext in security_dentry_init_security
  2019-12-24 23:59   ` [PATCH v13 16/25] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
@ 2020-01-07 19:23     ` Stephen Smalley
  0 siblings, 0 replies; 50+ messages in thread
From: Stephen Smalley @ 2020-01-07 19:23 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul

On 12/24/19 6:59 PM, 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. SELinux is handled correctly, and
> is the only current user.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---
>   fs/nfs/nfs4proc.c        | 15 ++++++++-------
>   include/linux/security.h |  7 +++----
>   security/security.c      | 29 +++++++++++++++++++++++++----
>   3 files changed, 36 insertions(+), 15 deletions(-)
> 
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index a30e36654c57..6cd2463f890b 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -112,6 +112,7 @@ 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)
> @@ -121,21 +122,21 @@ 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);
> +					    &dentry->d_name, &context);
> +
> +	label->label = context.context;
> +	label->len = context.len;

No point in setting label->label/len if err != 0.

> +
>   	if (err == 0)
>   		return label;
>   
>   	return NULL;
> +
>   }

Leftover empty line.

>   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)
>   {

Not sure why you don't just leave the scaffolding here?

^ permalink raw reply	[flat|nested] 50+ messages in thread

* [PATCH v13 17/25] LSM: Use lsmcontext in security_inode_getsecctx
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (15 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 16/25] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 18/25] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
                     ` (8 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 fs/nfsd/nfs4xdr.c        | 23 +++++++++--------------
 include/linux/security.h |  5 +++--
 security/security.c      | 13 +++++++++++--
 3 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index e20011281915..98d20178e60f 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
 
@@ -2421,9 +2421,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 	int err;
 	struct nfs4_acl *acl = NULL;
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
-	struct lsmcontext scaff; /* scaffolding */
-	void *context = NULL;
-	int contextlen;
+	struct lsmcontext context = { };
 #endif
 	bool contextsupport = false;
 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
@@ -2481,7 +2479,7 @@ 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);
@@ -2911,8 +2909,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 
 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
 	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;
 	}
@@ -2924,10 +2921,8 @@ 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 ea98dff5ec03..49d2a778020e 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -533,7 +533,7 @@ 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);
 int security_locked_down(enum lockdown_reason what);
 #else /* CONFIG_SECURITY */
 
@@ -1358,7 +1358,8 @@ 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 29f070aa172c..affd53f04805 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2201,9 +2201,18 @@ 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);
+	struct security_hook_list *hp;
+
+	memset(cp, 0, sizeof(*cp));
+
+	hlist_for_each_entry(hp, &security_hook_heads.inode_getsecctx, list) {
+		cp->slot = hp->lsmid->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] 50+ messages in thread

* [PATCH v13 18/25] LSM: security_secid_to_secctx in netlink netfilter
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (16 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 17/25] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 19/25] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
                     ` (7 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc: netdev@vger.kernel.org
---
 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 2d6668fd026c..a1296453d8f2 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -301,12 +301,10 @@ 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;
@@ -314,15 +312,16 @@ 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)
@@ -398,8 +397,7 @@ 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))
@@ -466,7 +464,7 @@ 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);
 	}
@@ -601,7 +599,7 @@ 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)
@@ -629,10 +627,8 @@ 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:
@@ -640,10 +636,8 @@ 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] 50+ messages in thread

* [PATCH v13 19/25] NET: Store LSM netlabel data in a lsmblob
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (17 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 18/25] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2020-01-07 19:25     ` Stephen Smalley
  2020-01-09 14:34     ` Stephen Smalley
  2019-12-24 23:59   ` [PATCH v13 20/25] LSM: Verify LSM display sanity in binder Casey Schaufler
                     ` (6 subsequent siblings)
  25 siblings, 2 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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 accommodate the change. This requires that the
modules using netlabel use the lsm_id.slot to access the
correct secid when using netlabel.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/net/netlabel.h              |  8 ++--
 net/ipv4/cipso_ipv4.c               | 23 +++++++-----
 net/netlabel/netlabel_kapi.c        |  6 +--
 net/netlabel/netlabel_unlabeled.c   | 57 +++++++++++------------------
 net/netlabel/netlabel_unlabeled.h   |  2 +-
 security/selinux/hooks.c            |  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          |  5 ++-
 security/smack/smackfs.c            | 10 +++--
 12 files changed, 59 insertions(+), 62 deletions(-)

diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 43ae50337685..73fc25b4042b 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -166,7 +166,7 @@ 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
@@ -201,7 +201,7 @@ struct netlbl_lsm_secattr {
 			struct netlbl_lsm_catmap *cat;
 			u32 lvl;
 		} mls;
-		u32 secid;
+		struct lsmblob lsmblob;
 	} attr;
 };
 
@@ -415,7 +415,7 @@ 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,
@@ -523,7 +523,7 @@ 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 376882215919..adb9dffc3952 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -106,15 +106,17 @@ int cipso_v4_rbm_strictvalid = 1;
 /* Base length of the local tag (non-standard tag).
  *  Tag definition (may change between kernel versions)
  *
- * 0          8          16         24         32
- * +----------+----------+----------+----------+
- * | 10000000 | 00000110 | 32-bit secid value  |
- * +----------+----------+----------+----------+
- * | in (host byte order)|
- * +----------+----------+
- *
+ * 0          8          16                    16 + sizeof(struct lsmblob)
+ * +----------+----------+---------------------+
+ * | 10000000 | 00000110 | LSM blob data       |
+ * +----------+----------+---------------------+
+ *
+ * All secid and flag fields are in host byte order.
+ * The lsmblob structure size varies depending on which
+ * Linux security modules are built in the kernel.
+ * The data is opaque.
  */
-#define CIPSO_V4_TAG_LOC_BLEN         6
+#define CIPSO_V4_TAG_LOC_BLEN         (2 + sizeof(struct lsmblob))
 
 /*
  * Helper Functions
@@ -1467,7 +1469,8 @@ 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;
+	memcpy(&buffer[2], &secattr->attr.lsmblob,
+	       sizeof(secattr->attr.lsmblob));
 
 	return CIPSO_V4_TAG_LOC_BLEN;
 }
@@ -1487,7 +1490,7 @@ 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];
+	memcpy(&secattr->attr.lsmblob, &tag[2], sizeof(secattr->attr.lsmblob));
 	secattr->flags |= NETLBL_SECATTR_SECID;
 
 	return 0;
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index 409a3ae47ce2..f2ebd43a7992 100644
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -196,7 +196,7 @@ 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:
@@ -210,7 +210,7 @@ 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;
@@ -230,7 +230,7 @@ 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 c03fe9a4f7b9..3b0f07b59436 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -66,7 +66,7 @@ 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;
@@ -74,7 +74,7 @@ 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;
@@ -219,7 +219,7 @@ 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
@@ -230,7 +230,7 @@ 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;
@@ -242,7 +242,7 @@ 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);
@@ -259,7 +259,7 @@ 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
@@ -270,7 +270,7 @@ 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;
@@ -286,7 +286,7 @@ 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);
@@ -365,7 +365,7 @@ 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;
@@ -374,7 +374,6 @@ 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))
@@ -407,7 +406,7 @@ 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,
@@ -420,7 +419,7 @@ 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,
@@ -437,8 +436,7 @@ 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);
@@ -473,7 +471,6 @@ 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,
@@ -493,10 +490,8 @@ 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);
@@ -537,7 +532,6 @@ 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);
@@ -556,10 +550,8 @@ 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);
@@ -913,9 +905,8 @@ 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);
 }
 
@@ -963,10 +954,8 @@ 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);
 }
 
 /**
@@ -1078,8 +1067,7 @@ 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,
@@ -1117,7 +1105,7 @@ 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,
@@ -1131,11 +1119,10 @@ 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,
@@ -1487,7 +1474,7 @@ 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)
@@ -1500,7 +1487,7 @@ 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 058e3a285d56..168920780994 100644
--- a/net/netlabel/netlabel_unlabeled.h
+++ b/net/netlabel/netlabel_unlabeled.h
@@ -211,7 +211,7 @@ 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/hooks.c b/security/selinux/hooks.c
index b8501ca3c8f3..cd4743331800 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6871,7 +6871,7 @@ static int selinux_perf_event_write(struct perf_event *event)
 }
 #endif
 
-static struct lsm_id selinux_lsmid __lsm_ro_after_init = {
+struct lsm_id selinux_lsmid __lsm_ro_after_init = {
 	.lsm  = "selinux",
 	.slot = LSMBLOB_NEEDED
 };
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index ae840634e3c7..741ba0e6dd83 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -70,6 +70,7 @@
 struct netlbl_lsm_secattr;
 
 extern int selinux_enabled;
+extern struct lsm_id selinux_lsmid;
 
 /* Policy capabilities */
 enum {
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index 6a94b31b5472..d8d7603ab14e 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -108,7 +108,7 @@ 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_lsmid.slot] == sid))
 		return secattr;
 
 	return NULL;
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index a5813c7629c1..2b7680903b6b 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -3599,7 +3599,7 @@ 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_lsmid.slot];
 	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
 		rc = -EIDRM;
 		ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
@@ -3672,7 +3672,7 @@ 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_lsmid.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 2836540f9577..6e76b6b33063 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -316,6 +316,7 @@ void smk_destroy_label_list(struct list_head *list);
  * Shared data.
  */
 extern int smack_enabled;
+extern struct lsm_id smack_lsmid;
 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 9737ead06b39..9ce67e03ac49 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3775,7 +3775,8 @@ 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_lsmid.slot]);
 	/*
 	 * Without guidance regarding the smack value
 	 * for the packet fall back on the network
@@ -4592,7 +4593,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
 	.lbs_sock = sizeof(struct socket_smack),
 };
 
-static struct lsm_id smack_lsmid __lsm_ro_after_init = {
+struct lsm_id smack_lsmid __lsm_ro_after_init = {
 	.lsm  = "smack",
 	.slot = LSMBLOB_NEEDED
 };
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index e3e05c04dbd1..d10e9c96717e 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -1122,6 +1122,7 @@ 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;
@@ -1253,10 +1254,13 @@ 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_lsmid.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] 50+ messages in thread

* Re: [PATCH v13 19/25] NET: Store LSM netlabel data in a lsmblob
  2019-12-24 23:59   ` [PATCH v13 19/25] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
@ 2020-01-07 19:25     ` Stephen Smalley
  2020-01-07 21:58       ` Casey Schaufler
  2020-01-09 14:34     ` Stephen Smalley
  1 sibling, 1 reply; 50+ messages in thread
From: Stephen Smalley @ 2020-01-07 19:25 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul

On 12/24/19 6:59 PM, 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 accommodate the change. This requires that the
> modules using netlabel use the lsm_id.slot to access the
> correct secid when using netlabel.
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Reviewed-by: John Johansen <john.johansen@canonical.com>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Why is this needed for stacking AppArmor?  AA doesn't use NetLabel, at 
least not upstream AFAICS.

> ---
>   include/net/netlabel.h              |  8 ++--
>   net/ipv4/cipso_ipv4.c               | 23 +++++++-----
>   net/netlabel/netlabel_kapi.c        |  6 +--
>   net/netlabel/netlabel_unlabeled.c   | 57 +++++++++++------------------
>   net/netlabel/netlabel_unlabeled.h   |  2 +-
>   security/selinux/hooks.c            |  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          |  5 ++-
>   security/smack/smackfs.c            | 10 +++--
>   12 files changed, 59 insertions(+), 62 deletions(-)
> 
> diff --git a/include/net/netlabel.h b/include/net/netlabel.h
> index 43ae50337685..73fc25b4042b 100644
> --- a/include/net/netlabel.h
> +++ b/include/net/netlabel.h
> @@ -166,7 +166,7 @@ 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
> @@ -201,7 +201,7 @@ struct netlbl_lsm_secattr {
>   			struct netlbl_lsm_catmap *cat;
>   			u32 lvl;
>   		} mls;
> -		u32 secid;
> +		struct lsmblob lsmblob;
>   	} attr;
>   };
>   
> @@ -415,7 +415,7 @@ 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,
> @@ -523,7 +523,7 @@ 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 376882215919..adb9dffc3952 100644
> --- a/net/ipv4/cipso_ipv4.c
> +++ b/net/ipv4/cipso_ipv4.c
> @@ -106,15 +106,17 @@ int cipso_v4_rbm_strictvalid = 1;
>   /* Base length of the local tag (non-standard tag).
>    *  Tag definition (may change between kernel versions)
>    *
> - * 0          8          16         24         32
> - * +----------+----------+----------+----------+
> - * | 10000000 | 00000110 | 32-bit secid value  |
> - * +----------+----------+----------+----------+
> - * | in (host byte order)|
> - * +----------+----------+
> - *
> + * 0          8          16                    16 + sizeof(struct lsmblob)
> + * +----------+----------+---------------------+
> + * | 10000000 | 00000110 | LSM blob data       |
> + * +----------+----------+---------------------+
> + *
> + * All secid and flag fields are in host byte order.
> + * The lsmblob structure size varies depending on which
> + * Linux security modules are built in the kernel.
> + * The data is opaque.
>    */
> -#define CIPSO_V4_TAG_LOC_BLEN         6
> +#define CIPSO_V4_TAG_LOC_BLEN         (2 + sizeof(struct lsmblob))
>   
>   /*
>    * Helper Functions
> @@ -1467,7 +1469,8 @@ 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;
> +	memcpy(&buffer[2], &secattr->attr.lsmblob,
> +	       sizeof(secattr->attr.lsmblob));
>   
>   	return CIPSO_V4_TAG_LOC_BLEN;
>   }
> @@ -1487,7 +1490,7 @@ 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];
> +	memcpy(&secattr->attr.lsmblob, &tag[2], sizeof(secattr->attr.lsmblob));
>   	secattr->flags |= NETLBL_SECATTR_SECID;
>   
>   	return 0;
> diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
> index 409a3ae47ce2..f2ebd43a7992 100644
> --- a/net/netlabel/netlabel_kapi.c
> +++ b/net/netlabel/netlabel_kapi.c
> @@ -196,7 +196,7 @@ 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:
> @@ -210,7 +210,7 @@ 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;
> @@ -230,7 +230,7 @@ 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 c03fe9a4f7b9..3b0f07b59436 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -66,7 +66,7 @@ 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;
> @@ -74,7 +74,7 @@ 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;
> @@ -219,7 +219,7 @@ 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
> @@ -230,7 +230,7 @@ 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;
> @@ -242,7 +242,7 @@ 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);
> @@ -259,7 +259,7 @@ 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
> @@ -270,7 +270,7 @@ 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;
> @@ -286,7 +286,7 @@ 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);
> @@ -365,7 +365,7 @@ 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;
> @@ -374,7 +374,6 @@ 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))
> @@ -407,7 +406,7 @@ 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,
> @@ -420,7 +419,7 @@ 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,
> @@ -437,8 +436,7 @@ 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);
> @@ -473,7 +471,6 @@ 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,
> @@ -493,10 +490,8 @@ 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);
> @@ -537,7 +532,6 @@ 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);
> @@ -556,10 +550,8 @@ 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);
> @@ -913,9 +905,8 @@ 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);
>   }
>   
> @@ -963,10 +954,8 @@ 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);
>   }
>   
>   /**
> @@ -1078,8 +1067,7 @@ 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,
> @@ -1117,7 +1105,7 @@ 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,
> @@ -1131,11 +1119,10 @@ 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,
> @@ -1487,7 +1474,7 @@ 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)
> @@ -1500,7 +1487,7 @@ 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 058e3a285d56..168920780994 100644
> --- a/net/netlabel/netlabel_unlabeled.h
> +++ b/net/netlabel/netlabel_unlabeled.h
> @@ -211,7 +211,7 @@ 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/hooks.c b/security/selinux/hooks.c
> index b8501ca3c8f3..cd4743331800 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -6871,7 +6871,7 @@ static int selinux_perf_event_write(struct perf_event *event)
>   }
>   #endif
>   
> -static struct lsm_id selinux_lsmid __lsm_ro_after_init = {
> +struct lsm_id selinux_lsmid __lsm_ro_after_init = {
>   	.lsm  = "selinux",
>   	.slot = LSMBLOB_NEEDED
>   };
> diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
> index ae840634e3c7..741ba0e6dd83 100644
> --- a/security/selinux/include/security.h
> +++ b/security/selinux/include/security.h
> @@ -70,6 +70,7 @@
>   struct netlbl_lsm_secattr;
>   
>   extern int selinux_enabled;
> +extern struct lsm_id selinux_lsmid;
>   
>   /* Policy capabilities */
>   enum {
> diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
> index 6a94b31b5472..d8d7603ab14e 100644
> --- a/security/selinux/netlabel.c
> +++ b/security/selinux/netlabel.c
> @@ -108,7 +108,7 @@ 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_lsmid.slot] == sid))
>   		return secattr;
>   
>   	return NULL;
> diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
> index a5813c7629c1..2b7680903b6b 100644
> --- a/security/selinux/ss/services.c
> +++ b/security/selinux/ss/services.c
> @@ -3599,7 +3599,7 @@ 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_lsmid.slot];
>   	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
>   		rc = -EIDRM;
>   		ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
> @@ -3672,7 +3672,7 @@ 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_lsmid.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 2836540f9577..6e76b6b33063 100644
> --- a/security/smack/smack.h
> +++ b/security/smack/smack.h
> @@ -316,6 +316,7 @@ void smk_destroy_label_list(struct list_head *list);
>    * Shared data.
>    */
>   extern int smack_enabled;
> +extern struct lsm_id smack_lsmid;
>   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 9737ead06b39..9ce67e03ac49 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -3775,7 +3775,8 @@ 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_lsmid.slot]);
>   	/*
>   	 * Without guidance regarding the smack value
>   	 * for the packet fall back on the network
> @@ -4592,7 +4593,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
>   	.lbs_sock = sizeof(struct socket_smack),
>   };
>   
> -static struct lsm_id smack_lsmid __lsm_ro_after_init = {
> +struct lsm_id smack_lsmid __lsm_ro_after_init = {
>   	.lsm  = "smack",
>   	.slot = LSMBLOB_NEEDED
>   };
> diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
> index e3e05c04dbd1..d10e9c96717e 100644
> --- a/security/smack/smackfs.c
> +++ b/security/smack/smackfs.c
> @@ -1122,6 +1122,7 @@ 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;
> @@ -1253,10 +1254,13 @@ 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_lsmid.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] 50+ messages in thread

* Re: [PATCH v13 19/25] NET: Store LSM netlabel data in a lsmblob
  2020-01-07 19:25     ` Stephen Smalley
@ 2020-01-07 21:58       ` Casey Schaufler
  0 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2020-01-07 21:58 UTC (permalink / raw)
  To: Stephen Smalley, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul, Casey Schaufler

On 1/7/2020 11:25 AM, Stephen Smalley wrote:
> On 12/24/19 6:59 PM, 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 accommodate the change. This requires that the
>> modules using netlabel use the lsm_id.slot to access the
>> correct secid when using netlabel.
>>
>> Reviewed-by: Kees Cook <keescook@chromium.org>
>> Reviewed-by: John Johansen <john.johansen@canonical.com>
>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>
> Why is this needed for stacking AppArmor?  AA doesn't use NetLabel, at least not upstream AFAICS.

