[PATCH v14 00/23] LSM: Module stacking for AppArmor

[PATCH v14 00/23] LSM: Module stacking for AppArmor

[Casey Schaufler]

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

v14: Rebase to 5.5-rc5
     Incorporate feedback from v13
     - Use an array of audit rules (patch 0002)
     - Significant change, removed Acks (patch 0002)
     - Remove unneeded include (patch 0013)
     - Use context.len correctly (patch 0015)
     - Reorder code to be more sensible (patch 0016)
     - Drop SO_PEERCONTEXT as it's not needed yet (patch 0023)

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.

Patch 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 Patch 0018.

Patch 0019 adds checks to the binder hooks which verify
that if both ends of a transaction use the same "display".

Patches 0020-0021 add addition data to the audit records
to identify the LSM specific data for all active modules.

Patch 0022 adds a new interfaces for getting the
compound security contexts.

Finally, with all interference on the AppArmor hooks
removed, Patch 0023 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-rc5-v14

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---

[PATCH v14 01/23] LSM: Infrastructure management of the sock security

[Casey Schaufler]

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;
 	}
-- 
2.24.1

[PATCH v14 02/23] LSM: Create and manage the lsmblob data structure.

[Casey Schaufler]

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.

The audit rules data is expanded to use an array of
security module data rather than a single instance.
Because IMA uses the audit rule functions it is
affected as well.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/audit.h               |  4 +-
 include/linux/lsm_hooks.h           | 12 ++++-
 include/linux/security.h            | 66 ++++++++++++++++++++++++--
 kernel/auditfilter.c                | 27 ++++++-----
 kernel/auditsc.c                    | 12 ++---
 security/apparmor/lsm.c             |  7 ++-
 security/commoncap.c                |  7 ++-
 security/integrity/ima/ima_policy.c | 36 ++++++++++-----
 security/loadpin/loadpin.c          |  8 +++-
 security/lockdown/lockdown.c        |  7 ++-
 security/safesetid/lsm.c            |  8 +++-
 security/security.c                 | 72 ++++++++++++++++++++++++-----
 security/selinux/hooks.c            |  8 +++-
 security/smack/smack_lsm.c          |  7 ++-
 security/tomoyo/tomoyo.c            |  8 +++-
 security/yama/yama_lsm.c            |  7 ++-
 16 files changed, 239 insertions(+), 57 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index f9ceae57ca8d..8e1c759fd1ff 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/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..3422726268d2 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);
@@ -1779,8 +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);
-void security_audit_rule_free(void *lsmrule);
+int security_audit_rule_match(u32 secid, u32 field, u32 op, void **lsmrule);
+void security_audit_rule_free(void **lsmrule);
 
 #else
 
@@ -1796,12 +1854,12 @@ static inline int security_audit_rule_known(struct audit_krule *krule)
 }
 
 static inline int security_audit_rule_match(u32 secid, u32 field, u32 op,
-					    void *lsmrule)
+					    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 b0126e9c0743..3a44abf4fced 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) {
@@ -1353,10 +1355,11 @@ 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, &sid);
 					result = security_audit_rule_match(sid,
-						   f->type, f->op, f->lsm_rule);
+						   f->type, f->op,
+						   f->lsm_rules);
 				}
 				break;
 			case AUDIT_EXE:
@@ -1383,7 +1386,7 @@ 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;
@@ -1415,7 +1418,7 @@ 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
@@ -1430,7 +1433,7 @@ 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 4effe01ebbe2..0c239c29a9d5 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -638,14 +638,14 @@ 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, &sid);
 					need_sid = 0;
 				}
 				result = security_audit_rule_match(sid, f->type,
 								   f->op,
-								   f->lsm_rule);
+								   f->lsm_rules);
 			}
 			break;
 		case AUDIT_OBJ_USER:
@@ -655,21 +655,21 @@ 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->osid,
 								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->osid,
 								f->type,
 								f->op,
-								f->lsm_rule)) {
+								f->lsm_rules)) {
 							++result;
 							break;
 						}
@@ -680,7 +680,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 					break;
 				if (security_audit_rule_match(ctx->ipc.osid,
 							      f->type, f->op,
-							      f->lsm_rule))
+							      f->lsm_rules))
 					++result;
 			}
 			break;
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/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index ef8dfd47c7e3..808c2515fc6a 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;
 		u32 osid;
 
-		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(osid,
 							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(secid,
 							rule->lsm[i].type,
 							Audit_equal,
-							rule->lsm[i].rule);
+							rule->lsm[i].rules);
 		default:
 			break;
 		}
@@ -810,7 +822,7 @@ 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);
@@ -821,8 +833,8 @@ 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;
 	}
@@ -1469,7 +1481,7 @@ 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/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..214404a78db1 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);
 	}
@@ -2383,7 +2399,24 @@ 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)
@@ -2391,14 +2424,31 @@ 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(u32 secid, u32 field, u32 op, void *lsmrule)
+int security_audit_rule_match(u32 secid, 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(secid, field, op,
+					       &lsmrule[hp->lsmid->slot]);
+		if (rc)
+			return rc;
+	}
+	return 0;
 }
 #endif /* CONFIG_AUDIT */
 
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;
 }
-- 
2.24.1

Re: [PATCH v14 02/23] LSM: Create and manage the lsmblob data structure.