Netlabel uses LSM interfaces that provide/require blobs,
security_secid_to_secctx() and security_secctx_to_secid()
in particular. Either the data maintained needs to be converted
to blobs or it needs extensive scaffolding. The scaffolding would
require a mechanism to identify the lsmblob slot to be used in
netlabel. You can't always use slot 0 because it would be possible
to put AppArmor on the module list ahead of SELinux or Smack. That
would be the only case where the slot number is needed outside the
security sub-system. Since converting the netlabel data to blobs
will be necessary eventually anyway, I want to avoid having to
provide a mechanism whereby netlabel can identify which slot to
use. This is especially true since Paul has nixed the idea of
assigning netlabel to a particular security module.

^ permalink raw reply	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 19/25] NET: Store LSM netlabel data in a lsmblob
  2019-12-24 23:59   ` [PATCH v13 19/25] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
  2020-01-07 19:25     ` Stephen Smalley
@ 2020-01-09 14:34     ` Stephen Smalley
  1 sibling, 0 replies; 50+ messages in thread
From: Stephen Smalley @ 2020-01-09 14:34 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul

On 12/24/19 6:59 PM, 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 accommodate the change. This requires that the
> modules using netlabel use the lsm_id.slot to access the
> correct secid when using netlabel.
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Reviewed-by: John Johansen <john.johansen@canonical.com>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>

> ---
>   include/net/netlabel.h              |  8 ++--
>   net/ipv4/cipso_ipv4.c               | 23 +++++++-----
>   net/netlabel/netlabel_kapi.c        |  6 +--
>   net/netlabel/netlabel_unlabeled.c   | 57 +++++++++++------------------
>   net/netlabel/netlabel_unlabeled.h   |  2 +-
>   security/selinux/hooks.c            |  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          |  5 ++-
>   security/smack/smackfs.c            | 10 +++--
>   12 files changed, 59 insertions(+), 62 deletions(-)
> 
> diff --git a/include/net/netlabel.h b/include/net/netlabel.h
> index 43ae50337685..73fc25b4042b 100644
> --- a/include/net/netlabel.h
> +++ b/include/net/netlabel.h
> @@ -166,7 +166,7 @@ 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
> @@ -201,7 +201,7 @@ struct netlbl_lsm_secattr {
>   			struct netlbl_lsm_catmap *cat;
>   			u32 lvl;
>   		} mls;
> -		u32 secid;
> +		struct lsmblob lsmblob;
>   	} attr;
>   };
>   
> @@ -415,7 +415,7 @@ 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,
> @@ -523,7 +523,7 @@ 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 376882215919..adb9dffc3952 100644
> --- a/net/ipv4/cipso_ipv4.c
> +++ b/net/ipv4/cipso_ipv4.c
> @@ -106,15 +106,17 @@ int cipso_v4_rbm_strictvalid = 1;
>   /* Base length of the local tag (non-standard tag).
>    *  Tag definition (may change between kernel versions)
>    *
> - * 0          8          16         24         32
> - * +----------+----------+----------+----------+
> - * | 10000000 | 00000110 | 32-bit secid value  |
> - * +----------+----------+----------+----------+
> - * | in (host byte order)|
> - * +----------+----------+
> - *
> + * 0          8          16                    16 + sizeof(struct lsmblob)
> + * +----------+----------+---------------------+
> + * | 10000000 | 00000110 | LSM blob data       |
> + * +----------+----------+---------------------+
> + *
> + * All secid and flag fields are in host byte order.
> + * The lsmblob structure size varies depending on which
> + * Linux security modules are built in the kernel.
> + * The data is opaque.
>    */
> -#define CIPSO_V4_TAG_LOC_BLEN         6
> +#define CIPSO_V4_TAG_LOC_BLEN         (2 + sizeof(struct lsmblob))
>   
>   /*
>    * Helper Functions
> @@ -1467,7 +1469,8 @@ 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;
> +	memcpy(&buffer[2], &secattr->attr.lsmblob,
> +	       sizeof(secattr->attr.lsmblob));
>   
>   	return CIPSO_V4_TAG_LOC_BLEN;
>   }
> @@ -1487,7 +1490,7 @@ 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];
> +	memcpy(&secattr->attr.lsmblob, &tag[2], sizeof(secattr->attr.lsmblob));
>   	secattr->flags |= NETLBL_SECATTR_SECID;
>   
>   	return 0;
> diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
> index 409a3ae47ce2..f2ebd43a7992 100644
> --- a/net/netlabel/netlabel_kapi.c
> +++ b/net/netlabel/netlabel_kapi.c
> @@ -196,7 +196,7 @@ 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:
> @@ -210,7 +210,7 @@ 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;
> @@ -230,7 +230,7 @@ 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 c03fe9a4f7b9..3b0f07b59436 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -66,7 +66,7 @@ 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;
> @@ -74,7 +74,7 @@ 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;
> @@ -219,7 +219,7 @@ 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
> @@ -230,7 +230,7 @@ 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;
> @@ -242,7 +242,7 @@ 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);
> @@ -259,7 +259,7 @@ 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
> @@ -270,7 +270,7 @@ 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;
> @@ -286,7 +286,7 @@ 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);
> @@ -365,7 +365,7 @@ 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;
> @@ -374,7 +374,6 @@ 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))
> @@ -407,7 +406,7 @@ 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,
> @@ -420,7 +419,7 @@ 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,
> @@ -437,8 +436,7 @@ 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);
> @@ -473,7 +471,6 @@ 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,
> @@ -493,10 +490,8 @@ 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);
> @@ -537,7 +532,6 @@ 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);
> @@ -556,10 +550,8 @@ 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);
> @@ -913,9 +905,8 @@ 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);
>   }
>   
> @@ -963,10 +954,8 @@ 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);
>   }
>   
>   /**
> @@ -1078,8 +1067,7 @@ 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,
> @@ -1117,7 +1105,7 @@ 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,
> @@ -1131,11 +1119,10 @@ 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,
> @@ -1487,7 +1474,7 @@ 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)
> @@ -1500,7 +1487,7 @@ 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 058e3a285d56..168920780994 100644
> --- a/net/netlabel/netlabel_unlabeled.h
> +++ b/net/netlabel/netlabel_unlabeled.h
> @@ -211,7 +211,7 @@ 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/hooks.c b/security/selinux/hooks.c
> index b8501ca3c8f3..cd4743331800 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -6871,7 +6871,7 @@ static int selinux_perf_event_write(struct perf_event *event)
>   }
>   #endif
>   
> -static struct lsm_id selinux_lsmid __lsm_ro_after_init = {
> +struct lsm_id selinux_lsmid __lsm_ro_after_init = {
>   	.lsm  = "selinux",
>   	.slot = LSMBLOB_NEEDED
>   };
> diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
> index ae840634e3c7..741ba0e6dd83 100644
> --- a/security/selinux/include/security.h
> +++ b/security/selinux/include/security.h
> @@ -70,6 +70,7 @@
>   struct netlbl_lsm_secattr;
>   
>   extern int selinux_enabled;
> +extern struct lsm_id selinux_lsmid;
>   
>   /* Policy capabilities */
>   enum {
> diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
> index 6a94b31b5472..d8d7603ab14e 100644
> --- a/security/selinux/netlabel.c
> +++ b/security/selinux/netlabel.c
> @@ -108,7 +108,7 @@ 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_lsmid.slot] == sid))
>   		return secattr;
>   
>   	return NULL;
> diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
> index a5813c7629c1..2b7680903b6b 100644
> --- a/security/selinux/ss/services.c
> +++ b/security/selinux/ss/services.c
> @@ -3599,7 +3599,7 @@ 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_lsmid.slot];
>   	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
>   		rc = -EIDRM;
>   		ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
> @@ -3672,7 +3672,7 @@ 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_lsmid.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 2836540f9577..6e76b6b33063 100644
> --- a/security/smack/smack.h
> +++ b/security/smack/smack.h
> @@ -316,6 +316,7 @@ void smk_destroy_label_list(struct list_head *list);
>    * Shared data.
>    */
>   extern int smack_enabled;
> +extern struct lsm_id smack_lsmid;
>   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 9737ead06b39..9ce67e03ac49 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -3775,7 +3775,8 @@ 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_lsmid.slot]);
>   	/*
>   	 * Without guidance regarding the smack value
>   	 * for the packet fall back on the network
> @@ -4592,7 +4593,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
>   	.lbs_sock = sizeof(struct socket_smack),
>   };
>   
> -static struct lsm_id smack_lsmid __lsm_ro_after_init = {
> +struct lsm_id smack_lsmid __lsm_ro_after_init = {
>   	.lsm  = "smack",
>   	.slot = LSMBLOB_NEEDED
>   };
> diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
> index e3e05c04dbd1..d10e9c96717e 100644
> --- a/security/smack/smackfs.c
> +++ b/security/smack/smackfs.c
> @@ -1122,6 +1122,7 @@ 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;
> @@ -1253,10 +1254,13 @@ 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_lsmid.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] 50+ messages in thread

* [PATCH v13 20/25] LSM: Verify LSM display sanity in binder
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (18 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 19/25] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 21/25] Audit: Add subj_LSM fields when necessary Casey Schaufler
                     ` (5 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Verify that the tasks on the ends of a binder transaction
use the same "display" security module. This prevents confusion
of security "contexts".

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 security/security.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/security/security.c b/security/security.c
index affd53f04805..1dc3d2f71a63 100644
--- a/security/security.c
+++ b/security/security.c
@@ -738,9 +738,38 @@ int security_binder_set_context_mgr(struct task_struct *mgr)
 	return call_int_hook(binder_set_context_mgr, 0, mgr);
 }
 
+/**
+ * security_binder_transaction - Binder driver transaction check
+ * @from: source of the transaction
+ * @to: destination of the transaction
+ *
+ * Verify that the tasks have the same LSM "display", then
+ * call the security module hooks.
+ *
+ * Returns -EINVAL if the displays don't match, or the
+ * result of the security module checks.
+ */
 int security_binder_transaction(struct task_struct *from,
 				struct task_struct *to)
 {
+	int from_display = lsm_task_display(from);
+	int to_display = lsm_task_display(to);
+
+	/*
+	 * If the display is LSMBLOB_INVALID the first module that has
+	 * an entry is used. This will be in the 0 slot.
+	 *
+	 * This is currently only required if the server has requested
+	 * peer contexts, but it would be unwieldly to have too much of
+	 * the binder driver detail here.
+	 */
+	if (from_display == LSMBLOB_INVALID)
+		from_display = 0;
+	if (to_display == LSMBLOB_INVALID)
+		to_display = 0;
+	if (from_display != to_display)
+		return -EINVAL;
+
 	return call_int_hook(binder_transaction, 0, from, to);
 }
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* [PATCH v13 21/25] Audit: Add subj_LSM fields when necessary
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (19 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 20/25] LSM: Verify LSM display sanity in binder Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 22/25] Audit: Include object data for all security modules Casey Schaufler
                     ` (4 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Add record entries to identify subject data for all of the
security modules when there is more than one.

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc: netdev@vger.kernel.org
cc: linux-audit@redhat.com
---
 drivers/android/binder.c                |  2 +-
 include/linux/audit.h                   |  1 +
 include/linux/security.h                |  9 ++++-
 include/net/scm.h                       |  3 +-
 kernel/audit.c                          | 40 ++++++++++++++++++-
 kernel/audit_fsnotify.c                 |  1 +
 kernel/auditfilter.c                    |  1 +
 kernel/auditsc.c                        | 10 +++--
 net/ipv4/ip_sockglue.c                  |  2 +-
 net/netfilter/nf_conntrack_netlink.c    |  4 +-
 net/netfilter/nf_conntrack_standalone.c |  2 +-
 net/netfilter/nfnetlink_queue.c         |  2 +-
 net/netlabel/netlabel_unlabeled.c       | 11 ++++--
 net/netlabel/netlabel_user.c            |  2 +-
 net/xfrm/xfrm_policy.c                  |  2 +
 net/xfrm/xfrm_state.c                   |  2 +
 security/integrity/ima/ima_api.c        |  1 +
 security/integrity/integrity_audit.c    |  1 +
 security/security.c                     | 51 +++++++++++++++++++++++--
 19 files changed, 124 insertions(+), 23 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 463372198099..57e14b80588f 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3107,7 +3107,7 @@ static void binder_transaction(struct binder_proc *proc,
 		size_t added_size;
 
 		security_task_getsecid(proc->tsk, &blob);
-		ret = security_secid_to_secctx(&blob, &lsmctx);
+		ret = security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_DISPLAY);
 		if (ret) {
 			return_error = BR_FAILED_REPLY;
 			return_error_param = ret;
diff --git a/include/linux/audit.h b/include/linux/audit.h
index f9ceae57ca8d..2ce0e8da3922 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -161,6 +161,7 @@ extern void		    audit_log_path_denied(int type,
 extern void		    audit_log_lost(const char *message);
 
 extern int audit_log_task_context(struct audit_buffer *ab);
+extern void audit_log_task_lsms(struct audit_buffer *ab);
 extern void audit_log_task_info(struct audit_buffer *ab);
 
 extern int		    audit_update_lsm_rules(void);
diff --git a/include/linux/security.h b/include/linux/security.h
index 49d2a778020e..d7af2bbbc878 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -176,6 +176,8 @@ struct lsmblob {
 #define LSMBLOB_INVALID		-1	/* Not a valid LSM slot number */
 #define LSMBLOB_NEEDED		-2	/* Slot requested on initialization */
 #define LSMBLOB_NOT_NEEDED	-3	/* Slot not requested */
+#define LSMBLOB_DISPLAY		-4	/* Use the "display" slot */
+#define LSMBLOB_FIRST		-5	/* Use the default "display" slot */
 
 /**
  * lsmblob_init - initialize an lsmblob structure.
@@ -217,6 +219,8 @@ static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)
 	return !memcmp(bloba, blobb, sizeof(*bloba));
 }
 
+const char *security_lsm_slot_name(int slot);
+
 /* These functions are in security/commoncap.c */
 extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
 		       int cap, unsigned int opts);
@@ -526,7 +530,8 @@ 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, struct lsmcontext *cp);
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp,
+			     int display);
 int security_secctx_to_secid(const char *secdata, u32 seclen,
 			     struct lsmblob *blob);
 void security_release_secctx(struct lsmcontext *cp);
@@ -1330,7 +1335,7 @@ static inline int security_ismaclabel(const char *name)
 }
 
 static inline int security_secid_to_secctx(struct lsmblob *blob,
-					   struct lsmcontext *cp)
+					   struct lsmcontext *cp, int display)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/include/net/scm.h b/include/net/scm.h
index 4a6ad8caf423..8b5a4737e1b8 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -96,7 +96,8 @@ 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->lsmblob, &context);
+		err = security_secid_to_secctx(&scm->lsmblob, &context,
+					       LSMBLOB_DISPLAY);
 
 		if (!err) {
 			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY,
diff --git a/kernel/audit.c b/kernel/audit.c
index 224c7b4a1bc0..d40f64a47c4b 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -392,6 +392,7 @@ static int audit_log_config_change(char *function_name, u32 new, u32 old,
 	if (rc)
 		allow_changes = 0; /* Something weird, deny request */
 	audit_log_format(ab, " res=%d", allow_changes);
+	audit_log_task_lsms(ab);
 	audit_log_end(ab);
 	return rc;
 }
@@ -1097,6 +1098,7 @@ static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature
 	audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
 			 audit_feature_names[which], !!old_feature, !!new_feature,
 			 !!old_lock, !!new_lock, res);
+	audit_log_task_lsms(ab);
 	audit_log_end(ab);
 }
 
@@ -1347,6 +1349,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 					size--;
 				audit_log_n_untrustedstring(ab, data, size);
 			}
+			audit_log_task_lsms(ab);
 			audit_log_end(ab);
 		}
 		break;
@@ -1361,6 +1364,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 					 msg_type == AUDIT_ADD_RULE ?
 						"add_rule" : "remove_rule",
 					 audit_enabled);
+			audit_log_task_lsms(ab);
 			audit_log_end(ab);
 			return -EPERM;
 		}
@@ -1374,6 +1378,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		audit_log_common_recv_msg(audit_context(), &ab,
 					  AUDIT_CONFIG_CHANGE);
 		audit_log_format(ab, " op=trim res=1");
+		audit_log_task_lsms(ab);
 		audit_log_end(ab);
 		break;
 	case AUDIT_MAKE_EQUIV: {
@@ -1409,6 +1414,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		audit_log_format(ab, " new=");
 		audit_log_untrustedstring(ab, new);
 		audit_log_format(ab, " res=%d", !err);
+		audit_log_task_lsms(ab);
 		audit_log_end(ab);
 		kfree(old);
 		kfree(new);
@@ -1418,7 +1424,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		len = 0;
 		if (lsmblob_is_set(&audit_sig_lsm)) {
 			err = security_secid_to_secctx(&audit_sig_lsm,
-						       &context);
+						       &context, LSMBLOB_FIRST);
 			if (err)
 				return err;
 		}
@@ -1477,6 +1483,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 				 " old-log_passwd=%d new-log_passwd=%d res=%d",
 				 old.enabled, s.enabled, old.log_passwd,
 				 s.log_passwd, !err);
+		audit_log_task_lsms(ab);
 		audit_log_end(ab);
 		break;
 	}
@@ -2055,6 +2062,33 @@ void audit_log_key(struct audit_buffer *ab, char *key)
 		audit_log_format(ab, "(null)");
 }
 
+void audit_log_task_lsms(struct audit_buffer *ab)
+{
+	int i;
+	const char *lsm;
+	struct lsmblob blob;
+	struct lsmcontext context;
+
+	/*
+	 * Don't do anything unless there is more than one LSM
+	 * with a security context to report.
+	 */
+	if (security_lsm_slot_name(1) == NULL)
+		return;
+
+	security_task_getsecid(current, &blob);
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++) {
+		lsm = security_lsm_slot_name(i);
+		if (lsm == NULL)
+			break;
+		if (security_secid_to_secctx(&blob, &context, i))
+			continue;
+		audit_log_format(ab, " subj_%s=%s", lsm, context.context);
+		security_release_secctx(&context);
+	}
+}
+
 int audit_log_task_context(struct audit_buffer *ab)
 {
 	int error;
@@ -2065,7 +2099,7 @@ int audit_log_task_context(struct audit_buffer *ab)
 	if (!lsmblob_is_set(&blob))
 		return 0;
 
-	error = security_secid_to_secctx(&blob, &context);
+	error = security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST);
 	if (error) {
 		if (error != -EINVAL)
 			goto error_path;
@@ -2173,6 +2207,7 @@ void audit_log_path_denied(int type, const char *operation)
 	audit_log_format(ab, "op=%s", operation);
 	audit_log_task_info(ab);
 	audit_log_format(ab, " res=0");
+	audit_log_task_lsms(ab);
 	audit_log_end(ab);
 }
 
@@ -2223,6 +2258,7 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
 			 oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
 			 oldsessionid, sessionid, !rc);
 	audit_put_tty(tty);
+	audit_log_task_lsms(ab);
 	audit_log_end(ab);
 }
 
diff --git a/kernel/audit_fsnotify.c b/kernel/audit_fsnotify.c
index f0d243318452..7f8c4b1a2884 100644
--- a/kernel/audit_fsnotify.c
+++ b/kernel/audit_fsnotify.c
@@ -126,6 +126,7 @@ static void audit_mark_log_rule_change(struct audit_fsnotify_mark *audit_mark, c
 	audit_log_untrustedstring(ab, audit_mark->path);
 	audit_log_key(ab, rule->filterkey);
 	audit_log_format(ab, " list=%d res=1", rule->listnr);
+	audit_log_task_lsms(ab);
 	audit_log_end(ab);
 }
 
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 19cfbe716f9d..bf28bb599b6d 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1103,6 +1103,7 @@ static void audit_log_rule_change(char *action, struct audit_krule *rule, int re
 	audit_log_format(ab, " op=%s", action);
 	audit_log_key(ab, rule->filterkey);
 	audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
+	audit_log_task_lsms(ab);
 	audit_log_end(ab);
 }
 
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 7d66bb7497ef..7c381b1e9993 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -973,7 +973,7 @@ 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, &lsmctx)) {
+		if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) {
 			audit_log_format(ab, " obj=(none)");
 			rc = 1;
 		} else {
@@ -1218,7 +1218,8 @@ static void show_special(struct audit_context *context, int *call_panic)
 			struct lsmblob blob;
 
 			lsmblob_init(&blob, osid);
-			if (security_secid_to_secctx(&blob, &lsmcxt)) {
+			if (security_secid_to_secctx(&blob, &lsmcxt,
+						     LSMBLOB_FIRST)) {
 				audit_log_format(ab, " osid=%u", osid);
 				*call_panic = 1;
 			} else {
@@ -1370,7 +1371,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 		struct lsmcontext lsmctx;
 
 		lsmblob_init(&blob, n->osid);
-		if (security_secid_to_secctx(&blob, &lsmctx)) {
+		if (security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_FIRST)) {
 			audit_log_format(ab, " osid=%u", n->osid);
 			if (call_panic)
 				*call_panic = 2;
@@ -1479,6 +1480,7 @@ static void audit_log_exit(void)
 
 	audit_log_task_info(ab);
 	audit_log_key(ab, context->filterkey);
+	audit_log_task_lsms(ab);
 	audit_log_end(ab);
 
 	for (aux = context->aux; aux; aux = aux->next) {
@@ -2602,6 +2604,7 @@ void audit_core_dumps(long signr)
 		return;
 	audit_log_task(ab);
 	audit_log_format(ab, " sig=%ld res=1", signr);
+	audit_log_task_lsms(ab);
 	audit_log_end(ab);
 }
 
@@ -2628,6 +2631,7 @@ void audit_seccomp(unsigned long syscall, long signr, int code)
 	audit_log_format(ab, " sig=%ld arch=%x syscall=%ld compat=%d ip=0x%lx code=0x%x",
 			 signr, syscall_get_arch(current), syscall,
 			 in_compat_syscall(), KSTK_EIP(current), code);
+	audit_log_task_lsms(ab);
 	audit_log_end(ab);
 }
 
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 27af7a6b8780..10b418029cdd 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -138,7 +138,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 	if (err)
 		return;
 
-	err = security_secid_to_secctx(&lb, &context);
+	err = security_secid_to_secctx(&lb, &context, LSMBLOB_DISPLAY);
 	if (err)
 		return;
 
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 255bcb886a2f..b2f522b39a1a 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -334,7 +334,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 	struct lsmcontext context;
 
 	lsmblob_init(&blob, ct->secmark);
-	ret = security_secid_to_secctx(&blob, &context);
+	ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY);
 	if (ret)
 		return 0;
 
@@ -649,7 +649,7 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
 	struct lsmcontext context;
 
 	lsmblob_init(&blob, ct->secmark);
-	ret = security_secid_to_secctx(&blob, &context);
+	ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY);
 	if (ret)
 		return 0;
 
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 8969754d7fe9..0ff2b8300c28 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -177,7 +177,7 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 	struct lsmcontext context;
 
 	lsmblob_init(&blob, ct->secmark);
-	ret = security_secid_to_secctx(&blob, &context);
+	ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY);
 	if (ret)
 		return;
 
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index a1296453d8f2..b6f71be884e8 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -314,7 +314,7 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context)
 	if (skb->secmark) {
 		/* Any LSM might be looking for the secmark */
 		lsmblob_init(&blob, skb->secmark);
-		security_secid_to_secctx(&blob, context);
+		security_secid_to_secctx(&blob, context, LSMBLOB_DISPLAY);
 	}
 
 	read_unlock_bh(&skb->sk->sk_callback_lock);
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 3b0f07b59436..60a7665de0e3 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -436,7 +436,8 @@ int netlbl_unlhsh_add(struct net *net,
 unlhsh_add_return:
 	rcu_read_unlock();
 	if (audit_buf != NULL) {
-		if (security_secid_to_secctx(lsmblob, &context) == 0) {
+		if (security_secid_to_secctx(lsmblob, &context,
+					     LSMBLOB_FIRST) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s",
 					 context.context);
 			security_release_secctx(&context);
@@ -491,7 +492,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 		if (dev != NULL)
 			dev_put(dev);
 		if (entry != NULL &&
-		    security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
+		    security_secid_to_secctx(&entry->lsmblob, &context,
+					     LSMBLOB_FIRST) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s",
 					 context.context);
 			security_release_secctx(&context);
@@ -551,7 +553,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 		if (dev != NULL)
 			dev_put(dev);
 		if (entry != NULL &&
-		    security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
+		    security_secid_to_secctx(&entry->lsmblob, &context,
+					     LSMBLOB_FIRST) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s",
 					 context.context);
 			security_release_secctx(&context);
@@ -1122,7 +1125,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 		lsmb = (struct lsmblob *)&addr6->lsmblob;
 	}
 
-	ret_val = security_secid_to_secctx(lsmb, &context);
+	ret_val = security_secid_to_secctx(lsmb, &context, LSMBLOB_FIRST);
 	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 951ba0639d20..1941877fd16f 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -100,7 +100,7 @@ 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, &context) == 0) {
+	    security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST) == 0) {
 		audit_log_format(audit_buf, " subj=%s", context.context);
 		security_release_secctx(&context);
 	}
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index f2d1e573ea55..bd2b36a83e66 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -4206,6 +4206,7 @@ void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
 	audit_log_format(audit_buf, " res=%u", result);
 	xfrm_audit_common_policyinfo(xp, audit_buf);
+	audit_log_task_lsms(audit_buf);
 	audit_log_end(audit_buf);
 }
 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
@@ -4221,6 +4222,7 @@ void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
 	audit_log_format(audit_buf, " res=%u", result);
 	xfrm_audit_common_policyinfo(xp, audit_buf);
+	audit_log_task_lsms(audit_buf);
 	audit_log_end(audit_buf);
 }
 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index f3423562d933..bfb8402cb28d 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2642,6 +2642,7 @@ void xfrm_audit_state_add(struct xfrm_state *x, int result, bool task_valid)
 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
 	xfrm_audit_helper_sainfo(x, audit_buf);
 	audit_log_format(audit_buf, " res=%u", result);
+	audit_log_task_lsms(audit_buf);
 	audit_log_end(audit_buf);
 }
 EXPORT_SYMBOL_GPL(xfrm_audit_state_add);
@@ -2656,6 +2657,7 @@ void xfrm_audit_state_delete(struct xfrm_state *x, int result, bool task_valid)
 	xfrm_audit_helper_usrinfo(task_valid, audit_buf);
 	xfrm_audit_helper_sainfo(x, audit_buf);
 	audit_log_format(audit_buf, " res=%u", result);
+	audit_log_task_lsms(audit_buf);
 	audit_log_end(audit_buf);
 }
 EXPORT_SYMBOL_GPL(xfrm_audit_state_delete);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 1ab769fa7df6..252dc00700e8 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -363,6 +363,7 @@ void ima_audit_measurement(struct integrity_iint_cache *iint,
 	audit_log_format(ab, " hash=\"%s:%s\"", algo_name, hash);
 
 	audit_log_task_info(ab);
+	audit_log_task_lsms(ab);
 	audit_log_end(ab);
 
 	iint->flags |= IMA_AUDITED;
diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c
index 5109173839cc..bca89ae72e3d 100644
--- a/security/integrity/integrity_audit.c
+++ b/security/integrity/integrity_audit.c
@@ -54,5 +54,6 @@ void integrity_audit_msg(int audit_msgno, struct inode *inode,
 		audit_log_format(ab, " ino=%lu", inode->i_ino);
 	}
 	audit_log_format(ab, " res=%d", !result);
+	audit_log_task_lsms(ab);
 	audit_log_end(ab);
 }
diff --git a/security/security.c b/security/security.c
index 1dc3d2f71a63..6d05222aac9c 100644
--- a/security/security.c
+++ b/security/security.c
@@ -449,7 +449,31 @@ static int lsm_append(const char *new, char **result)
  * Pointers to the LSM id structures for local use.
  */
 static int lsm_slot __lsm_ro_after_init;
-static struct lsm_id *lsm_slotlist[LSMBLOB_ENTRIES];
+static struct lsm_id *lsm_slotlist[LSMBLOB_ENTRIES] __lsm_ro_after_init;
+
+/**
+ * security_lsm_slot_name - Get the name of the security module in a slot
+ * @slot: index into the "display" slot list.
+ *
+ * Provide the name of the security module associated with
+ * a display slot.
+ *
+ * If @slot is LSMBLOB_INVALID return the value
+ * for slot 0 if it has been set, otherwise NULL.
+ *
+ * Returns a pointer to the name string or NULL.
+ */
+const char *security_lsm_slot_name(int slot)
+{
+	if (slot == LSMBLOB_INVALID)
+		slot = 0;
+	else if (slot >= LSMBLOB_ENTRIES || slot < 0)
+		return NULL;
+
+	if (lsm_slotlist[slot] == NULL)
+		return NULL;
+	return lsm_slotlist[slot]->lsm;
+}
 
 /**
  * security_add_hooks - Add a modules hooks to the hook lists.
@@ -2159,13 +2183,32 @@ int security_ismaclabel(const char *name)
 }
 EXPORT_SYMBOL(security_ismaclabel);
 
-int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp,
+			     int display)
 {
 	struct security_hook_list *hp;
-	int display = lsm_task_display(current);
 
 	memset(cp, 0, sizeof(*cp));
 
+	/*
+	 * display either is the slot number use for formatting
+	 * or an instruction on which relative slot to use.
+	 */
+	if (display == LSMBLOB_DISPLAY)
+		display = lsm_task_display(current);
+	else if (display == LSMBLOB_FIRST)
+		display = LSMBLOB_INVALID;
+	else if (display < 0) {
+		WARN_ONCE(true,
+			"LSM: security_secid_to_secctx unknown display\n");
+		display = LSMBLOB_INVALID;
+	} else if (display >= lsm_slot) {
+		WARN_ONCE(true,
+			"LSM: security_secid_to_secctx invalid display\n");
+		display = LSMBLOB_INVALID;
+	}
+
+
 	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
 		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
 			continue;
@@ -2176,7 +2219,7 @@ int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
 					&cp->context, &cp->len);
 		}
 	}
-	return 0;
+	return -EOPNOTSUPP;
 }
 EXPORT_SYMBOL(security_secid_to_secctx);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* [PATCH v13 22/25] Audit: Include object data for all security modules
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (20 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 21/25] Audit: Add subj_LSM fields when necessary Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 23/25] NET: Add SO_PEERCONTEXT for multiple LSMs Casey Schaufler
                     ` (3 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

When there is more than one context displaying security
module extend what goes into the audit record by supplimenting
the "obj=" with an "obj_<lsm>=" for each such security
module.

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc:linux-audit@redhat.com
---
 kernel/audit.h   |   4 +-
 kernel/auditsc.c | 110 ++++++++++++++++++++++++-----------------------
 2 files changed, 58 insertions(+), 56 deletions(-)

diff --git a/kernel/audit.h b/kernel/audit.h
index f65f516913c6..9a26ba213f6a 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -78,7 +78,7 @@ struct audit_names {
 	kuid_t			uid;
 	kgid_t			gid;
 	dev_t			rdev;
-	u32			osid;
+	struct lsmblob		oblob;
 	struct audit_cap_data	fcap;
 	unsigned int		fcap_ver;
 	unsigned char		type;		/* record type */
@@ -152,7 +152,7 @@ struct audit_context {
 			kuid_t			uid;
 			kgid_t			gid;
 			umode_t			mode;
-			u32			osid;
+			struct lsmblob		oblob;
 			int			has_perm;
 			uid_t			perm_uid;
 			gid_t			perm_gid;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 7c381b1e9993..28fea2e73040 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -659,17 +659,15 @@ 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->oblob,
 								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->oblob,
 								f->type,
 								f->op,
 								f->lsm_rule)) {
@@ -681,8 +679,7 @@ 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.oblob,
 							      f->type, f->op,
 							      f->lsm_rule))
 					++result;
@@ -956,13 +953,57 @@ static inline void audit_free_context(struct audit_context *context)
 	kfree(context);
 }
 
+static int audit_log_object_context(struct audit_buffer *ab,
+				    struct lsmblob *blob)
+{
+	struct lsmcontext context;
+	const char *lsm;
+	int i;
+
+	/*
+	 * None of the installed modules have object labels.
+	 */
+	if (security_lsm_slot_name(0) == NULL)
+		return 0;
+
+	if (blob->secid[0] != 0) {
+		if (security_secid_to_secctx(blob, &context, 0)) {
+			audit_log_format(ab, " obj=?");
+			return 1;
+		}
+		audit_log_format(ab, " obj=%s", context.context);
+		security_release_secctx(&context);
+	}
+
+	/*
+	 * Don't do anything more unless there is more than one LSM
+	 * with a security context to report.
+	 */
+	if (security_lsm_slot_name(1) == NULL)
+		return 0;
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++) {
+		lsm = security_lsm_slot_name(i);
+		if (lsm == NULL)
+			break;
+		if (blob->secid[i] == 0)
+			continue;
+		if (security_secid_to_secctx(blob, &context, i)) {
+			audit_log_format(ab, " obj_%s=?", lsm);
+			continue;
+		}
+		audit_log_format(ab, " obj_%s=%s", lsm, context.context);
+		security_release_secctx(&context);
+	}
+	return 0;
+}
+
 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 				 kuid_t auid, kuid_t uid,
 				 unsigned int sessionid,
 				 struct lsmblob *blob, char *comm)
 {
 	struct audit_buffer *ab;
-	struct lsmcontext lsmctx;
 	int rc = 0;
 
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
@@ -972,15 +1013,7 @@ 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 (lsmblob_is_set(blob)) {
-		if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) {
-			audit_log_format(ab, " obj=(none)");
-			rc = 1;
-		} else {
-			audit_log_format(ab, " obj=%s", lsmctx.context);
-			security_release_secctx(&lsmctx);
-		}
-	}
+	rc = audit_log_object_context(ab, blob);
 	audit_log_format(ab, " ocomm=");
 	audit_log_untrustedstring(ab, comm);
 	audit_log_end(ab);
@@ -1207,26 +1240,14 @@ 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 *oblob = & context->ipc.oblob;
 