[Stephen Smalley]

On 1/23/20 7:22 PM, 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.
> 
> The audit rules data is expanded to use an array of
> security module data rather than a single instance.
> Because IMA uses the audit rule functions it is
> affected as well.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---

> 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)

You really want landlock merged, don't you?

[PATCH v14 03/23] LSM: Use lsmblob in security_audit_rule_match

[Casey Schaufler]

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                |  6 ++++--
 kernel/auditsc.c                    | 14 ++++++++++----
 security/integrity/ima/ima.h        |  4 ++--
 security/integrity/ima/ima_policy.c |  7 +++++--
 security/security.c                 |  8 +++++---
 6 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 3422726268d2..1988b728eb3a 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 3a44abf4fced..509eb21eff7f 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1327,6 +1327,7 @@ 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:
@@ -1357,8 +1358,9 @@ int audit_filter(int msgtype, unsigned int listtype)
 			case AUDIT_SUBJ_CLR:
 				if (f->lsm_isset) {
 					security_task_getsecid(current, &sid);
-					result = security_audit_rule_match(sid,
-						   f->type, f->op,
+					lsmblob_init(&blob, sid);
+					result = security_audit_rule_match(
+						   &blob, f->type, f->op,
 						   f->lsm_rules);
 				}
 				break;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 0c239c29a9d5..ef2f5e7eec7b 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_rules);
 			}
@@ -658,15 +661,17 @@ static int audit_filter_rules(struct task_struct *tsk,
 			if (f->lsm_isset) {
 				/* 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_rules);
 				} else if (ctx) {
 					list_for_each_entry(n, &ctx->names_list, list) {
+						lsmblob_init(&blob, name->osid);
 						if (security_audit_rule_match(
-								n->osid,
+								&blob,
 								f->type,
 								f->op,
 								f->lsm_rules)) {
@@ -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_rules))
 					++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 808c2515fc6a..27257af4a8cd 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -426,6 +426,7 @@ 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 (!ima_lsm_isset(rule->lsm[i].rules))
 			continue;
@@ -435,7 +436,8 @@ 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].rules);
@@ -443,7 +445,8 @@ 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].rules);
diff --git a/security/security.c b/security/security.c
index 214404a78db1..3a2529f36269 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.
@@ -2435,7 +2435,8 @@ void security_audit_rule_free(void **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)
 {
 	struct security_hook_list *hp;
 	int rc;
@@ -2443,7 +2444,8 @@ int security_audit_rule_match(u32 secid, u32 field, u32 op, void **lsmrule)
 	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(secid, field, op,
+		rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
+					       field, op,
 					       &lsmrule[hp->lsmid->slot]);
 		if (rc)
 			return rc;
-- 
2.24.1

[PATCH v14 04/23] LSM: Use lsmblob in security_kernel_act_as

[Casey Schaufler]

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 1988b728eb3a..4f01878ca5d8 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 9ed51b70ed80..490d72825aa5 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 3a2529f36269..f53805de4343 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)
-- 
2.24.1

[PATCH v14 05/23] net: Prepare UDS for security module stacking

[Casey Schaufler]

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 4f01878ca5d8..e53ff7eebcc5 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 f53805de4343..b7404bfc8938 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);
 
-- 
2.24.1

[PATCH v14 06/23] Use lsmblob in security_secctx_to_secid

[Casey Schaufler]

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 e53ff7eebcc5..5ad7cc8abd55 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 490d72825aa5..b41c2bbd357f 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 b7404bfc8938..c722cd495517 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);
 
-- 
2.24.1

Re: [PATCH v14 06/23] Use lsmblob in security_secctx_to_secid

[Stephen Smalley]

On 1/23/20 7:22 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>

I acked v13 of this patch and don't see any real change here, so:
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 e53ff7eebcc5..5ad7cc8abd55 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 490d72825aa5..b41c2bbd357f 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 b7404bfc8938..c722cd495517 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);
>   
> 

[PATCH v14 07/23] LSM: Use lsmblob in security_secid_to_secctx

[Casey Schaufler]

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 5ad7cc8abd55..556660941e5d 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 ef2f5e7eec7b..d6723c225c7e 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 6a1c8f1f6171..68c74c28eae9 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 c722cd495517..553d8e05be0c 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);
 
-- 
2.24.1

[PATCH v14 08/23] LSM: Use lsmblob in security_ipc_getsecid

[Casey Schaufler]

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 556660941e5d..5444302d2576 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 d6723c225c7e..032cdb603ac0 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 553d8e05be0c..9e80e55fad6a 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)
-- 
2.24.1

[PATCH v14 09/23] LSM: Use lsmblob in security_task_getsecid

[Casey Schaufler]

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>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
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 5444302d2576..9ad1d01fbbe4 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 509eb21eff7f..c9a46b78b932 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1326,7 +1326,6 @@ 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) {
@@ -1357,8 +1356,7 @@ int audit_filter(int msgtype, unsigned int listtype)
 			case AUDIT_SUBJ_SEN:
 			case AUDIT_SUBJ_CLR:
 				if (f->lsm_isset) {
-					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_rules);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 032cdb603ac0..3e5ccb7a46d1 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_isset) {
 				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 9e80e55fad6a..78185ddf232d 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);
 
-- 
2.24.1

[PATCH v14 10/23] LSM: Use lsmblob in security_inode_getsecid

[Casey Schaufler]