 		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) {
-			struct lsmcontext lsmcxt;
-			struct lsmblob blob;
-
-			lsmblob_init(&blob, osid);
-			if (security_secid_to_secctx(&blob, &lsmcxt,
-						     LSMBLOB_FIRST)) {
-				audit_log_format(ab, " osid=%u", osid);
-				*call_panic = 1;
-			} else {
-				audit_log_format(ab, " obj=%s", lsmcxt.context);
-				security_release_secctx(&lsmcxt);
-			}
-		}
+		if (audit_log_object_context(ab, oblob))
+			*call_panic = 1;
 		if (context->ipc.has_perm) {
 			audit_log_end(ab);
 			ab = audit_log_start(context, GFP_KERNEL,
@@ -1366,20 +1387,8 @@ 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;
-		struct lsmcontext lsmctx;
-
-		lsmblob_init(&blob, n->osid);
-		if (security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_FIRST)) {
-			audit_log_format(ab, " osid=%u", n->osid);
-			if (call_panic)
-				*call_panic = 2;
-		} else {
-			audit_log_format(ab, " obj=%s", lsmctx.context);
-			security_release_secctx(&lsmctx);
-		}
-	}
+	if (audit_log_object_context(ab, &n->oblob) && call_panic)
+		*call_panic = 2;
 
 	/* log the audit_names record type */
 	switch (n->type) {
@@ -1929,17 +1938,13 @@ static 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->oblob);
 	if (flags & AUDIT_INODE_NOEVAL) {
 		name->fcap_ver = -1;
 		return;
@@ -2285,14 +2290,11 @@ 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.oblob);
 	context->type = AUDIT_IPC;
 }
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* [PATCH v13 23/25] NET: Add SO_PEERCONTEXT for multiple LSMs
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (21 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 22/25] Audit: Include object data for all security modules Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2020-01-06 17:15     ` Stephen Smalley
  2019-12-24 23:59   ` [PATCH 24/25] LSM: Add /proc attr entry for full LSM context Casey Schaufler
                     ` (2 subsequent siblings)
  25 siblings, 1 reply; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

The getsockopt SO_PEERSEC provides the LSM based security
information for a single module, but for reasons of backward
compatibility cannot include the information for multiple
modules. A new option SO_PEERCONTEXT is added to report the
security "context" of multiple modules using a "compound" format

        lsm1\0value\0lsm2\0value\0

This is expected to be used by system services, including dbus-daemon.
The exact format of a compound context has been the subject of
considerable debate. This format was suggested by Simon McVittie,
a dbus maintainer with a significant stake in the format being
usable.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc: netdev@vger.kernel.org
cc: linux-api@vger.kernel.org
---
 Documentation/security/lsm.rst        |  15 ++++
 arch/alpha/include/uapi/asm/socket.h  |   1 +
 arch/mips/include/uapi/asm/socket.h   |   1 +
 arch/parisc/include/uapi/asm/socket.h |   1 +
 arch/sparc/include/uapi/asm/socket.h  |   1 +
 include/linux/lsm_hooks.h             |   9 +-
 include/linux/security.h              |  10 ++-
 include/uapi/asm-generic/socket.h     |   1 +
 net/core/sock.c                       |   7 +-
 security/apparmor/lsm.c               |  20 ++---
 security/security.c                   | 115 +++++++++++++++++++++++---
 security/selinux/hooks.c              |  20 ++---
 security/smack/smack_lsm.c            |  31 +++----
 13 files changed, 170 insertions(+), 62 deletions(-)

diff --git a/Documentation/security/lsm.rst b/Documentation/security/lsm.rst
index aadf47c808c0..77cc326a52cc 100644
--- a/Documentation/security/lsm.rst
+++ b/Documentation/security/lsm.rst
@@ -199,3 +199,18 @@ capability-related fields:
 -  ``fs/nfsd/auth.c``::c:func:`nfsd_setuser()`
 
 -  ``fs/proc/array.c``::c:func:`task_cap()`
+
+LSM External Interfaces
+=======================
+
+The LSM infrastructure does not generally provide external interfaces.
+The individual security modules provide what external interfaces they
+require. The infrastructure does provide two interfaces for the special
+case where multiple security modules provide a process context. This
+is provided in compound context format.
+
+-  `lsm1\0value\0lsm2\0value\0`
+
+The special file ``/proc/pid/attr/context`` provides the security
+context of the identified process. The socket option SO_PEERCONTEXT
+provides the security context of a packet.
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index de6c4df61082..b26fb34e4226 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -123,6 +123,7 @@
 #define SO_SNDTIMEO_NEW         67
 
 #define SO_DETACH_REUSEPORT_BPF 68
+#define SO_PEERCONTEXT          69
 
 #if !defined(__KERNEL__)
 
diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
index d0a9ed2ca2d6..10e03507b1ed 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -134,6 +134,7 @@
 #define SO_SNDTIMEO_NEW         67
 
 #define SO_DETACH_REUSEPORT_BPF 68
+#define SO_PEERCONTEXT          69
 
 #if !defined(__KERNEL__)
 
diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
index 10173c32195e..e11df59a84d1 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -115,6 +115,7 @@
 #define SO_SNDTIMEO_NEW         0x4041
 
 #define SO_DETACH_REUSEPORT_BPF 0x4042
+#define SO_PEERCONTEXT          0x4043
 
 #if !defined(__KERNEL__)
 
diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
index 8029b681fc7c..5b41ef778040 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -116,6 +116,7 @@
 #define SO_SNDTIMEO_NEW          0x0045
 
 #define SO_DETACH_REUSEPORT_BPF  0x0047
+#define SO_PEERCONTEXT           0x0048
 
 #if !defined(__KERNEL__)
 
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 2bf82e1cf347..2ae10e7f81a7 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -880,8 +880,8 @@
  *	SO_GETPEERSEC.  For tcp sockets this can be meaningful if the
  *	socket is associated with an ipsec SA.
  *	@sock is the local socket.
- *	@optval userspace memory where the security state is to be copied.
- *	@optlen userspace int where the module should copy the actual length
+ *	@optval memory where the security state is to be copied.
+ *	@optlen int where the module should copy the actual length
  *	of the security state.
  *	@len as input is the maximum length to copy to userspace provided
  *	by the caller.
@@ -1724,9 +1724,8 @@ union security_list_options {
 	int (*socket_setsockopt)(struct socket *sock, int level, int optname);
 	int (*socket_shutdown)(struct socket *sock, int how);
 	int (*socket_sock_rcv_skb)(struct sock *sk, struct sk_buff *skb);
-	int (*socket_getpeersec_stream)(struct socket *sock,
-					char __user *optval,
-					int __user *optlen, unsigned len);
+	int (*socket_getpeersec_stream)(struct socket *sock, char **optval,
+					int *optlen, unsigned len);
 	int (*socket_getpeersec_dgram)(struct socket *sock,
 					struct sk_buff *skb, u32 *secid);
 	int (*sk_alloc_security)(struct sock *sk, int family, gfp_t priority);
diff --git a/include/linux/security.h b/include/linux/security.h
index d7af2bbbc878..26967055a002 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -178,6 +178,7 @@ struct lsmblob {
 #define LSMBLOB_NOT_NEEDED	-3	/* Slot not requested */
 #define LSMBLOB_DISPLAY		-4	/* Use the "display" slot */
 #define LSMBLOB_FIRST		-5	/* Use the default "display" slot */
+#define LSMBLOB_COMPOUND	-6	/* A compound "display" */
 
 /**
  * lsmblob_init - initialize an lsmblob structure.
@@ -1396,7 +1397,8 @@ int security_socket_setsockopt(struct socket *sock, int level, int optname);
 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 __user *optlen, unsigned len,
+				      int display);
 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);
@@ -1530,8 +1532,10 @@ static inline int security_sock_rcv_skb(struct sock *sk,
 	return 0;
 }
 
-static inline int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
-						    int __user *optlen, unsigned len)
+static inline int security_socket_getpeersec_stream(struct socket *sock,
+						    char __user *optval,
+						    int __user *optlen,
+						    unsigned len, int display)
 {
 	return -ENOPROTOOPT;
 }
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index 77f7c1638eb1..e3a853d53705 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -118,6 +118,7 @@
 #define SO_SNDTIMEO_NEW         67
 
 #define SO_DETACH_REUSEPORT_BPF 68
+#define SO_PEERCONTEXT          69
 
 #if !defined(__KERNEL__)
 
diff --git a/net/core/sock.c b/net/core/sock.c
index 043db3ce023e..63b7eda81a90 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1411,7 +1411,12 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case SO_PEERSEC:
-		return security_socket_getpeersec_stream(sock, optval, optlen, len);
+		return security_socket_getpeersec_stream(sock, optval, optlen,
+							 len, LSMBLOB_DISPLAY);
+
+	case SO_PEERCONTEXT:
+		return security_socket_getpeersec_stream(sock, optval, optlen,
+							 len, LSMBLOB_COMPOUND);
 
 	case SO_MARK:
 		v.val = sk->sk_mark;
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 16b992235c11..34edfd29c32f 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1078,10 +1078,8 @@ static struct aa_label *sk_peer_label(struct sock *sk)
  *
  * Note: for tcp only valid if using ipsec or cipso on lan
  */
-static int apparmor_socket_getpeersec_stream(struct socket *sock,
-					     char __user *optval,
-					     int __user *optlen,
-					     unsigned int len)
+static int apparmor_socket_getpeersec_stream(struct socket *sock, char **optval,
+					     int *optlen, unsigned int len)
 {
 	char *name;
 	int slen, error = 0;
@@ -1101,17 +1099,11 @@ static int apparmor_socket_getpeersec_stream(struct socket *sock,
 	if (slen < 0) {
 		error = -ENOMEM;
 	} else {
-		if (slen > len) {
+		if (slen > len)
 			error = -ERANGE;
-		} else if (copy_to_user(optval, name, slen)) {
-			error = -EFAULT;
-			goto out;
-		}
-		if (put_user(slen, optlen))
-			error = -EFAULT;
-out:
-		kfree(name);
-
+		else
+			*optval = name;
+		*optlen = slen;
 	}
 
 done:
diff --git a/security/security.c b/security/security.c
index 6d05222aac9c..80539dfd0245 100644
--- a/security/security.c
+++ b/security/security.c
@@ -723,6 +723,42 @@ static void __init lsm_early_task(struct task_struct *task)
 		panic("%s: Early task alloc failed.\n", __func__);
 }
 
+/**
+ * append_ctx - append a lsm/context pair to a compound context
+ * @ctx: the existing compound context
+ * @ctxlen: size of the old context, including terminating nul byte
+ * @lsm: new lsm name, nul terminated
+ * @new: new context, possibly nul terminated
+ * @newlen: maximum size of @new
+ *
+ * replace @ctx with a new compound context, appending @newlsm and @new
+ * to @ctx. On exit the new data replaces the old, which is freed.
+ * @ctxlen is set to the new size, which includes a trailing nul byte.
+ *
+ * Returns 0 on success, -ENOMEM if no memory is available.
+ */
+static int append_ctx(char **ctx, int *ctxlen, const char *lsm, char *new,
+		      int newlen)
+{
+	char *final;
+	int llen;
+
+	llen = strlen(lsm) + 1;
+	newlen = strnlen(new, newlen) + 1;
+
+	final = kzalloc(*ctxlen + llen + newlen, GFP_KERNEL);
+	if (final == NULL)
+		return -ENOMEM;
+	if (*ctxlen)
+		memcpy(final, *ctx, *ctxlen);
+	memcpy(final + *ctxlen, lsm, llen);
+	memcpy(final + *ctxlen + llen, new, newlen);
+	kfree(*ctx);
+	*ctx = final;
+	*ctxlen = *ctxlen + llen + newlen;
+	return 0;
+}
+
 /*
  * Hook list operation macros.
  *
@@ -2164,8 +2200,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 	hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
 		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
 			continue;
-		if (lsm == NULL && *display != LSMBLOB_INVALID &&
-		    *display != hp->lsmid->slot)
+		if (lsm == NULL && display != NULL &&
+		    *display != LSMBLOB_INVALID && *display != hp->lsmid->slot)
 			continue;
 		return hp->hook.setprocattr(name, value, size);
 	}
@@ -2245,12 +2281,21 @@ void security_release_secctx(struct lsmcontext *cp)
 {
 	struct security_hook_list *hp;
 
+	if (cp->slot == LSMBLOB_INVALID)
+		return;
+
+	if (cp->slot == LSMBLOB_COMPOUND) {
+		kfree(cp->context);
+		goto clear_out;
+	}
+
 	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
 		if (cp->slot == hp->lsmid->slot) {
 			hp->hook.release_secctx(cp->context, cp->len);
 			break;
 		}
 
+clear_out:
 	memset(cp, 0, sizeof(*cp));
 }
 EXPORT_SYMBOL(security_release_secctx);
@@ -2383,17 +2428,67 @@ int security_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 EXPORT_SYMBOL(security_sock_rcv_skb);
 
 int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
-				      int __user *optlen, unsigned len)
+				      int __user *optlen, unsigned len,
+				      int display)
 {
-	int display = lsm_task_display(current);
 	struct security_hook_list *hp;
+	char *final = NULL;
+	char *cp;
+	int rc = 0;
+	unsigned finallen = 0;
+	unsigned clen = 0;
 
-	hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_stream,
-			     list)
-		if (display == LSMBLOB_INVALID || display == hp->lsmid->slot)
-			return hp->hook.socket_getpeersec_stream(sock, optval,
-								 optlen, len);
-	return -ENOPROTOOPT;
+	switch (display) {
+	case LSMBLOB_DISPLAY:
+		rc = -ENOPROTOOPT;
+		display = lsm_task_display(current);
+		hlist_for_each_entry(hp,
+				&security_hook_heads.socket_getpeersec_stream,
+				list)
+			if (display == LSMBLOB_INVALID ||
+			    display == hp->lsmid->slot) {
+				rc = hp->hook.socket_getpeersec_stream(sock,
+							&final, &finallen, len);
+				break;
+			}
+		break;
+	case LSMBLOB_COMPOUND:
+		/*
+		 * A compound context, in the form [lsm\0value\0]...
+		 */
+		hlist_for_each_entry(hp,
+				&security_hook_heads.socket_getpeersec_stream,
+				list) {
+			rc = hp->hook.socket_getpeersec_stream(sock, &cp, &clen,
+							       len);
+			if (rc == -EINVAL || rc == -ENOPROTOOPT) {
+				rc = 0;
+				continue;
+			}
+			if (rc) {
+				kfree(final);
+				return rc;
+			}
+			rc = append_ctx(&final, &finallen, hp->lsmid->lsm,
+					cp, clen);
+		}
+		if (final == NULL)
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (finallen > len)
+		rc = -ERANGE;
+	else if (copy_to_user(optval, final, finallen))
+		rc = -EFAULT;
+
+	if (put_user(finallen, optlen))
+		rc = -EFAULT;
+
+	kfree(final);
+	return rc;
 }
 
 int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index cd4743331800..c3e6fd3f8c56 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -5056,10 +5056,8 @@ 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 int len)
+static int selinux_socket_getpeersec_stream(struct socket *sock, char **optval,
+					    int *optlen, unsigned int len)
 {
 	int err = 0;
 	char *scontext;
@@ -5079,18 +5077,12 @@ static int selinux_socket_getpeersec_stream(struct socket *sock,
 	if (err)
 		return err;
 
-	if (scontext_len > len) {
+	if (scontext_len > len)
 		err = -ERANGE;
-		goto out_len;
-	}
-
-	if (copy_to_user(optval, scontext, scontext_len))
-		err = -EFAULT;
+	else
+		*optval = scontext;
 
-out_len:
-	if (put_user(scontext_len, optlen))
-		err = -EFAULT;
-	kfree(scontext);
+	*optlen = scontext_len;
 	return err;
 }
 
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 9ce67e03ac49..316c5faf9053 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3957,28 +3957,29 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
  *
  * returns zero on success, an error code otherwise
  */
-static int smack_socket_getpeersec_stream(struct socket *sock,
-					  char __user *optval,
-					  int __user *optlen, unsigned len)
+static int smack_socket_getpeersec_stream(struct socket *sock, char **optval,
+					  int *optlen, unsigned len)
 {
-	struct socket_smack *ssp;
-	char *rcp = "";
-	int slen = 1;
+	struct socket_smack *ssp = smack_sock(sock->sk);
+	char *rcp;
+	int slen;
 	int rc = 0;
 
-	ssp = smack_sock(sock->sk);
-	if (ssp->smk_packet != NULL) {
-		rcp = ssp->smk_packet->smk_known;
-		slen = strlen(rcp) + 1;
+	if (ssp->smk_packet == NULL) {
+		*optlen = 0;
+		return -EINVAL;
 	}
 
+	rcp = ssp->smk_packet->smk_known;
+	slen = strlen(rcp) + 1;
 	if (slen > len)
 		rc = -ERANGE;
-	else if (copy_to_user(optval, rcp, slen) != 0)
-		rc = -EFAULT;
-
-	if (put_user(slen, optlen) != 0)
-		rc = -EFAULT;
+	else {
+		*optval = kstrdup(rcp, GFP_KERNEL);
+		if (*optval == NULL)
+			rc = -ENOMEM;
+	}
+	*optlen = slen;
 
 	return rc;
 }
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 23/25] NET: Add SO_PEERCONTEXT for multiple LSMs
  2019-12-24 23:59   ` [PATCH v13 23/25] NET: Add SO_PEERCONTEXT for multiple LSMs Casey Schaufler
@ 2020-01-06 17:15     ` Stephen Smalley
  2020-01-06 17:29       ` Simon McVittie
  0 siblings, 1 reply; 50+ messages in thread
From: Stephen Smalley @ 2020-01-06 17:15 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul

On 12/24/19 6:59 PM, Casey Schaufler wrote:
> The getsockopt SO_PEERSEC provides the LSM based security
> information for a single module, but for reasons of backward
> compatibility cannot include the information for multiple
> modules. A new option SO_PEERCONTEXT is added to report the
> security "context" of multiple modules using a "compound" format
> 
>          lsm1\0value\0lsm2\0value\0
> 
> This is expected to be used by system services, including dbus-daemon.
> The exact format of a compound context has been the subject of
> considerable debate. This format was suggested by Simon McVittie,
> a dbus maintainer with a significant stake in the format being
> usable.

Since upstream AA does not currently ever set the peer label info, there 
is no need for this support for stacking upstream AA today, and there is 
no way to test this functionality with more than one module present 
currently in an upstream kernel.  Either fix AA to actually implement 
the functionality so it can be tested properly, or drop it from this 
series please.  I don't understand why AA continues to keep this kind of 
basic and longstanding downstream functionality out of tree.

> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> cc: netdev@vger.kernel.org
> cc: linux-api@vger.kernel.org
> ---
>   Documentation/security/lsm.rst        |  15 ++++
>   arch/alpha/include/uapi/asm/socket.h  |   1 +
>   arch/mips/include/uapi/asm/socket.h   |   1 +
>   arch/parisc/include/uapi/asm/socket.h |   1 +
>   arch/sparc/include/uapi/asm/socket.h  |   1 +
>   include/linux/lsm_hooks.h             |   9 +-
>   include/linux/security.h              |  10 ++-
>   include/uapi/asm-generic/socket.h     |   1 +
>   net/core/sock.c                       |   7 +-
>   security/apparmor/lsm.c               |  20 ++---
>   security/security.c                   | 115 +++++++++++++++++++++++---
>   security/selinux/hooks.c              |  20 ++---
>   security/smack/smack_lsm.c            |  31 +++----
>   13 files changed, 170 insertions(+), 62 deletions(-)
> 
> diff --git a/Documentation/security/lsm.rst b/Documentation/security/lsm.rst
> index aadf47c808c0..77cc326a52cc 100644
> --- a/Documentation/security/lsm.rst
> +++ b/Documentation/security/lsm.rst
> @@ -199,3 +199,18 @@ capability-related fields:
>   -  ``fs/nfsd/auth.c``::c:func:`nfsd_setuser()`
>   
>   -  ``fs/proc/array.c``::c:func:`task_cap()`
> +
> +LSM External Interfaces
> +=======================
> +
> +The LSM infrastructure does not generally provide external interfaces.
> +The individual security modules provide what external interfaces they
> +require. The infrastructure does provide two interfaces for the special
> +case where multiple security modules provide a process context. This
> +is provided in compound context format.
> +
> +-  `lsm1\0value\0lsm2\0value\0`
> +
> +The special file ``/proc/pid/attr/context`` provides the security
> +context of the identified process. The socket option SO_PEERCONTEXT
> +provides the security context of a packet.
> diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
> index de6c4df61082..b26fb34e4226 100644
> --- a/arch/alpha/include/uapi/asm/socket.h
> +++ b/arch/alpha/include/uapi/asm/socket.h
> @@ -123,6 +123,7 @@
>   #define SO_SNDTIMEO_NEW         67
>   
>   #define SO_DETACH_REUSEPORT_BPF 68
> +#define SO_PEERCONTEXT          69
>   
>   #if !defined(__KERNEL__)
>   
> diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
> index d0a9ed2ca2d6..10e03507b1ed 100644
> --- a/arch/mips/include/uapi/asm/socket.h
> +++ b/arch/mips/include/uapi/asm/socket.h
> @@ -134,6 +134,7 @@
>   #define SO_SNDTIMEO_NEW         67
>   
>   #define SO_DETACH_REUSEPORT_BPF 68
> +#define SO_PEERCONTEXT          69
>   
>   #if !defined(__KERNEL__)
>   
> diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
> index 10173c32195e..e11df59a84d1 100644
> --- a/arch/parisc/include/uapi/asm/socket.h
> +++ b/arch/parisc/include/uapi/asm/socket.h
> @@ -115,6 +115,7 @@
>   #define SO_SNDTIMEO_NEW         0x4041
>   
>   #define SO_DETACH_REUSEPORT_BPF 0x4042
> +#define SO_PEERCONTEXT          0x4043
>   
>   #if !defined(__KERNEL__)
>   
> diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
> index 8029b681fc7c..5b41ef778040 100644
> --- a/arch/sparc/include/uapi/asm/socket.h
> +++ b/arch/sparc/include/uapi/asm/socket.h
> @@ -116,6 +116,7 @@
>   #define SO_SNDTIMEO_NEW          0x0045
>   
>   #define SO_DETACH_REUSEPORT_BPF  0x0047
> +#define SO_PEERCONTEXT           0x0048
>   
>   #if !defined(__KERNEL__)
>   
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index 2bf82e1cf347..2ae10e7f81a7 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -880,8 +880,8 @@
>    *	SO_GETPEERSEC.  For tcp sockets this can be meaningful if the
>    *	socket is associated with an ipsec SA.
>    *	@sock is the local socket.
> - *	@optval userspace memory where the security state is to be copied.
> - *	@optlen userspace int where the module should copy the actual length
> + *	@optval memory where the security state is to be copied.
> + *	@optlen int where the module should copy the actual length
>    *	of the security state.
>    *	@len as input is the maximum length to copy to userspace provided
>    *	by the caller.
> @@ -1724,9 +1724,8 @@ union security_list_options {
>   	int (*socket_setsockopt)(struct socket *sock, int level, int optname);
>   	int (*socket_shutdown)(struct socket *sock, int how);
>   	int (*socket_sock_rcv_skb)(struct sock *sk, struct sk_buff *skb);
> -	int (*socket_getpeersec_stream)(struct socket *sock,
> -					char __user *optval,
> -					int __user *optlen, unsigned len);
> +	int (*socket_getpeersec_stream)(struct socket *sock, char **optval,
> +					int *optlen, unsigned len);
>   	int (*socket_getpeersec_dgram)(struct socket *sock,
>   					struct sk_buff *skb, u32 *secid);
>   	int (*sk_alloc_security)(struct sock *sk, int family, gfp_t priority);
> diff --git a/include/linux/security.h b/include/linux/security.h
> index d7af2bbbc878..26967055a002 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -178,6 +178,7 @@ struct lsmblob {
>   #define LSMBLOB_NOT_NEEDED	-3	/* Slot not requested */
>   #define LSMBLOB_DISPLAY		-4	/* Use the "display" slot */
>   #define LSMBLOB_FIRST		-5	/* Use the default "display" slot */
> +#define LSMBLOB_COMPOUND	-6	/* A compound "display" */
>   
>   /**
>    * lsmblob_init - initialize an lsmblob structure.
> @@ -1396,7 +1397,8 @@ int security_socket_setsockopt(struct socket *sock, int level, int optname);
>   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 __user *optlen, unsigned len,
> +				      int display);
>   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);
> @@ -1530,8 +1532,10 @@ static inline int security_sock_rcv_skb(struct sock *sk,
>   	return 0;
>   }
>   
> -static inline int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
> -						    int __user *optlen, unsigned len)
> +static inline int security_socket_getpeersec_stream(struct socket *sock,
> +						    char __user *optval,
> +						    int __user *optlen,
> +						    unsigned len, int display)
>   {
>   	return -ENOPROTOOPT;
>   }
> diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
> index 77f7c1638eb1..e3a853d53705 100644
> --- a/include/uapi/asm-generic/socket.h
> +++ b/include/uapi/asm-generic/socket.h
> @@ -118,6 +118,7 @@
>   #define SO_SNDTIMEO_NEW         67
>   
>   #define SO_DETACH_REUSEPORT_BPF 68
> +#define SO_PEERCONTEXT          69
>   
>   #if !defined(__KERNEL__)
>   
> diff --git a/net/core/sock.c b/net/core/sock.c
> index 043db3ce023e..63b7eda81a90 100644
> --- a/net/core/sock.c
> +++ b/net/core/sock.c
> @@ -1411,7 +1411,12 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
>   		break;
>   
>   	case SO_PEERSEC:
> -		return security_socket_getpeersec_stream(sock, optval, optlen, len);
> +		return security_socket_getpeersec_stream(sock, optval, optlen,
> +							 len, LSMBLOB_DISPLAY);
> +
> +	case SO_PEERCONTEXT:
> +		return security_socket_getpeersec_stream(sock, optval, optlen,
> +							 len, LSMBLOB_COMPOUND);
>   
>   	case SO_MARK:
>   		v.val = sk->sk_mark;
> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
> index 16b992235c11..34edfd29c32f 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -1078,10 +1078,8 @@ static struct aa_label *sk_peer_label(struct sock *sk)
>    *
>    * Note: for tcp only valid if using ipsec or cipso on lan
>    */
> -static int apparmor_socket_getpeersec_stream(struct socket *sock,
> -					     char __user *optval,
> -					     int __user *optlen,
> -					     unsigned int len)
> +static int apparmor_socket_getpeersec_stream(struct socket *sock, char **optval,
> +					     int *optlen, unsigned int len)
>   {
>   	char *name;
>   	int slen, error = 0;
> @@ -1101,17 +1099,11 @@ static int apparmor_socket_getpeersec_stream(struct socket *sock,
>   	if (slen < 0) {
>   		error = -ENOMEM;
>   	} else {
> -		if (slen > len) {
> +		if (slen > len)
>   			error = -ERANGE;
> -		} else if (copy_to_user(optval, name, slen)) {
> -			error = -EFAULT;
> -			goto out;
> -		}
> -		if (put_user(slen, optlen))
> -			error = -EFAULT;
> -out:
> -		kfree(name);
> -
> +		else
> +			*optval = name;
> +		*optlen = slen;
>   	}
>   
>   done:
> diff --git a/security/security.c b/security/security.c
> index 6d05222aac9c..80539dfd0245 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -723,6 +723,42 @@ static void __init lsm_early_task(struct task_struct *task)
>   		panic("%s: Early task alloc failed.\n", __func__);
>   }
>   
> +/**
> + * append_ctx - append a lsm/context pair to a compound context
> + * @ctx: the existing compound context
> + * @ctxlen: size of the old context, including terminating nul byte
> + * @lsm: new lsm name, nul terminated
> + * @new: new context, possibly nul terminated
> + * @newlen: maximum size of @new
> + *
> + * replace @ctx with a new compound context, appending @newlsm and @new
> + * to @ctx. On exit the new data replaces the old, which is freed.
> + * @ctxlen is set to the new size, which includes a trailing nul byte.
> + *
> + * Returns 0 on success, -ENOMEM if no memory is available.
> + */
> +static int append_ctx(char **ctx, int *ctxlen, const char *lsm, char *new,
> +		      int newlen)
> +{
> +	char *final;
> +	int llen;
> +
> +	llen = strlen(lsm) + 1;
> +	newlen = strnlen(new, newlen) + 1;
> +
> +	final = kzalloc(*ctxlen + llen + newlen, GFP_KERNEL);
> +	if (final == NULL)
> +		return -ENOMEM;
> +	if (*ctxlen)
> +		memcpy(final, *ctx, *ctxlen);
> +	memcpy(final + *ctxlen, lsm, llen);
> +	memcpy(final + *ctxlen + llen, new, newlen);
> +	kfree(*ctx);
> +	*ctx = final;
> +	*ctxlen = *ctxlen + llen + newlen;
> +	return 0;
> +}
> +
>   /*
>    * Hook list operation macros.
>    *
> @@ -2164,8 +2200,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>   	hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
>   		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
>   			continue;
> -		if (lsm == NULL && *display != LSMBLOB_INVALID &&
> -		    *display != hp->lsmid->slot)
> +		if (lsm == NULL && display != NULL &&
> +		    *display != LSMBLOB_INVALID && *display != hp->lsmid->slot)
>   			continue;
>   		return hp->hook.setprocattr(name, value, size);
>   	}
> @@ -2245,12 +2281,21 @@ void security_release_secctx(struct lsmcontext *cp)
>   {
>   	struct security_hook_list *hp;
>   
> +	if (cp->slot == LSMBLOB_INVALID)
> +		return;
> +
> +	if (cp->slot == LSMBLOB_COMPOUND) {
> +		kfree(cp->context);
> +		goto clear_out;
> +	}
> +
>   	hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
>   		if (cp->slot == hp->lsmid->slot) {
>   			hp->hook.release_secctx(cp->context, cp->len);
>   			break;
>   		}
>   
> +clear_out:
>   	memset(cp, 0, sizeof(*cp));
>   }
>   EXPORT_SYMBOL(security_release_secctx);
> @@ -2383,17 +2428,67 @@ int security_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
>   EXPORT_SYMBOL(security_sock_rcv_skb);
>   
>   int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
> -				      int __user *optlen, unsigned len)
> +				      int __user *optlen, unsigned len,
> +				      int display)
>   {
> -	int display = lsm_task_display(current);
>   	struct security_hook_list *hp;
> +	char *final = NULL;
> +	char *cp;
> +	int rc = 0;
> +	unsigned finallen = 0;
> +	unsigned clen = 0;
>   
> -	hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_stream,
> -			     list)
> -		if (display == LSMBLOB_INVALID || display == hp->lsmid->slot)
> -			return hp->hook.socket_getpeersec_stream(sock, optval,
> -								 optlen, len);
> -	return -ENOPROTOOPT;
> +	switch (display) {
> +	case LSMBLOB_DISPLAY:
> +		rc = -ENOPROTOOPT;
> +		display = lsm_task_display(current);
> +		hlist_for_each_entry(hp,
> +				&security_hook_heads.socket_getpeersec_stream,
> +				list)
> +			if (display == LSMBLOB_INVALID ||
> +			    display == hp->lsmid->slot) {
> +				rc = hp->hook.socket_getpeersec_stream(sock,
> +							&final, &finallen, len);
> +				break;
> +			}
> +		break;
> +	case LSMBLOB_COMPOUND:
> +		/*
> +		 * A compound context, in the form [lsm\0value\0]...
> +		 */
> +		hlist_for_each_entry(hp,
> +				&security_hook_heads.socket_getpeersec_stream,
> +				list) {
> +			rc = hp->hook.socket_getpeersec_stream(sock, &cp, &clen,
> +							       len);
> +			if (rc == -EINVAL || rc == -ENOPROTOOPT) {
> +				rc = 0;
> +				continue;
> +			}
> +			if (rc) {
> +				kfree(final);
> +				return rc;
> +			}
> +			rc = append_ctx(&final, &finallen, hp->lsmid->lsm,
> +					cp, clen);
> +		}
> +		if (final == NULL)
> +			return -EINVAL;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (finallen > len)
> +		rc = -ERANGE;
> +	else if (copy_to_user(optval, final, finallen))
> +		rc = -EFAULT;
> +
> +	if (put_user(finallen, optlen))
> +		rc = -EFAULT;
> +
> +	kfree(final);
> +	return rc;
>   }
>   
>   int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index cd4743331800..c3e6fd3f8c56 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -5056,10 +5056,8 @@ 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 int len)
> +static int selinux_socket_getpeersec_stream(struct socket *sock, char **optval,
> +					    int *optlen, unsigned int len)
>   {
>   	int err = 0;
>   	char *scontext;
> @@ -5079,18 +5077,12 @@ static int selinux_socket_getpeersec_stream(struct socket *sock,
>   	if (err)
>   		return err;
>   
> -	if (scontext_len > len) {
> +	if (scontext_len > len)
>   		err = -ERANGE;
> -		goto out_len;
> -	}
> -
> -	if (copy_to_user(optval, scontext, scontext_len))
> -		err = -EFAULT;
> +	else
> +		*optval = scontext;
>   
> -out_len:
> -	if (put_user(scontext_len, optlen))
> -		err = -EFAULT;
> -	kfree(scontext);
> +	*optlen = scontext_len;
>   	return err;
>   }
>   
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 9ce67e03ac49..316c5faf9053 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -3957,28 +3957,29 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
>    *
>    * returns zero on success, an error code otherwise
>    */
> -static int smack_socket_getpeersec_stream(struct socket *sock,
> -					  char __user *optval,
> -					  int __user *optlen, unsigned len)
> +static int smack_socket_getpeersec_stream(struct socket *sock, char **optval,
> +					  int *optlen, unsigned len)
>   {
> -	struct socket_smack *ssp;
> -	char *rcp = "";
> -	int slen = 1;
> +	struct socket_smack *ssp = smack_sock(sock->sk);
> +	char *rcp;
> +	int slen;
>   	int rc = 0;
>   
> -	ssp = smack_sock(sock->sk);
> -	if (ssp->smk_packet != NULL) {
> -		rcp = ssp->smk_packet->smk_known;
> -		slen = strlen(rcp) + 1;
> +	if (ssp->smk_packet == NULL) {
> +		*optlen = 0;
> +		return -EINVAL;
>   	}
>   
> +	rcp = ssp->smk_packet->smk_known;
> +	slen = strlen(rcp) + 1;
>   	if (slen > len)
>   		rc = -ERANGE;
> -	else if (copy_to_user(optval, rcp, slen) != 0)
> -		rc = -EFAULT;
> -
> -	if (put_user(slen, optlen) != 0)
> -		rc = -EFAULT;
> +	else {
> +		*optval = kstrdup(rcp, GFP_KERNEL);
> +		if (*optval == NULL)
> +			rc = -ENOMEM;
> +	}
> +	*optlen = slen;
>   
>   	return rc;
>   }
> 


^ permalink raw reply	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 23/25] NET: Add SO_PEERCONTEXT for multiple LSMs
  2020-01-06 17:15     ` Stephen Smalley
@ 2020-01-06 17:29       ` Simon McVittie
  2020-01-06 18:03         ` Casey Schaufler
  2020-01-06 18:43         ` Stephen Smalley
  0 siblings, 2 replies; 50+ messages in thread
From: Simon McVittie @ 2020-01-06 17:29 UTC (permalink / raw)
  To: Stephen Smalley
  Cc: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux, keescook, john.johansen, penguin-kernel, paul

On Mon, 06 Jan 2020 at 12:15:57 -0500, Stephen Smalley wrote:
> On 12/24/19 6:59 PM, Casey Schaufler wrote:
> > The getsockopt SO_PEERSEC provides the LSM based security
> > information for a single module, but for reasons of backward
> > compatibility cannot include the information for multiple
> > modules. A new option SO_PEERCONTEXT is added to report the
> > security "context" of multiple modules using a "compound" format
> > 
> >          lsm1\0value\0lsm2\0value\0
> > 
> > This is expected to be used by system services, including dbus-daemon.
> > The exact format of a compound context has been the subject of
> > considerable debate. This format was suggested by Simon McVittie,
> > a dbus maintainer with a significant stake in the format being
> > usable.
> 
> Since upstream AA does not currently ever set the peer label info, there is
> no need for this support for stacking upstream AA today, and there is no way
> to test this functionality with more than one module present currently in an
> upstream kernel.  Either fix AA to actually implement the functionality so
> it can be tested properly, or drop it from this series please.  I don't
> understand why AA continues to keep this kind of basic and longstanding
> downstream functionality out of tree.