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 9ad1d01fbbe4..a3426c002644 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 3e5ccb7a46d1..b55e66c2451d 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 27257af4a8cd..6771c8c83105 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -425,7 +425,6 @@ 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 (!ima_lsm_isset(rule->lsm[i].rules))
@@ -435,8 +434,7 @@ 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 78185ddf232d..a4a1a7cccd4d 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)
-- 
2.24.1

[PATCH v14 11/23] LSM: Use lsmblob in security_cred_getsecid

[Casey Schaufler]

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 a3426c002644..0c6d37bd43cd 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 b55e66c2451d..d52ae228ad3d 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 a4a1a7cccd4d..100e55777426 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);
 
-- 
2.24.1

[PATCH v14 12/23] IMA: Change internal interfaces to use lsmblobs

[Casey Schaufler]

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 6771c8c83105..227993b8422d 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -380,7 +380,7 @@ 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;
@@ -443,7 +443,6 @@ 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,
@@ -487,7 +486,7 @@ 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
@@ -500,8 +499,9 @@ 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;
@@ -516,7 +516,7 @@ 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;
-- 
2.24.1

[PATCH v14 13/23] LSM: Specify which LSM to display

[Casey Schaufler]

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>

Acked-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                  | 167 ++++++++++++++++++++++++---
 security/selinux/hooks.c             |  11 ++
 security/selinux/include/classmap.h  |   2 +-
 security/smack/smack_lsm.c           |   7 ++
 8 files changed, 219 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 100e55777426..80ff19ba62e5 100644
--- a/security/security.c
+++ b/security/security.c
@@ -43,7 +43,14 @@ 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 +445,10 @@ 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 +468,7 @@ 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 +598,8 @@ 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 +608,15 @@ 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 +1572,26 @@ 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 +1988,110 @@ 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 +2111,15 @@ 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 +2129,15 @@ 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 +2145,14 @@ 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 +2277,15 @@ 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;
 
-- 
2.24.1

[PATCH v14 14/23] LSM: Ensure the correct LSM context releaser

[Casey Schaufler]

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>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
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 0c6d37bd43cd..0837a3594951 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 d52ae228ad3d..75bd9710790d 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 68c74c28eae9..3d18d6e2a7dd 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 80ff19ba62e5..9ed550d8221b 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2143,16 +2143,17 @@ 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);
 
-- 
2.24.1

[PATCH v14 15/23] LSM: Use lsmcontext in security_secid_to_secctx

[Casey Schaufler]

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                          | 35 ++++++++--------------
 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, 76 insertions(+), 120 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 0837a3594951..1e817130c112 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..f67187a84cb1 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1178,9 +1178,7 @@ 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)
@@ -1416,30 +1414,26 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		break;
 	}
 	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);
+		sig_data = kmalloc(sizeof(*sig_data) + context.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);
+				 sig_data, sizeof(*sig_data) + context.len);
 		kfree(sig_data);
 		break;
 	case AUDIT_TTY_GET: {
@@ -2061,26 +2055,23 @@ 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 75bd9710790d..f71d8f7521be 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 3d18d6e2a7dd..e2e6d4bf4ac3 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 9ed550d8221b..24e99716f6f2 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2108,18 +2108,22 @@ 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;
 }
-- 
2.24.1

[PATCH v14 16/23] LSM: Use lsmcontext in security_inode_getsecctx

[Casey Schaufler]

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 1e817130c112..f1a6c9ba907f 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 */
 
@@ -1359,7 +1359,8 @@ 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 24e99716f6f2..c2e5350e0f63 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2179,9 +2179,18 @@ 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);
 
-- 
2.24.1

[PATCH v14 17/23] LSM: security_secid_to_secctx in netlink netfilter

[Casey Schaufler]

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;
 }
 
-- 
2.24.1

[PATCH v14 18/23] NET: Store LSM netlabel data in a lsmblob

[Casey Schaufler]

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;
-- 
2.24.1

Re: [PATCH v14 18/23] NET: Store LSM netlabel data in a lsmblob

[Stephen Smalley]

On 1/23/20 7:23 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>

Similarly, I acked v13 of this patch and didn't see any real change here.

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;
> 

[PATCH v14 19/23] LSM: Verify LSM display sanity in binder

[Casey Schaufler]

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 c2e5350e0f63..6002075b4c8e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -737,9 +737,38 @@ 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);
 }
 
-- 
2.24.1

[PATCH v14 20/23] Audit: Add subj_LSM fields when necessary

[Casey Schaufler]

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 8e1c759fd1ff..d4213c471801 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -163,6 +163,7 @@ 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 f1a6c9ba907f..c18934f094a5 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);
@@ -1331,7 +1336,7 @@ 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 f67187a84cb1..c576ab810d86 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);
 }
 
@@ -1346,6 +1348,7 @@ 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;
@@ -1360,6 +1363,7 @@ 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;
 		}
@@ -1373,6 +1377,7 @@ 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: {
@@ -1408,6 +1413,7 @@ 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);
@@ -1416,7 +1422,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	case AUDIT_SIGNAL_INFO:
 		if (lsmblob_is_set(&audit_sig_lsm)) {
 			err = security_secid_to_secctx(&audit_sig_lsm,
-						       &context);
+						       &context, LSMBLOB_FIRST);
 			if (err)
 				return err;
 		}
@@ -1475,6 +1481,7 @@ 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;
 	}
@@ -2053,6 +2060,33 @@ 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;
@@ -2063,7 +2097,7 @@ 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;
@@ -2171,6 +2205,7 @@ 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);
 }
 
@@ -2221,6 +2256,7 @@ 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 c9a46b78b932..cd19dd995120 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1105,6 +1105,7 @@ 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 f71d8f7521be..68ae5fa843c1 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 e2e6d4bf4ac3..210aa5a84a08 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 6002075b4c8e..6a77c8b2ffbc 100644
--- a/security/security.c
+++ b/security/security.c
@@ -448,7 +448,31 @@ 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.
@@ -2137,13 +2161,32 @@ 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;
@@ -2154,7 +2197,7 @@ 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);
 
-- 
2.24.1

[PATCH v14 21/23] Audit: Include object data for all security modules

[Casey Schaufler]

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 | 106 ++++++++++++++++++++++++-----------------------
 2 files changed, 56 insertions(+), 54 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 68ae5fa843c1..7dab48661e31 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -659,7 +659,6 @@ static int audit_filter_rules(struct task_struct *tsk,
 			if (f->lsm_isset) {
 				/* Find files that match */
 				if (name) {
-					lsmblob_init(&blob, name->osid);
 					result = security_audit_rule_match(
 								&blob,
 								f->type,
@@ -667,7 +666,6 @@ static int audit_filter_rules(struct task_struct *tsk,
 								f->lsm_rules);
 				} else if (ctx) {
 					list_for_each_entry(n, &ctx->names_list, list) {
-						lsmblob_init(&blob, name->osid);
 						if (security_audit_rule_match(
 								&blob,
 								f->type,
@@ -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_rules))
 					++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;
 }
 
-- 
2.24.1

[PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Casey Schaufler]

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
---
 Documentation/security/lsm.rst | 14 ++++++++
 fs/proc/base.c                 |  1 +
 security/security.c            | 63 ++++++++++++++++++++++++++++++++++
 3 files changed, 78 insertions(+)

diff --git a/Documentation/security/lsm.rst b/Documentation/security/lsm.rst
index aadf47c808c0..a4979060f5d3 100644
--- a/Documentation/security/lsm.rst
+++ b/Documentation/security/lsm.rst
@@ -199,3 +199,17 @@ 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 an interface 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.
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 6a77c8b2ffbc..fdd0c85df89e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -722,6 +722,42 @@ 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.
  *
@@ -2041,6 +2077,10 @@ 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;
 
@@ -2068,6 +2108,29 @@ 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;
-- 
2.24.1

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Stephen Smalley]

On 1/23/20 7:23 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.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> Cc: linux-api@vger.kernel.org

As previously discussed, there are issues with AppArmor's implementation 
of getprocattr() particularly around the trailing newline that 
dbus-daemon and perhaps others would like to see go away in any new 
interface.  Hence, I don't think we should implement this new API using 
the existing getprocattr() hook lest it also be locked into the current 
behavior forever.

> ---
>   Documentation/security/lsm.rst | 14 ++++++++
>   fs/proc/base.c                 |  1 +
>   security/security.c            | 63 ++++++++++++++++++++++++++++++++++
>   3 files changed, 78 insertions(+)
> 
> diff --git a/Documentation/security/lsm.rst b/Documentation/security/lsm.rst
> index aadf47c808c0..a4979060f5d3 100644
> --- a/Documentation/security/lsm.rst
> +++ b/Documentation/security/lsm.rst
> @@ -199,3 +199,17 @@ 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 an interface 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.
> 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 6a77c8b2ffbc..fdd0c85df89e 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -722,6 +722,42 @@ 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.
>    *
> @@ -2041,6 +2077,10 @@ 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;
>   
> @@ -2068,6 +2108,29 @@ 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;
> 

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Stephen Smalley]

On 1/24/20 9:42 AM, Stephen Smalley wrote:
> On 1/23/20 7:23 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.
>>
>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>> Cc: linux-api@vger.kernel.org
> 
> As previously discussed, there are issues with AppArmor's implementation 
> of getprocattr() particularly around the trailing newline that 
> dbus-daemon and perhaps others would like to see go away in any new 
> interface.  Hence, I don't think we should implement this new API using 
> the existing getprocattr() hook lest it also be locked into the current 
> behavior forever.

Also, it would be good if whatever hook is introduced to support 
/proc/pid/attr/context could also be leveraged by the SO_PEERCONTEXT 
implementation in the future so that we are guaranteed a consistent 
result between the two interfaces, unlike the current situation for 
/proc/self/attr/current versus SO_PEERSEC.