Alternatively, a pair of tiny in-tree or out-of-tree stackable LSMs
that don't make any security decisions, and label every labellable
process/socket/thing with something predictable, would make it really
easy for both kernel and user-space developers to test this and the
user-space code that uses it (D-Bus and others).

For example, they could label process 1234 and all sockets created by
process 1234 with "contexttest1\0pid1234\0contexttest2\0process1234" or
something like that.

I'd love to see AppArmor in upstream kernels support SO_PEERSEC and
SO_PEERCONTEXT, but setting up a development machine to stack AppArmor
and SELinux (and still be able to boot, without one or the other LSM
forbidding something important) seems likely to be harder than setting
it up to load some toy LSMs.

    smcv

^ permalink raw reply	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 23/25] NET: Add SO_PEERCONTEXT for multiple LSMs
  2020-01-06 17:29       ` Simon McVittie
@ 2020-01-06 18:03         ` Casey Schaufler
  2020-01-06 18:45           ` Stephen Smalley
  2020-01-06 18:43         ` Stephen Smalley
  1 sibling, 1 reply; 50+ messages in thread
From: Casey Schaufler @ 2020-01-06 18:03 UTC (permalink / raw)
  To: Simon McVittie, Stephen Smalley
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	keescook, john.johansen, penguin-kernel, paul, Casey Schaufler

On 1/6/2020 9:29 AM, Simon McVittie wrote:
> On Mon, 06 Jan 2020 at 12:15:57 -0500, Stephen Smalley wrote:
>> On 12/24/19 6:59 PM, Casey Schaufler wrote:
>>> The getsockopt SO_PEERSEC provides the LSM based security
>>> information for a single module, but for reasons of backward
>>> compatibility cannot include the information for multiple
>>> modules. A new option SO_PEERCONTEXT is added to report the
>>> security "context" of multiple modules using a "compound" format
>>>
>>>          lsm1\0value\0lsm2\0value\0
>>>
>>> This is expected to be used by system services, including dbus-daemon.
>>> The exact format of a compound context has been the subject of
>>> considerable debate. This format was suggested by Simon McVittie,
>>> a dbus maintainer with a significant stake in the format being
>>> usable.
>> Since upstream AA does not currently ever set the peer label info, there is
>> no need for this support for stacking upstream AA today, and there is no way
>> to test this functionality with more than one module present currently in an
>> upstream kernel.  Either fix AA to actually implement the functionality so
>> it can be tested properly, or drop it from this series please.

I agree that SO_PEERCONTEXT can be deferred until such time as we have
AppArmor upstream support for SO_PEERSEC.

>>   I don't
>> understand why AA continues to keep this kind of basic and longstanding
>> downstream functionality out of tree.

Not everyone has the resource commitments of the world's largest
government. :(

> Alternatively, a pair of tiny in-tree or out-of-tree stackable LSMs
> that don't make any security decisions, and label every labellable
> process/socket/thing with something predictable, would make it really
> easy for both kernel and user-space developers to test this and the
> user-space code that uses it (D-Bus and others).

Sounds like a fun and educational project. Maybe one of our lurkers
could do something clever.

>
> For example, they could label process 1234 and all sockets created by
> process 1234 with "contexttest1\0pid1234\0contexttest2\0process1234" or
> something like that.
>
> I'd love to see AppArmor in upstream kernels support SO_PEERSEC and
> SO_PEERCONTEXT, but setting up a development machine to stack AppArmor
> and SELinux (and still be able to boot, without one or the other LSM
> forbidding something important) seems likely to be harder than setting
> it up to load some toy LSMs.

>
>     smcv


^ permalink raw reply	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 23/25] NET: Add SO_PEERCONTEXT for multiple LSMs
  2020-01-06 18:03         ` Casey Schaufler
@ 2020-01-06 18:45           ` Stephen Smalley
  0 siblings, 0 replies; 50+ messages in thread
From: Stephen Smalley @ 2020-01-06 18:45 UTC (permalink / raw)
  To: Casey Schaufler, Simon McVittie
  Cc: casey.schaufler, jmorris, linux-security-module, selinux,
	keescook, john.johansen, penguin-kernel, paul

On 1/6/20 1:03 PM, Casey Schaufler wrote:
> On 1/6/2020 9:29 AM, Simon McVittie wrote:
>> On Mon, 06 Jan 2020 at 12:15:57 -0500, Stephen Smalley wrote:
>>> On 12/24/19 6:59 PM, Casey Schaufler wrote:
>>>> The getsockopt SO_PEERSEC provides the LSM based security
>>>> information for a single module, but for reasons of backward
>>>> compatibility cannot include the information for multiple
>>>> modules. A new option SO_PEERCONTEXT is added to report the
>>>> security "context" of multiple modules using a "compound" format
>>>>
>>>>           lsm1\0value\0lsm2\0value\0
>>>>
>>>> This is expected to be used by system services, including dbus-daemon.
>>>> The exact format of a compound context has been the subject of
>>>> considerable debate. This format was suggested by Simon McVittie,
>>>> a dbus maintainer with a significant stake in the format being
>>>> usable.
>>> Since upstream AA does not currently ever set the peer label info, there is
>>> no need for this support for stacking upstream AA today, and there is no way
>>> to test this functionality with more than one module present currently in an
>>> upstream kernel.  Either fix AA to actually implement the functionality so
>>> it can be tested properly, or drop it from this series please.
> 
> I agree that SO_PEERCONTEXT can be deferred until such time as we have
> AppArmor upstream support for SO_PEERSEC.
> 
>>>    I don't
>>> understand why AA continues to keep this kind of basic and longstanding
>>> downstream functionality out of tree.
> 
> Not everyone has the resource commitments of the world's largest
> government. :(

How hard is it to upstream code that is a) entirely contained within the 
AA security module, and b) already shipping in Ubuntu kernels for quite 
some time? Seems to be more of a lack of an upstream-first philosophy 
than a resources issue...

> 
>> Alternatively, a pair of tiny in-tree or out-of-tree stackable LSMs
>> that don't make any security decisions, and label every labellable
>> process/socket/thing with something predictable, would make it really
>> easy for both kernel and user-space developers to test this and the
>> user-space code that uses it (D-Bus and others).
> 
> Sounds like a fun and educational project. Maybe one of our lurkers
> could do something clever.
> 
>>
>> For example, they could label process 1234 and all sockets created by
>> process 1234 with "contexttest1\0pid1234\0contexttest2\0process1234" or
>> something like that.
>>
>> I'd love to see AppArmor in upstream kernels support SO_PEERSEC and
>> SO_PEERCONTEXT, but setting up a development machine to stack AppArmor
>> and SELinux (and still be able to boot, without one or the other LSM
>> forbidding something important) seems likely to be harder than setting
>> it up to load some toy LSMs.
> 
>>
>>      smcv
> 


^ permalink raw reply	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 23/25] NET: Add SO_PEERCONTEXT for multiple LSMs
  2020-01-06 17:29       ` Simon McVittie
  2020-01-06 18:03         ` Casey Schaufler
@ 2020-01-06 18:43         ` Stephen Smalley
  1 sibling, 0 replies; 50+ messages in thread
From: Stephen Smalley @ 2020-01-06 18:43 UTC (permalink / raw)
  To: Simon McVittie
  Cc: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux, keescook, john.johansen, penguin-kernel, paul

On 1/6/20 12:29 PM, Simon McVittie wrote:
> On Mon, 06 Jan 2020 at 12:15:57 -0500, Stephen Smalley wrote:
>> On 12/24/19 6:59 PM, Casey Schaufler wrote:
>>> The getsockopt SO_PEERSEC provides the LSM based security
>>> information for a single module, but for reasons of backward
>>> compatibility cannot include the information for multiple
>>> modules. A new option SO_PEERCONTEXT is added to report the
>>> security "context" of multiple modules using a "compound" format
>>>
>>>           lsm1\0value\0lsm2\0value\0
>>>
>>> This is expected to be used by system services, including dbus-daemon.
>>> The exact format of a compound context has been the subject of
>>> considerable debate. This format was suggested by Simon McVittie,
>>> a dbus maintainer with a significant stake in the format being
>>> usable.
>>
>> Since upstream AA does not currently ever set the peer label info, there is
>> no need for this support for stacking upstream AA today, and there is no way
>> to test this functionality with more than one module present currently in an
>> upstream kernel.  Either fix AA to actually implement the functionality so
>> it can be tested properly, or drop it from this series please.  I don't
>> understand why AA continues to keep this kind of basic and longstanding
>> downstream functionality out of tree.
> 
> Alternatively, a pair of tiny in-tree or out-of-tree stackable LSMs
> that don't make any security decisions, and label every labellable
> process/socket/thing with something predictable, would make it really
> easy for both kernel and user-space developers to test this and the
> user-space code that uses it (D-Bus and others).
> 
> For example, they could label process 1234 and all sockets created by
> process 1234 with "contexttest1\0pid1234\0contexttest2\0process1234" or
> something like that.
> 
> I'd love to see AppArmor in upstream kernels support SO_PEERSEC and
> SO_PEERCONTEXT, but setting up a development machine to stack AppArmor
> and SELinux (and still be able to boot, without one or the other LSM
> forbidding something important) seems likely to be harder than setting
> it up to load some toy LSMs.

AA+SELinux with these patches boots fine for me with Fedora; it doesn't 
load any policy for AA but you still get a compound context from 
/proc/pid/attr/context.  Should be similar for booting with a distro 
that only enables AA by default; you'll get "kernel" for the SELinux 
part of the compound label in the absence of any policy loaded.



^ permalink raw reply	[flat|nested] 50+ messages in thread

* [PATCH 24/25] LSM: Add /proc attr entry for full LSM context
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (22 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH v13 23/25] NET: Add SO_PEERCONTEXT for multiple LSMs Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2020-01-06 16:22     ` Stephen Smalley
  2019-12-24 23:59   ` [PATCH v13 25/25] AppArmor: Remove the exclusive flag Casey Schaufler
  2020-01-03 18:53     ` Casey Schaufler
  25 siblings, 1 reply; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: casey, keescook, john.johansen, penguin-kernel, paul, sds

Add an entry /proc/.../attr/context which displays the full
process security "context" in compound format:'
        lsm1\0value\0lsm2\0value\0...
This entry is not writable.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
cc: linux-api@vger.kernel.org
---
 fs/proc/base.c      |  1 +
 security/security.c | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 950c200cb9ad..d13c2cf50e4b 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2653,6 +2653,7 @@ static const struct pid_entry attr_dir_stuff[] = {
 	ATTR(NULL, "keycreate",		0666),
 	ATTR(NULL, "sockcreate",	0666),
 	ATTR(NULL, "display",		0666),
+	ATTR(NULL, "context",		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 80539dfd0245..e94de64e114c 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2099,6 +2099,10 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
 				char **value)
 {
 	struct security_hook_list *hp;
+	char *final = NULL;
+	char *cp;
+	int rc = 0;
+	int finallen = 0;
 	int display = lsm_task_display(current);
 	int slot = 0;
 
@@ -2126,6 +2130,29 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
 		return -ENOMEM;
 	}
 
+	if (!strcmp(name, "context")) {
+		hlist_for_each_entry(hp, &security_hook_heads.getprocattr,
+				     list) {
+			rc = hp->hook.getprocattr(p, "current", &cp);
+			if (rc == -EINVAL || rc == -ENOPROTOOPT)
+				continue;
+			if (rc < 0) {
+				kfree(final);
+				return rc;
+			}
+			rc = append_ctx(&final, &finallen, hp->lsmid->lsm,
+					cp, rc);
+			if (rc < 0) {
+				kfree(final);
+				return rc;
+			}
+		}
+		if (final == NULL)
+			return -EINVAL;
+		*value = final;
+		return finallen;
+	}
+
 	hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
 		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
 			continue;
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 50+ messages in thread

* Re: [PATCH 24/25] LSM: Add /proc attr entry for full LSM context
  2019-12-24 23:59   ` [PATCH 24/25] LSM: Add /proc attr entry for full LSM context Casey Schaufler
@ 2020-01-06 16:22     ` Stephen Smalley
  0 siblings, 0 replies; 50+ messages in thread
From: Stephen Smalley @ 2020-01-06 16:22 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul

On 12/24/19 6:59 PM, Casey Schaufler wrote:
> Add an entry /proc/.../attr/context which displays the full
> process security "context" in compound format:'
>          lsm1\0value\0lsm2\0value\0...
> This entry is not writable.

My takeaway from the earlier exchange with Simon on v12 was that we 
should either define a new LSM hook for /proc/pid/attr/context that is 
guaranteed to return a value in a consistent format with SO_PEERCONTEXT 
or fix AppArmor to return consistent results from its existing 
getprocattr hook (particularly with respect to the newline character).

> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> cc: linux-api@vger.kernel.org
> ---
>   fs/proc/base.c      |  1 +
>   security/security.c | 27 +++++++++++++++++++++++++++
>   2 files changed, 28 insertions(+)
> 
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index 950c200cb9ad..d13c2cf50e4b 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -2653,6 +2653,7 @@ static const struct pid_entry attr_dir_stuff[] = {
>   	ATTR(NULL, "keycreate",		0666),
>   	ATTR(NULL, "sockcreate",	0666),
>   	ATTR(NULL, "display",		0666),
> +	ATTR(NULL, "context",		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 80539dfd0245..e94de64e114c 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2099,6 +2099,10 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
>   				char **value)
>   {
>   	struct security_hook_list *hp;
> +	char *final = NULL;
> +	char *cp;
> +	int rc = 0;
> +	int finallen = 0;
>   	int display = lsm_task_display(current);
>   	int slot = 0;
>   
> @@ -2126,6 +2130,29 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
>   		return -ENOMEM;
>   	}
>   
> +	if (!strcmp(name, "context")) {
> +		hlist_for_each_entry(hp, &security_hook_heads.getprocattr,
> +				     list) {
> +			rc = hp->hook.getprocattr(p, "current", &cp);
> +			if (rc == -EINVAL || rc == -ENOPROTOOPT)
> +				continue;
> +			if (rc < 0) {
> +				kfree(final);
> +				return rc;
> +			}
> +			rc = append_ctx(&final, &finallen, hp->lsmid->lsm,
> +					cp, rc);
> +			if (rc < 0) {
> +				kfree(final);
> +				return rc;
> +			}
> +		}
> +		if (final == NULL)
> +			return -EINVAL;
> +		*value = final;
> +		return finallen;
> +	}
> +
>   	hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
>   		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
>   			continue;
> 


^ permalink raw reply	[flat|nested] 50+ messages in thread

* [PATCH v13 25/25] AppArmor: Remove the exclusive flag
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
                     ` (23 preceding siblings ...)
  2019-12-24 23:59   ` [PATCH 24/25] LSM: Add /proc attr entry for full LSM context Casey Schaufler
@ 2019-12-24 23:59   ` Casey Schaufler
  2020-01-03 18:53     ` Casey Schaufler
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2019-12-24 23:59 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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
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 34edfd29c32f..402a919190fd 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1112,22 +1112,6 @@ static int apparmor_socket_getpeersec_stream(struct socket *sock, char **optval,
 	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
@@ -1231,8 +1215,6 @@ 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),
@@ -1901,7 +1883,7 @@ 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] 50+ messages in thread

* [PATCH v13 26/25] Audit: Multiple LSM support in audit rules
  2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
@ 2020-01-03 18:53     ` Casey Schaufler
  2019-12-24 23:59   ` [PATCH v13 02/25] LSM: Create and manage the lsmblob data structure Casey Schaufler
                       ` (24 subsequent siblings)
  25 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2020-01-03 18:53 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: keescook, john.johansen, penguin-kernel, paul, sds, linux-audit,
	linux-integrity, Mimi Zohar

With multiple possible security modules supporting audit rule
it is necessary to keep separate data for each module in the
audit rules. This affects IMA as well, as it re-uses the audit
rule list mechanisms.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-integrity@vger.kernel.org
Cc: linux-audit@redhat.com
---
 include/linux/audit.h               |  4 +++-
 include/linux/security.h            |  8 +++----
 kernel/auditfilter.c                | 26 +++++++++++----------
 kernel/auditsc.c                    | 12 +++++-----
 security/integrity/ima/ima_policy.c | 36 +++++++++++++++++++----------
 security/security.c                 | 34 +++++++++++++++++++++++----
 6 files changed, 80 insertions(+), 40 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 2ce0e8da3922..d4213c471801 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -11,6 +11,7 @@
 
 #include <linux/sched.h>
 #include <linux/ptrace.h>
+#include <linux/security.h>
 #include <uapi/linux/audit.h>
 
 #define AUDIT_INO_UNSET ((unsigned long)-1)
@@ -64,8 +65,9 @@ struct audit_field {
 		kuid_t			uid;
 		kgid_t			gid;
 		struct {
+			bool		lsm_isset;
 			char		*lsm_str;
-			void		*lsm_rule;
+			void		*lsm_rules[LSMBLOB_ENTRIES];
 		};
 	};
 	u32				op;
diff --git a/include/linux/security.h b/include/linux/security.h
index 26967055a002..0bf71dd74a9c 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1887,8 +1887,8 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer)
 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(struct lsmblob *blob, u32 field, u32 op,
-			      void *lsmrule);
-void security_audit_rule_free(void *lsmrule);
+			      void **lsmrule);
+void security_audit_rule_free(void **lsmrule);
 