> 
>> ---
>>   Documentation/security/lsm.rst | 14 ++++++++
>>   fs/proc/base.c                 |  1 +
>>   security/security.c            | 63 ++++++++++++++++++++++++++++++++++
>>   3 files changed, 78 insertions(+)
>>
>> diff --git a/Documentation/security/lsm.rst 
>> b/Documentation/security/lsm.rst
>> index aadf47c808c0..a4979060f5d3 100644
>> --- a/Documentation/security/lsm.rst
>> +++ b/Documentation/security/lsm.rst
>> @@ -199,3 +199,17 @@ 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 an interface 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.
>> 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 6a77c8b2ffbc..fdd0c85df89e 100644
>> --- a/security/security.c
>> +++ b/security/security.c
>> @@ -722,6 +722,42 @@ 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.
>>    *
>> @@ -2041,6 +2077,10 @@ 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;
>> @@ -2068,6 +2108,29 @@ 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;
>>
> 

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Casey Schaufler]

On 1/24/2020 8:20 AM, Stephen Smalley wrote:
> On 1/24/20 9:42 AM, Stephen Smalley wrote:
>> On 1/23/20 7:23 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.
>>>
>>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>>> Cc: linux-api@vger.kernel.org
>>
>> As previously discussed, there are issues with AppArmor's implementation of getprocattr() particularly around the trailing newline that dbus-daemon and perhaps others would like to see go away in any new interface.  Hence, I don't think we should implement this new API using the existing getprocattr() hook lest it also be locked into the current behavior forever.
>
> Also, it would be good if whatever hook is introduced to support /proc/pid/attr/context could also be leveraged by the SO_PEERCONTEXT implementation in the future so that we are guaranteed a consistent result between the two interfaces, unlike the current situation for /proc/self/attr/current versus SO_PEERSEC.

I don't believe that a new hook is necessary, and that introducing one
just to deal with a '\n' would be pedantic. We really have two rational
options. AppArmor could drop the '\n' from their "context". Or, we can
simply document that the /proc/pid/attr/context interface will trim any
trailing whitespace. I understand that this would be a break from the
notion that the LSM infrastructure does not constrain what a module uses
for its own data. On the other hand, we have been saying that "context"s
are strings, and ignoring trailing whitespace is usual behavior for
strings.



>
>>
>>> ---
>>>   Documentation/security/lsm.rst | 14 ++++++++
>>>   fs/proc/base.c                 |  1 +
>>>   security/security.c            | 63 ++++++++++++++++++++++++++++++++++
>>>   3 files changed, 78 insertions(+)
>>>
>>> diff --git a/Documentation/security/lsm.rst b/Documentation/security/lsm.rst
>>> index aadf47c808c0..a4979060f5d3 100644
>>> --- a/Documentation/security/lsm.rst
>>> +++ b/Documentation/security/lsm.rst
>>> @@ -199,3 +199,17 @@ 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 an interface 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.
>>> 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 6a77c8b2ffbc..fdd0c85df89e 100644
>>> --- a/security/security.c
>>> +++ b/security/security.c
>>> @@ -722,6 +722,42 @@ 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.
>>>    *
>>> @@ -2041,6 +2077,10 @@ 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;
>>> @@ -2068,6 +2108,29 @@ 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;
>>>
>>
>

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Stephen Smalley]

On 1/24/20 2:28 PM, Casey Schaufler wrote:
> On 1/24/2020 8:20 AM, Stephen Smalley wrote:
>> On 1/24/20 9:42 AM, Stephen Smalley wrote:
>>> On 1/23/20 7:23 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.
>>>>
>>>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>>>> Cc: linux-api@vger.kernel.org
>>>
>>> As previously discussed, there are issues with AppArmor's implementation of getprocattr() particularly around the trailing newline that dbus-daemon and perhaps others would like to see go away in any new interface.  Hence, I don't think we should implement this new API using the existing getprocattr() hook lest it also be locked into the current behavior forever.
>>
>> Also, it would be good if whatever hook is introduced to support /proc/pid/attr/context could also be leveraged by the SO_PEERCONTEXT implementation in the future so that we are guaranteed a consistent result between the two interfaces, unlike the current situation for /proc/self/attr/current versus SO_PEERSEC.
> 
> I don't believe that a new hook is necessary, and that introducing one
> just to deal with a '\n' would be pedantic. We really have two rational
> options. AppArmor could drop the '\n' from their "context". Or, we can
> simply document that the /proc/pid/attr/context interface will trim any
> trailing whitespace. I understand that this would be a break from the
> notion that the LSM infrastructure does not constrain what a module uses
> for its own data. On the other hand, we have been saying that "context"s
> are strings, and ignoring trailing whitespace is usual behavior for
> strings.

Well, you can either introduce a new common underlying hook for use by 
/proc/pid/attr/context and SO_PEERCONTEXT to produce the string that is 
to be returned to userspace (in order to guarantee consistency in format 
and allowing them to be directly compared, which I think is what the 
dbus maintainers wanted), or you can modify every security module to 
provide that guarantee in its existing getprocattr and getpeersec* hook 
functions (SELinux already provides this guarantee; Smack and AppArmor 
produce slightly different results with respect to \0 and/or \n), or you 
can have the framework trim the values it gets from the security modules 
before composing them.  But you need to do one of those things before 
this interface gets merged upstream.

Aside from the trailing newline and \0 issues, AppArmor also has a 
whitespace-separated (mode) field that may or may not be present in the 
contexts it presently returns, ala "/usr/sbin/cupsd (enforce)".  Not 
sure what they want for the new interfaces.

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Simon McVittie]

On Fri, 24 Jan 2020 at 15:16:36 -0500, Stephen Smalley wrote:
> Aside from the trailing newline and \0 issues, AppArmor also has a
> whitespace-separated (mode) field that may or may not be present in the
> contexts it presently returns, ala "/usr/sbin/cupsd (enforce)".

My understanding from last time I worked with AppArmor is that this
is genuinely part of the context, and whether it is present or absent
does not vary according to the kernel API used to access contexts.
AppArmor-specific higher-level APIs parse it into a label and an optional
mode, but LSM-agnostic user-space APIs (like the one in dbus) pass the
whole string through as-is.

(In practice it seems to be present if and only if the context is
something other than "unconfined", although I don't know offhand whether
that's an API guarantee.)

    smcv

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[John Johansen]

On 1/27/20 12:05 PM, Simon McVittie wrote:
> On Fri, 24 Jan 2020 at 15:16:36 -0500, Stephen Smalley wrote:
>> Aside from the trailing newline and \0 issues, AppArmor also has a
>> whitespace-separated (mode) field that may or may not be present in the
>> contexts it presently returns, ala "/usr/sbin/cupsd (enforce)".
> 
> My understanding from last time I worked with AppArmor is that this
> is genuinely part of the context, and whether it is present or absent
> does not vary according to the kernel API used to access contexts.
> AppArmor-specific higher-level APIs parse it into a label and an optional
> mode, but LSM-agnostic user-space APIs (like the one in dbus) pass the
> whole string through as-is.
> 
> (In practice it seems to be present if and only if the context is
> something other than "unconfined", although I don't know offhand whether
> that's an API guarantee.)
> 

Correct, currently it is always included unless the context is unconfined.
There is no guarantee that I am aware of beyond that is what the code
did in the past and so as to not break things we continue to do exactly
that.

The mode certainly does not need to be included in a newer interface.

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Casey Schaufler]

On 1/24/2020 12:16 PM, Stephen Smalley wrote:
> On 1/24/20 2:28 PM, Casey Schaufler wrote:
>> On 1/24/2020 8:20 AM, Stephen Smalley wrote:
>>> On 1/24/20 9:42 AM, Stephen Smalley wrote:
>>>> On 1/23/20 7:23 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.
>>>>>
>>>>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>>>>> Cc: linux-api@vger.kernel.org
>>>>
>>>> As previously discussed, there are issues with AppArmor's implementation of getprocattr() particularly around the trailing newline that dbus-daemon and perhaps others would like to see go away in any new interface.  Hence, I don't think we should implement this new API using the existing getprocattr() hook lest it also be locked into the current behavior forever.
>>>
>>> Also, it would be good if whatever hook is introduced to support /proc/pid/attr/context could also be leveraged by the SO_PEERCONTEXT implementation in the future so that we are guaranteed a consistent result between the two interfaces, unlike the current situation for /proc/self/attr/current versus SO_PEERSEC.
>>
>> I don't believe that a new hook is necessary, and that introducing one
>> just to deal with a '\n' would be pedantic. We really have two rational
>> options. AppArmor could drop the '\n' from their "context". Or, we can
>> simply document that the /proc/pid/attr/context interface will trim any
>> trailing whitespace. I understand that this would be a break from the
>> notion that the LSM infrastructure does not constrain what a module uses
>> for its own data. On the other hand, we have been saying that "context"s
>> are strings, and ignoring trailing whitespace is usual behavior for
>> strings.
>
> Well, you can either introduce a new common underlying hook for use by /proc/pid/attr/context and SO_PEERCONTEXT to produce the string that is to be returned to userspace (in order to guarantee consistency in format and allowing them to be directly compared, which I think is what the dbus maintainers wanted),

The getprocattr() hooks are already required to provide a nul terminated string.

The behavior of /proc/self/attr/current with regard to trailing whitespace or
the terminating nul is left to the security module.

The behavior of /proc/self/attr/context is new, and as such it can be defined
to be reasonable and consistent.

> or you can modify every security module to provide that guarantee in its existing getprocattr and getpeersec* hook functions (SELinux already provides this guarantee; Smack and AppArmor produce slightly different results with respect to \0 and/or \n), or you can have the framework trim the values it gets from the security modules before composing them.

Changing "every security module" turns out to be trivial, really.
The security_getprocattr() interface doesn't change, the getprocattr
hooks get a bool argument indicating if newlines are allowed, the
AppArmor code changes to check the bool and security_getprocattr()
sets to bool specially for the "context" case.

The getpeersec() interface use for SO_PEERCONTEXT isn't any more difficult.
The security modules are free to include a terminating nul or not in
the existing use case, but a bool can tell them what the behavior must
be when we get to that interface.

It's not like there are all that many security modules to bring in line
at this point. Establishing sane rules of behavior is overdue. With the
current set of new modules sniffing at the door it really is time to
tighten these up.

>   But you need to do one of those things before this interface gets merged upstream.
>
> Aside from the trailing newline and \0 issues, AppArmor also has a whitespace-separated (mode) field that may or may not be present in the contexts it presently returns, ala "/usr/sbin/cupsd (enforce)".  Not sure what they want for the new interfaces.

Using '\0' as a field terminator addresses that issue. That's a
primary motivator.