 #else
 
@@ -1904,12 +1904,12 @@ static inline int security_audit_rule_known(struct audit_krule *krule)
 }
 
 static inline int security_audit_rule_match(struct lsmblob *blob, u32 field,
-					    u32 op, void *lsmrule)
+					    u32 op, void **lsmrule)
 {
 	return 0;
 }
 
-static inline void security_audit_rule_free(void *lsmrule)
+static inline void security_audit_rule_free(void **lsmrule)
 { }
 
 #endif /* CONFIG_SECURITY */
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index bf28bb599b6d..0f351d1f6ef9 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -74,7 +74,7 @@ static void audit_free_lsm_field(struct audit_field *f)
 	case AUDIT_OBJ_LEV_LOW:
 	case AUDIT_OBJ_LEV_HIGH:
 		kfree(f->lsm_str);
-		security_audit_rule_free(f->lsm_rule);
+		security_audit_rule_free(f->lsm_rules);
 	}
 }
 
@@ -517,7 +517,7 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 			entry->rule.buflen += f->val;
 
 			err = security_audit_rule_init(f->type, f->op, str,
-						       (void **)&f->lsm_rule);
+						       f->lsm_rules);
 			/* Keep currently invalid fields around in case they
 			 * become valid after a policy reload. */
 			if (err == -EINVAL) {
@@ -528,8 +528,10 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 			if (err) {
 				kfree(str);
 				goto exit_free;
-			} else
+			} else {
+				f->lsm_isset = true;
 				f->lsm_str = str;
+			}
 			break;
 		case AUDIT_WATCH:
 			str = audit_unpack_string(&bufp, &remain, f->val);
@@ -767,7 +769,7 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
 	return 0;
 }
 
-/* Duplicate LSM field information.  The lsm_rule is opaque, so must be
+/* Duplicate LSM field information.  The lsm_rules is opaque, so must be
  * re-initialized. */
 static inline int audit_dupe_lsm_field(struct audit_field *df,
 					   struct audit_field *sf)
@@ -781,9 +783,9 @@ static inline int audit_dupe_lsm_field(struct audit_field *df,
 		return -ENOMEM;
 	df->lsm_str = lsm_str;
 
-	/* our own (refreshed) copy of lsm_rule */
+	/* our own (refreshed) copy of lsm_rules */
 	ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
-				       (void **)&df->lsm_rule);
+				       df->lsm_rules);
 	/* Keep currently invalid fields around in case they
 	 * become valid after a policy reload. */
 	if (ret == -EINVAL) {
@@ -835,7 +837,7 @@ struct audit_entry *audit_dupe_rule(struct audit_krule *old)
 	new->tree = old->tree;
 	memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
 
-	/* deep copy this information, updating the lsm_rule fields, because
+	/* deep copy this information, updating the lsm_rules fields, because
 	 * the originals will all be freed when the old rule is freed. */
 	for (i = 0; i < fcount; i++) {
 		switch (new->fields[i].type) {
@@ -1354,11 +1356,11 @@ int audit_filter(int msgtype, unsigned int listtype)
 			case AUDIT_SUBJ_TYPE:
 			case AUDIT_SUBJ_SEN:
 			case AUDIT_SUBJ_CLR:
-				if (f->lsm_rule) {
+				if (f->lsm_isset) {
 					security_task_getsecid(current, &blob);
 					result = security_audit_rule_match(
 							&blob, f->type,
-							f->op, f->lsm_rule);
+							f->op, f->lsm_rules);
 				}
 				break;
 			case AUDIT_EXE:
@@ -1385,7 +1387,7 @@ int audit_filter(int msgtype, unsigned int listtype)
 	return ret;
 }
 
-static int update_lsm_rule(struct audit_krule *r)
+static int update_lsm_rules(struct audit_krule *r)
 {
 	struct audit_entry *entry = container_of(r, struct audit_entry, rule);
 	struct audit_entry *nentry;
@@ -1417,7 +1419,7 @@ static int update_lsm_rule(struct audit_krule *r)
 	return err;
 }
 
-/* This function will re-initialize the lsm_rule field of all applicable rules.
+/* This function will re-initialize the lsm_rules field of all applicable rules.
  * It will traverse the filter lists serarching for rules that contain LSM
  * specific filter fields.  When such a rule is found, it is copied, the
  * LSM field is re-initialized, and the old rule is replaced with the
@@ -1432,7 +1434,7 @@ int audit_update_lsm_rules(void)
 
 	for (i = 0; i < AUDIT_NR_FILTERS; i++) {
 		list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
-			int res = update_lsm_rule(r);
+			int res = update_lsm_rules(r);
 			if (!err)
 				err = res;
 		}
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 28fea2e73040..b9f81ef64c39 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -638,7 +638,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 			   match for now to avoid losing information that
 			   may be wanted.   An error message will also be
 			   logged upon error */
-			if (f->lsm_rule) {
+			if (f->lsm_isset) {
 				if (need_sid) {
 					security_task_getsecid(tsk, &blob);
 					need_sid = 0;
@@ -646,7 +646,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 				result = security_audit_rule_match(&blob,
 								   f->type,
 								   f->op,
-								   f->lsm_rule);
+								   f->lsm_rules);
 			}
 			break;
 		case AUDIT_OBJ_USER:
@@ -656,21 +656,21 @@ static int audit_filter_rules(struct task_struct *tsk,
 		case AUDIT_OBJ_LEV_HIGH:
 			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
 			   also applies here */
-			if (f->lsm_rule) {
+			if (f->lsm_isset) {
 				/* Find files that match */
 				if (name) {
 					result = security_audit_rule_match(
 								&name->oblob,
 								f->type,
 								f->op,
-								f->lsm_rule);
+								f->lsm_rules);
 				} else if (ctx) {
 					list_for_each_entry(n, &ctx->names_list, list) {
 						if (security_audit_rule_match(
 								&n->oblob,
 								f->type,
 								f->op,
-								f->lsm_rule)) {
+								f->lsm_rules)) {
 							++result;
 							break;
 						}
@@ -681,7 +681,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 					break;
 				if (security_audit_rule_match(&ctx->ipc.oblob,
 							      f->type, f->op,
-							      f->lsm_rule))
+							      f->lsm_rules))
 					++result;
 			}
 			break;
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 1c617ae74558..227993b8422d 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -74,7 +74,7 @@ struct ima_rule_entry {
 	bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */
 	int pcr;
 	struct {
-		void *rule;	/* LSM file metadata specific */
+		void *rules[LSMBLOB_ENTRIES];
 		void *args_p;	/* audit value */
 		int type;	/* audit type */
 	} lsm[MAX_LSM_RULES];
@@ -82,6 +82,16 @@ struct ima_rule_entry {
 	struct ima_template_desc *template;
 };
 
+static inline bool ima_lsm_isset(void *rules[])
+{
+	int i;
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++)
+		if (rules[i])
+			return true;
+	return false;
+}
+
 /*
  * Without LSM specific knowledge, the default policy can only be
  * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner
@@ -252,9 +262,11 @@ __setup("ima_appraise_tcb", default_appraise_policy_setup);
 static void ima_lsm_free_rule(struct ima_rule_entry *entry)
 {
 	int i;
+	int r;
 
 	for (i = 0; i < MAX_LSM_RULES; i++) {
-		kfree(entry->lsm[i].rule);
+		for (r = 0; r < LSMBLOB_ENTRIES; r++)
+			kfree(entry->lsm[i].rules[r]);
 		kfree(entry->lsm[i].args_p);
 	}
 	kfree(entry);
@@ -277,7 +289,7 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)
 	memset(nentry->lsm, 0, sizeof_field(struct ima_rule_entry, lsm));
 
 	for (i = 0; i < MAX_LSM_RULES; i++) {
-		if (!entry->lsm[i].rule)
+		if (!ima_lsm_isset(entry->lsm[i].rules))
 			continue;
 
 		nentry->lsm[i].type = entry->lsm[i].type;
@@ -289,7 +301,7 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)
 		result = security_filter_rule_init(nentry->lsm[i].type,
 						   Audit_equal,
 						   nentry->lsm[i].args_p,
-						   &nentry->lsm[i].rule);
+						   nentry->lsm[i].rules);
 		if (result == -EINVAL)
 			pr_warn("ima: rule for LSM \'%d\' is undefined\n",
 				entry->lsm[i].type);
@@ -329,7 +341,7 @@ static void ima_lsm_update_rules(void)
 	list_for_each_entry_safe(entry, e, &ima_policy_rules, list) {
 		needs_update = 0;
 		for (i = 0; i < MAX_LSM_RULES; i++) {
-			if (entry->lsm[i].rule) {
+			if (ima_lsm_isset(entry->lsm[i].rules)) {
 				needs_update = 1;
 				break;
 			}
@@ -415,7 +427,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 		int rc = 0;
 		struct lsmblob blob;
 
-		if (!rule->lsm[i].rule)
+		if (!ima_lsm_isset(rule->lsm[i].rules))
 			continue;
 
 		switch (i) {
@@ -426,7 +438,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 			rc = security_filter_rule_match(&blob,
 							rule->lsm[i].type,
 							Audit_equal,
-							rule->lsm[i].rule);
+							rule->lsm[i].rules);
 			break;
 		case LSM_SUBJ_USER:
 		case LSM_SUBJ_ROLE:
@@ -434,7 +446,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 			rc = security_filter_rule_match(&blob,
 							rule->lsm[i].type,
 							Audit_equal,
-							rule->lsm[i].rule);
+							rule->lsm[i].rules);
 		default:
 			break;
 		}
@@ -811,7 +823,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
 {
 	int result;
 
-	if (entry->lsm[lsm_rule].rule)
+	if (ima_lsm_isset(entry->lsm[lsm_rule].rules))
 		return -EINVAL;
 
 	entry->lsm[lsm_rule].args_p = match_strdup(args);
@@ -822,8 +834,8 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
 	result = security_filter_rule_init(entry->lsm[lsm_rule].type,
 					   Audit_equal,
 					   entry->lsm[lsm_rule].args_p,
-					   &entry->lsm[lsm_rule].rule);
-	if (!entry->lsm[lsm_rule].rule) {
+					   entry->lsm[lsm_rule].rules);
+	if (!ima_lsm_isset(entry->lsm[lsm_rule].rules)) {
 		kfree(entry->lsm[lsm_rule].args_p);
 		return -EINVAL;
 	}
@@ -1470,7 +1482,7 @@ int ima_policy_show(struct seq_file *m, void *v)
 	}
 
 	for (i = 0; i < MAX_LSM_RULES; i++) {
-		if (entry->lsm[i].rule) {
+		if (ima_lsm_isset(entry->lsm[i].rules)) {
 			switch (i) {
 			case LSM_OBJ_USER:
 				seq_printf(m, pt(Opt_obj_user),
diff --git a/security/security.c b/security/security.c
index e94de64e114c..4be490512ed2 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2831,7 +2831,24 @@ int security_key_getsecurity(struct key *key, char **_buffer)
 
 int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
 {
-	return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule);
+	struct security_hook_list *hp;
+	bool one_is_good = false;
+	int rc = 0;
+	int trc;
+
+	hlist_for_each_entry(hp, &security_hook_heads.audit_rule_init, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		trc = hp->hook.audit_rule_init(field, op, rulestr,
+					       &lsmrule[hp->lsmid->slot]);
+		if (trc == 0)
+			one_is_good = true;
+		else
+			rc = trc;
+	}
+	if (one_is_good)
+		return 0;
+	return rc;
 }
 
 int security_audit_rule_known(struct audit_krule *krule)
@@ -2839,13 +2856,19 @@ int security_audit_rule_known(struct audit_krule *krule)
 	return call_int_hook(audit_rule_known, 0, krule);
 }
 
-void security_audit_rule_free(void *lsmrule)
+void security_audit_rule_free(void **lsmrule)
 {
-	call_void_hook(audit_rule_free, lsmrule);
+	struct security_hook_list *hp;
+
+	hlist_for_each_entry(hp, &security_hook_heads.audit_rule_free, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		hp->hook.audit_rule_free(lsmrule[hp->lsmid->slot]);
+	}
 }
 
 int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
-			      void *lsmrule)
+			      void **lsmrule)
 {
 	struct security_hook_list *hp;
 	int rc;
@@ -2854,7 +2877,8 @@ int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
 		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
 			continue;
 		rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
-					       field, op, lsmrule);
+					       field, op,
+					       &lsmrule[hp->lsmid->slot]);
 		if (rc != 0)
 			return rc;
 	}
-- 
2.20.1



^ permalink raw reply related	[flat|nested] 50+ messages in thread

* [PATCH v13 26/25] Audit: Multiple LSM support in audit rules
@ 2020-01-03 18:53     ` Casey Schaufler
  0 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2020-01-03 18:53 UTC (permalink / raw)
  To: casey.schaufler, jmorris, linux-security-module, selinux
  Cc: john.johansen, Mimi Zohar, linux-audit, linux-integrity, sds

With multiple possible security modules supporting audit rule
it is necessary to keep separate data for each module in the
audit rules. This affects IMA as well, as it re-uses the audit
rule list mechanisms.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-integrity@vger.kernel.org
Cc: linux-audit@redhat.com
---
 include/linux/audit.h               |  4 +++-
 include/linux/security.h            |  8 +++----
 kernel/auditfilter.c                | 26 +++++++++++----------
 kernel/auditsc.c                    | 12 +++++-----
 security/integrity/ima/ima_policy.c | 36 +++++++++++++++++++----------
 security/security.c                 | 34 +++++++++++++++++++++++----
 6 files changed, 80 insertions(+), 40 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 2ce0e8da3922..d4213c471801 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -11,6 +11,7 @@
 
 #include <linux/sched.h>
 #include <linux/ptrace.h>
+#include <linux/security.h>
 #include <uapi/linux/audit.h>
 
 #define AUDIT_INO_UNSET ((unsigned long)-1)
@@ -64,8 +65,9 @@ struct audit_field {
 		kuid_t			uid;
 		kgid_t			gid;
 		struct {
+			bool		lsm_isset;
 			char		*lsm_str;
-			void		*lsm_rule;
+			void		*lsm_rules[LSMBLOB_ENTRIES];
 		};
 	};
 	u32				op;
diff --git a/include/linux/security.h b/include/linux/security.h
index 26967055a002..0bf71dd74a9c 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1887,8 +1887,8 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer)
 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(struct lsmblob *blob, u32 field, u32 op,
-			      void *lsmrule);
-void security_audit_rule_free(void *lsmrule);
+			      void **lsmrule);
+void security_audit_rule_free(void **lsmrule);
 
 #else
 
@@ -1904,12 +1904,12 @@ static inline int security_audit_rule_known(struct audit_krule *krule)
 }
 
 static inline int security_audit_rule_match(struct lsmblob *blob, u32 field,
-					    u32 op, void *lsmrule)
+					    u32 op, void **lsmrule)
 {
 	return 0;
 }
 
-static inline void security_audit_rule_free(void *lsmrule)
+static inline void security_audit_rule_free(void **lsmrule)
 { }
 
 #endif /* CONFIG_SECURITY */
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index bf28bb599b6d..0f351d1f6ef9 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -74,7 +74,7 @@ static void audit_free_lsm_field(struct audit_field *f)
 	case AUDIT_OBJ_LEV_LOW:
 	case AUDIT_OBJ_LEV_HIGH:
 		kfree(f->lsm_str);
-		security_audit_rule_free(f->lsm_rule);
+		security_audit_rule_free(f->lsm_rules);
 	}
 }
 
@@ -517,7 +517,7 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 			entry->rule.buflen += f->val;
 
 			err = security_audit_rule_init(f->type, f->op, str,
-						       (void **)&f->lsm_rule);
+						       f->lsm_rules);
 			/* Keep currently invalid fields around in case they
 			 * become valid after a policy reload. */
 			if (err == -EINVAL) {
@@ -528,8 +528,10 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 			if (err) {
 				kfree(str);
 				goto exit_free;
-			} else
+			} else {
+				f->lsm_isset = true;
 				f->lsm_str = str;
+			}
 			break;
 		case AUDIT_WATCH:
 			str = audit_unpack_string(&bufp, &remain, f->val);
@@ -767,7 +769,7 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
 	return 0;
 }
 
-/* Duplicate LSM field information.  The lsm_rule is opaque, so must be
+/* Duplicate LSM field information.  The lsm_rules is opaque, so must be
  * re-initialized. */
 static inline int audit_dupe_lsm_field(struct audit_field *df,
 					   struct audit_field *sf)
@@ -781,9 +783,9 @@ static inline int audit_dupe_lsm_field(struct audit_field *df,
 		return -ENOMEM;
 	df->lsm_str = lsm_str;
 
-	/* our own (refreshed) copy of lsm_rule */
+	/* our own (refreshed) copy of lsm_rules */
 	ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
-				       (void **)&df->lsm_rule);
+				       df->lsm_rules);
 	/* Keep currently invalid fields around in case they
 	 * become valid after a policy reload. */
 	if (ret == -EINVAL) {
@@ -835,7 +837,7 @@ struct audit_entry *audit_dupe_rule(struct audit_krule *old)
 	new->tree = old->tree;
 	memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
 
-	/* deep copy this information, updating the lsm_rule fields, because
+	/* deep copy this information, updating the lsm_rules fields, because
 	 * the originals will all be freed when the old rule is freed. */
 	for (i = 0; i < fcount; i++) {
 		switch (new->fields[i].type) {
@@ -1354,11 +1356,11 @@ int audit_filter(int msgtype, unsigned int listtype)
 			case AUDIT_SUBJ_TYPE:
 			case AUDIT_SUBJ_SEN:
 			case AUDIT_SUBJ_CLR:
-				if (f->lsm_rule) {
+				if (f->lsm_isset) {
 					security_task_getsecid(current, &blob);
 					result = security_audit_rule_match(
 							&blob, f->type,
-							f->op, f->lsm_rule);
+							f->op, f->lsm_rules);
 				}
 				break;
 			case AUDIT_EXE:
@@ -1385,7 +1387,7 @@ int audit_filter(int msgtype, unsigned int listtype)
 	return ret;
 }
 