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Casey Schaufler]

On 1/24/2020 12:16 PM, Stephen Smalley wrote:
> On 1/24/20 2:28 PM, Casey Schaufler wrote:
>> On 1/24/2020 8:20 AM, Stephen Smalley wrote:
>>> On 1/24/20 9:42 AM, Stephen Smalley wrote:
>>>> On 1/23/20 7:23 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.
>>>>>
>>>>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>>>>> Cc: linux-api@vger.kernel.org
>>>>
>>>> As previously discussed, there are issues with AppArmor's implementation of getprocattr() particularly around the trailing newline that dbus-daemon and perhaps others would like to see go away in any new interface.  Hence, I don't think we should implement this new API using the existing getprocattr() hook lest it also be locked into the current behavior forever.
>>>
>>> Also, it would be good if whatever hook is introduced to support /proc/pid/attr/context could also be leveraged by the SO_PEERCONTEXT implementation in the future so that we are guaranteed a consistent result between the two interfaces, unlike the current situation for /proc/self/attr/current versus SO_PEERSEC.
>>
>> I don't believe that a new hook is necessary, and that introducing one
>> just to deal with a '\n' would be pedantic. We really have two rational
>> options. AppArmor could drop the '\n' from their "context". Or, we can
>> simply document that the /proc/pid/attr/context interface will trim any
>> trailing whitespace. I understand that this would be a break from the
>> notion that the LSM infrastructure does not constrain what a module uses
>> for its own data. On the other hand, we have been saying that "context"s
>> are strings, and ignoring trailing whitespace is usual behavior for
>> strings.
>
> Well, you can either introduce a new common underlying hook for use by /proc/pid/attr/context and SO_PEERCONTEXT to produce the string that is to be returned to userspace (in order to guarantee consistency in format and allowing them to be directly compared, which I think is what the dbus maintainers wanted), or you can modify every security module to provide that guarantee in its existing getprocattr and getpeersec* hook functions (SELinux already provides this guarantee; Smack and AppArmor produce slightly different results with respect to \0 and/or \n), or you can have the framework trim the values it gets from the security modules before composing them.  But you need to do one of those things before this interface gets merged upstream.
>
> Aside from the trailing newline and \0 issues, AppArmor also has a whitespace-separated (mode) field that may or may not be present in the contexts it presently returns, ala "/usr/sbin/cupsd (enforce)".  Not sure what they want for the new interfaces.
>
From c4085435215653b7c4d07a35a9df308120441d79 Mon Sep 17 00:00:00 2001
From: Casey Schaufler <casey@schaufler-ca.com>
Date: Fri, 31 Jan 2020 13:57:23 -0800
Subject: [PATCH v14] LSM: Move "context" format enforcement into security
 modules

Document in lsm_hooks.h what is expected of a security module that
supplies the "context" attribute.  Add handling of the "context"
attribute to SELinux, Smack and AppArmor security modules. The
AppArmor implementation provides a different string for "context"
than it does for other attributes to conform with the "context"
format.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h            |  6 ++++++
 security/apparmor/include/procattr.h |  2 +-
 security/apparmor/lsm.c              |  8 ++++++--
 security/apparmor/procattr.c         | 11 +++++++----
 security/security.c                  |  2 +-
 security/selinux/hooks.c             |  2 +-
 security/smack/smack_lsm.c           |  2 +-
 7 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 2bf82e1cf347..61977a33f2c3 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1321,6 +1321,12 @@
  *	@pages contains the number of pages.
  *	Return 0 if permission is granted.
  *
+ * @getprocattr:
+ *	Provide the named process attribute for display in special files in
+ *	the /proc/.../attr directory.  Attribute naming and the data displayed
+ *	is at the discretion of the security modules.  The exception is the
+ *	"context" attribute, which will contain the security context of the
+ *	task as a nul terminated text string without trailing whitespace.
  * @ismaclabel:
  *	Check if the extended attribute specified by @name
  *	represents a MAC label. Returns 1 if name is a MAC
diff --git a/security/apparmor/include/procattr.h b/security/apparmor/include/procattr.h
index 31689437e0e1..03dbfdb2f2c0 100644
--- a/security/apparmor/include/procattr.h
+++ b/security/apparmor/include/procattr.h
@@ -11,7 +11,7 @@
 #ifndef __AA_PROCATTR_H
 #define __AA_PROCATTR_H
 
-int aa_getprocattr(struct aa_label *label, char **string);
+int aa_getprocattr(struct aa_label *label, char **string, bool newline);
 int aa_setprocattr_changehat(char *args, size_t size, int flags);
 
 #endif /* __AA_PROCATTR_H */
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 37d003568e82..07729c28275e 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -593,6 +593,7 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
 	const struct cred *cred = get_task_cred(task);
 	struct aa_task_ctx *ctx = task_ctx(current);
 	struct aa_label *label = NULL;
+	bool newline = true;
 
 	if (strcmp(name, "current") == 0)
 		label = aa_get_newest_label(cred_label(cred));
@@ -600,11 +601,14 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
 		label = aa_get_newest_label(ctx->previous);
 	else if (strcmp(name, "exec") == 0 && ctx->onexec)
 		label = aa_get_newest_label(ctx->onexec);
-	else
+	else if (strcmp(name, "context") == 0) {
+		label = aa_get_newest_label(cred_label(cred));
+		newline = false;
+	} else
 		error = -EINVAL;
 
 	if (label)
-		error = aa_getprocattr(label, value);
+		error = aa_getprocattr(label, value, newline);
 