-static int update_lsm_rule(struct audit_krule *r)
+static int update_lsm_rules(struct audit_krule *r)
 {
 	struct audit_entry *entry = container_of(r, struct audit_entry, rule);
 	struct audit_entry *nentry;
@@ -1417,7 +1419,7 @@ static int update_lsm_rule(struct audit_krule *r)
 	return err;
 }
 
-/* This function will re-initialize the lsm_rule field of all applicable rules.
+/* This function will re-initialize the lsm_rules field of all applicable rules.
  * It will traverse the filter lists serarching for rules that contain LSM
  * specific filter fields.  When such a rule is found, it is copied, the
  * LSM field is re-initialized, and the old rule is replaced with the
@@ -1432,7 +1434,7 @@ int audit_update_lsm_rules(void)
 
 	for (i = 0; i < AUDIT_NR_FILTERS; i++) {
 		list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
-			int res = update_lsm_rule(r);
+			int res = update_lsm_rules(r);
 			if (!err)
 				err = res;
 		}
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 28fea2e73040..b9f81ef64c39 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -638,7 +638,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 			   match for now to avoid losing information that
 			   may be wanted.   An error message will also be
 			   logged upon error */
-			if (f->lsm_rule) {
+			if (f->lsm_isset) {
 				if (need_sid) {
 					security_task_getsecid(tsk, &blob);
 					need_sid = 0;
@@ -646,7 +646,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 				result = security_audit_rule_match(&blob,
 								   f->type,
 								   f->op,
-								   f->lsm_rule);
+								   f->lsm_rules);
 			}
 			break;
 		case AUDIT_OBJ_USER:
@@ -656,21 +656,21 @@ static int audit_filter_rules(struct task_struct *tsk,
 		case AUDIT_OBJ_LEV_HIGH:
 			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
 			   also applies here */
-			if (f->lsm_rule) {
+			if (f->lsm_isset) {
 				/* Find files that match */
 				if (name) {
 					result = security_audit_rule_match(
 								&name->oblob,
 								f->type,
 								f->op,
-								f->lsm_rule);
+								f->lsm_rules);
 				} else if (ctx) {
 					list_for_each_entry(n, &ctx->names_list, list) {
 						if (security_audit_rule_match(
 								&n->oblob,
 								f->type,
 								f->op,
-								f->lsm_rule)) {
+								f->lsm_rules)) {
 							++result;
 							break;
 						}
@@ -681,7 +681,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 					break;
 				if (security_audit_rule_match(&ctx->ipc.oblob,
 							      f->type, f->op,
-							      f->lsm_rule))
+							      f->lsm_rules))
 					++result;
 			}
 			break;
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 1c617ae74558..227993b8422d 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -74,7 +74,7 @@ struct ima_rule_entry {
 	bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */
 	int pcr;
 	struct {
-		void *rule;	/* LSM file metadata specific */
+		void *rules[LSMBLOB_ENTRIES];
 		void *args_p;	/* audit value */
 		int type;	/* audit type */
 	} lsm[MAX_LSM_RULES];
@@ -82,6 +82,16 @@ struct ima_rule_entry {
 	struct ima_template_desc *template;
 };
 
+static inline bool ima_lsm_isset(void *rules[])
+{
+	int i;
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++)
+		if (rules[i])
+			return true;
+	return false;
+}
+
 /*
  * Without LSM specific knowledge, the default policy can only be
  * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner
@@ -252,9 +262,11 @@ __setup("ima_appraise_tcb", default_appraise_policy_setup);
 static void ima_lsm_free_rule(struct ima_rule_entry *entry)
 {
 	int i;
+	int r;
 
 	for (i = 0; i < MAX_LSM_RULES; i++) {
-		kfree(entry->lsm[i].rule);
+		for (r = 0; r < LSMBLOB_ENTRIES; r++)
+			kfree(entry->lsm[i].rules[r]);
 		kfree(entry->lsm[i].args_p);
 	}
 	kfree(entry);
@@ -277,7 +289,7 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)
 	memset(nentry->lsm, 0, sizeof_field(struct ima_rule_entry, lsm));
 
 	for (i = 0; i < MAX_LSM_RULES; i++) {
-		if (!entry->lsm[i].rule)
+		if (!ima_lsm_isset(entry->lsm[i].rules))
 			continue;
 
 		nentry->lsm[i].type = entry->lsm[i].type;
@@ -289,7 +301,7 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)
 		result = security_filter_rule_init(nentry->lsm[i].type,
 						   Audit_equal,
 						   nentry->lsm[i].args_p,
-						   &nentry->lsm[i].rule);
+						   nentry->lsm[i].rules);
 		if (result == -EINVAL)
 			pr_warn("ima: rule for LSM \'%d\' is undefined\n",
 				entry->lsm[i].type);
@@ -329,7 +341,7 @@ static void ima_lsm_update_rules(void)
 	list_for_each_entry_safe(entry, e, &ima_policy_rules, list) {
 		needs_update = 0;
 		for (i = 0; i < MAX_LSM_RULES; i++) {
-			if (entry->lsm[i].rule) {
+			if (ima_lsm_isset(entry->lsm[i].rules)) {
 				needs_update = 1;
 				break;
 			}
@@ -415,7 +427,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 		int rc = 0;
 		struct lsmblob blob;
 
-		if (!rule->lsm[i].rule)
+		if (!ima_lsm_isset(rule->lsm[i].rules))
 			continue;
 
 		switch (i) {
@@ -426,7 +438,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 			rc = security_filter_rule_match(&blob,
 							rule->lsm[i].type,
 							Audit_equal,
-							rule->lsm[i].rule);
+							rule->lsm[i].rules);
 			break;
 		case LSM_SUBJ_USER:
 		case LSM_SUBJ_ROLE:
@@ -434,7 +446,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 			rc = security_filter_rule_match(&blob,
 							rule->lsm[i].type,
 							Audit_equal,
-							rule->lsm[i].rule);
+							rule->lsm[i].rules);
 		default:
 			break;
 		}
@@ -811,7 +823,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
 {
 	int result;
 
-	if (entry->lsm[lsm_rule].rule)
+	if (ima_lsm_isset(entry->lsm[lsm_rule].rules))
 		return -EINVAL;
 
 	entry->lsm[lsm_rule].args_p = match_strdup(args);
@@ -822,8 +834,8 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
 	result = security_filter_rule_init(entry->lsm[lsm_rule].type,
 					   Audit_equal,
 					   entry->lsm[lsm_rule].args_p,
-					   &entry->lsm[lsm_rule].rule);
-	if (!entry->lsm[lsm_rule].rule) {
+					   entry->lsm[lsm_rule].rules);
+	if (!ima_lsm_isset(entry->lsm[lsm_rule].rules)) {
 		kfree(entry->lsm[lsm_rule].args_p);
 		return -EINVAL;
 	}
@@ -1470,7 +1482,7 @@ int ima_policy_show(struct seq_file *m, void *v)
 	}
 
 	for (i = 0; i < MAX_LSM_RULES; i++) {
-		if (entry->lsm[i].rule) {
+		if (ima_lsm_isset(entry->lsm[i].rules)) {
 			switch (i) {
 			case LSM_OBJ_USER:
 				seq_printf(m, pt(Opt_obj_user),
diff --git a/security/security.c b/security/security.c
index e94de64e114c..4be490512ed2 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2831,7 +2831,24 @@ int security_key_getsecurity(struct key *key, char **_buffer)
 
 int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
 {
-	return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule);
+	struct security_hook_list *hp;
+	bool one_is_good = false;
+	int rc = 0;
+	int trc;
+
+	hlist_for_each_entry(hp, &security_hook_heads.audit_rule_init, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		trc = hp->hook.audit_rule_init(field, op, rulestr,
+					       &lsmrule[hp->lsmid->slot]);
+		if (trc == 0)
+			one_is_good = true;
+		else
+			rc = trc;
+	}
+	if (one_is_good)
+		return 0;
+	return rc;
 }
 
 int security_audit_rule_known(struct audit_krule *krule)
@@ -2839,13 +2856,19 @@ int security_audit_rule_known(struct audit_krule *krule)
 	return call_int_hook(audit_rule_known, 0, krule);
 }
 
-void security_audit_rule_free(void *lsmrule)
+void security_audit_rule_free(void **lsmrule)
 {
-	call_void_hook(audit_rule_free, lsmrule);
+	struct security_hook_list *hp;
+
+	hlist_for_each_entry(hp, &security_hook_heads.audit_rule_free, list) {
+		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+			continue;
+		hp->hook.audit_rule_free(lsmrule[hp->lsmid->slot]);
+	}
 }
 
 int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
-			      void *lsmrule)
+			      void **lsmrule)
 {
 	struct security_hook_list *hp;
 	int rc;
@@ -2854,7 +2877,8 @@ int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
 		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
 			continue;
 		rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
-					       field, op, lsmrule);
+					       field, op,
+					       &lsmrule[hp->lsmid->slot]);
 		if (rc != 0)
 			return rc;
 	}
-- 
2.20.1

^ permalink raw reply related	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 26/25] Audit: Multiple LSM support in audit rules
  2020-01-03 18:53     ` Casey Schaufler
  (?)
@ 2020-01-09 16:33     ` Mimi Zohar
  2020-01-10 19:40         ` Casey Schaufler
  -1 siblings, 1 reply; 50+ messages in thread
From: Mimi Zohar @ 2020-01-09 16:33 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul, sds, linux-audit,
	linux-integrity

Hi Casey,

On Fri, 2020-01-03 at 10:53 -0800, Casey Schaufler wrote:
> With multiple possible security modules supporting audit rule
> it is necessary to keep separate data for each module in the
> audit rules. This affects IMA as well, as it re-uses the audit
> rule list mechanisms.

While reviewing this patch, I realized there was a bug in the base IMA
code.  With Janne's bug fix, that he just posted, I think this patch
can now be simplified.

My main concern is the number of warning messages that will be
generated.  Any time a new LSM policy is loaded, the labels will be
re-evaulated whether or not they are applicable to the particular LSM,
causing unnecessary warnings.

Mimi

^ permalink raw reply	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 26/25] Audit: Multiple LSM support in audit rules
  2020-01-09 16:33     ` Mimi Zohar
@ 2020-01-10 19:40         ` Casey Schaufler
  0 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2020-01-10 19:40 UTC (permalink / raw)
  To: Mimi Zohar, casey.schaufler, jmorris, linux-security-module, selinux
  Cc: keescook, john.johansen, penguin-kernel, paul, sds, linux-audit,
	linux-integrity, Casey Schaufler

On 1/9/2020 8:33 AM, Mimi Zohar wrote:
> Hi Casey,
>
> On Fri, 2020-01-03 at 10:53 -0800, Casey Schaufler wrote:
>> With multiple possible security modules supporting audit rule
>> it is necessary to keep separate data for each module in the
>> audit rules. This affects IMA as well, as it re-uses the audit
>> rule list mechanisms.
> While reviewing this patch, I realized there was a bug in the base IMA
> code.  With Janne's bug fix, that he just posted, I think this patch
> can now be simplified.

How and when do you plan to get Janne's fix in? It's looking like
stacking won't be in for 5.6.

> My main concern is the number of warning messages that will be
> generated.  Any time a new LSM policy is loaded, the labels will be
> re-evaulated whether or not they are applicable to the particular LSM,
> causing unnecessary warnings.

Uhg. 

>
> Mimi
>

^ permalink raw reply	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 26/25] Audit: Multiple LSM support in audit rules
@ 2020-01-10 19:40         ` Casey Schaufler
  0 siblings, 0 replies; 50+ messages in thread
From: Casey Schaufler @ 2020-01-10 19:40 UTC (permalink / raw)
  To: Mimi Zohar, casey.schaufler, jmorris, linux-security-module, selinux
  Cc: john.johansen, linux-audit, linux-integrity, sds

On 1/9/2020 8:33 AM, Mimi Zohar wrote:
> Hi Casey,
>
> On Fri, 2020-01-03 at 10:53 -0800, Casey Schaufler wrote:
>> With multiple possible security modules supporting audit rule
>> it is necessary to keep separate data for each module in the
>> audit rules. This affects IMA as well, as it re-uses the audit
>> rule list mechanisms.
> While reviewing this patch, I realized there was a bug in the base IMA
> code.  With Janne's bug fix, that he just posted, I think this patch
> can now be simplified.

How and when do you plan to get Janne's fix in? It's looking like
stacking won't be in for 5.6.

> My main concern is the number of warning messages that will be
> generated.  Any time a new LSM policy is loaded, the labels will be
> re-evaulated whether or not they are applicable to the particular LSM,
> causing unnecessary warnings.

Uhg. 

>
> Mimi
>


--
Linux-audit mailing list
Linux-audit@redhat.com
https://www.redhat.com/mailman/listinfo/linux-audit

^ permalink raw reply	[flat|nested] 50+ messages in thread

* Re: [PATCH v13 26/25] Audit: Multiple LSM support in audit rules
  2020-01-10 19:40         ` Casey Schaufler
  (?)
@ 2020-01-12 15:37         ` Mimi Zohar
  -1 siblings, 0 replies; 50+ messages in thread
From: Mimi Zohar @ 2020-01-12 15:37 UTC (permalink / raw)
  To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
	selinux
  Cc: keescook, john.johansen, penguin-kernel, paul, sds, linux-audit,
	linux-integrity

On Fri, 2020-01-10 at 11:40 -0800, Casey Schaufler wrote:
> On 1/9/2020 8:33 AM, Mimi Zohar wrote:
> > Hi Casey,
> >
> > On Fri, 2020-01-03 at 10:53 -0800, Casey Schaufler wrote:
> >> With multiple possible security modules supporting audit rule
> >> it is necessary to keep separate data for each module in the
> >> audit rules. This affects IMA as well, as it re-uses the audit
> >> rule list mechanisms.
> > While reviewing this patch, I realized there was a bug in the base IMA
> > code.  With Janne's bug fix, that he just posted, I think this patch
> > can now be simplified.
> 
> How and when do you plan to get Janne's fix in? It's looking like
> stacking won't be in for 5.6.

The patch is now in the next-integrity-testing branch.  We'll see how
it goes.

> 
> > My main concern is the number of warning messages that will be
> > generated.  Any time a new LSM policy is loaded, the labels will be
> > re-evaulated whether or not they are applicable to the particular LSM,
> > causing unnecessary warnings.
> 
> Uhg.


^ permalink raw reply	[flat|nested] 50+ messages in thread

end of thread, other threads:[~2020-01-12 15:37 UTC | newest]

Thread overview: 50+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <20191224235939.7483-1-casey.ref@schaufler-ca.com>
2019-12-24 23:59 ` [PATCH v13 00/25] LSM: Module stacking for AppArmor Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 01/25] LSM: Infrastructure management of the sock security Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 02/25] LSM: Create and manage the lsmblob data structure Casey Schaufler
2019-12-25 20:34     ` Mickaël Salaün
2019-12-24 23:59   ` [PATCH v13 03/25] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
2019-12-31 13:13     ` Mimi Zohar
2020-01-02 23:36       ` Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 04/25] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 05/25] net: Prepare UDS for security module stacking Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 06/25] Use lsmblob in security_secctx_to_secid Casey Schaufler
2020-01-07 17:45     ` Stephen Smalley
2019-12-24 23:59   ` [PATCH v13 07/25] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 08/25] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 09/25] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
2020-01-07 17:53     ` Stephen Smalley
2019-12-24 23:59   ` [PATCH v13 10/25] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 11/25] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 12/25] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 13/25] LSM: Specify which LSM to display Casey Schaufler
2020-01-07 19:02     ` Stephen Smalley
2019-12-24 23:59   ` [PATCH v13 14/25] LSM: Ensure the correct LSM context releaser Casey Schaufler
2020-01-07 19:16     ` Stephen Smalley
2019-12-24 23:59   ` [PATCH v13 15/25] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2020-01-06 16:15     ` Stephen Smalley
2019-12-24 23:59   ` [PATCH v13 16/25] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
2020-01-07 19:23     ` Stephen Smalley
2019-12-24 23:59   ` [PATCH v13 17/25] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 18/25] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 19/25] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
2020-01-07 19:25     ` Stephen Smalley
2020-01-07 21:58       ` Casey Schaufler
2020-01-09 14:34     ` Stephen Smalley
2019-12-24 23:59   ` [PATCH v13 20/25] LSM: Verify LSM display sanity in binder Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 21/25] Audit: Add subj_LSM fields when necessary Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 22/25] Audit: Include object data for all security modules Casey Schaufler
2019-12-24 23:59   ` [PATCH v13 23/25] NET: Add SO_PEERCONTEXT for multiple LSMs Casey Schaufler
2020-01-06 17:15     ` Stephen Smalley
2020-01-06 17:29       ` Simon McVittie
2020-01-06 18:03         ` Casey Schaufler
2020-01-06 18:45           ` Stephen Smalley
2020-01-06 18:43         ` Stephen Smalley
2019-12-24 23:59   ` [PATCH 24/25] LSM: Add /proc attr entry for full LSM context Casey Schaufler
2020-01-06 16:22     ` Stephen Smalley
2019-12-24 23:59   ` [PATCH v13 25/25] AppArmor: Remove the exclusive flag Casey Schaufler
2020-01-03 18:53   ` [PATCH v13 26/25] Audit: Multiple LSM support in audit rules Casey Schaufler
2020-01-03 18:53     ` Casey Schaufler
2020-01-09 16:33     ` Mimi Zohar
2020-01-10 19:40       ` Casey Schaufler
2020-01-10 19:40         ` Casey Schaufler
2020-01-12 15:37         ` Mimi Zohar

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