 	aa_put_label(label);
 	put_cred(cred);
diff --git a/security/apparmor/procattr.c b/security/apparmor/procattr.c
index c929bf4a3df1..1098bca3d0e4 100644
--- a/security/apparmor/procattr.c
+++ b/security/apparmor/procattr.c
@@ -20,6 +20,7 @@
  * aa_getprocattr - Return the profile information for @profile
  * @profile: the profile to print profile info about  (NOT NULL)
  * @string: Returns - string containing the profile info (NOT NULL)
+ * @newline: Should a newline be added to @string.
  *
  * Returns: length of @string on success else error on failure
  *
@@ -30,7 +31,7 @@
  *
  * Returns: size of string placed in @string else error code on failure
  */
-int aa_getprocattr(struct aa_label *label, char **string)
+int aa_getprocattr(struct aa_label *label, char **string, bool newline)
 {
 	struct aa_ns *ns = labels_ns(label);
 	struct aa_ns *current_ns = aa_get_current_ns();
@@ -60,11 +61,13 @@ int aa_getprocattr(struct aa_label *label, char **string)
 		return len;
 	}
 
-	(*string)[len] = '\n';
-	(*string)[len + 1] = 0;
+	if (newline) {
+		(*string)[len] = '\n';
+		(*string)[++len] = 0;
+	}
 
 	aa_put_ns(current_ns);
-	return len + 1;
+	return len;
 }
 
 /**
diff --git a/security/security.c b/security/security.c
index fdd0c85df89e..5a4d90256fd7 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2111,7 +2111,7 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
 	if (!strcmp(name, "context")) {
 		hlist_for_each_entry(hp, &security_hook_heads.getprocattr,
 				     list) {
-			rc = hp->hook.getprocattr(p, "current", &cp);
+			rc = hp->hook.getprocattr(p, "context", &cp);
 			if (rc == -EINVAL || rc == -ENOPROTOOPT)
 				continue;
 			if (rc < 0) {
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index cd4743331800..1f53a0c66a46 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6281,7 +6281,7 @@ static int selinux_getprocattr(struct task_struct *p,
 			goto bad;
 	}
 
-	if (!strcmp(name, "current"))
+	if (!strcmp(name, "current") || !strcmp(name, "context"))
 		sid = __tsec->sid;
 	else if (!strcmp(name, "prev"))
 		sid = __tsec->osid;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 9ce67e03ac49..834b6e886e7b 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3487,7 +3487,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value)
 	char *cp;
 	int slen;
 
-	if (strcmp(name, "current") != 0)
+	if (strcmp(name, "current") != 0 && strcmp(name, "context") != 0)
 		return -EINVAL;
 
 	cp = kstrdup(skp->smk_known, GFP_KERNEL);
-- 
2.24.1

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Stephen Smalley]

On 1/31/20 5:10 PM, Casey Schaufler wrote:
>  From c4085435215653b7c4d07a35a9df308120441d79 Mon Sep 17 00:00:00 2001
> From: Casey Schaufler <casey@schaufler-ca.com>
> Date: Fri, 31 Jan 2020 13:57:23 -0800
> Subject: [PATCH v14] LSM: Move "context" format enforcement into security
>   modules
> 
> Document in lsm_hooks.h what is expected of a security module that
> supplies the "context" attribute.  Add handling of the "context"
> attribute to SELinux, Smack and AppArmor security modules. The
> AppArmor implementation provides a different string for "context"
> than it does for other attributes to conform with the "context"
> format.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---
>   include/linux/lsm_hooks.h            |  6 ++++++
>   security/apparmor/include/procattr.h |  2 +-
>   security/apparmor/lsm.c              |  8 ++++++--
>   security/apparmor/procattr.c         | 11 +++++++----
>   security/security.c                  |  2 +-
>   security/selinux/hooks.c             |  2 +-
>   security/smack/smack_lsm.c           |  2 +-
>   7 files changed, 23 insertions(+), 10 deletions(-)
> 
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index 2bf82e1cf347..61977a33f2c3 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -1321,6 +1321,12 @@
>    *	@pages contains the number of pages.
>    *	Return 0 if permission is granted.
>    *
> + * @getprocattr:
> + *	Provide the named process attribute for display in special files in
> + *	the /proc/.../attr directory.  Attribute naming and the data displayed
> + *	is at the discretion of the security modules.  The exception is the
> + *	"context" attribute, which will contain the security context of the
> + *	task as a nul terminated text string without trailing whitespace.

I'd suggest something like the following instead:
* @getprocattr
*   Get the value of process attribute @name for task @p into a buffer
*   allocated by the security module and returned via @value.  The
*   caller will free the returned buffer via kfree.  The set of
*   attribute names is fixed by proc but the format of @value is up
*   to the security module authors except for the "context" attribute,
*   whose value is required to be a NUL-terminated printable ASCII
*   string without trailing whitespace.
*   @p the task whose attribute is being fetched
*   @name the name of the process attribute being fetched
*   @value set to point to the buffer containing the attribute value
*   Return the length of @value including the NUL on success, or -errno 
on error.

The printable ASCII bit is based on what the dbus maintainer requested 
in previous discussions.  The question of whether the terminating NUL 
should be included in the returned length was otherwise left ambiguous 
and inconsistent in your patch among the different security modules; if 
you prefer not including it in the length returned by the security 
modules, you'll need to adjust SELinux at least to not do so for "context".

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Stephen Smalley]

On 2/3/20 1:54 PM, Stephen Smalley wrote:
> I'd suggest something like the following instead:
> * @getprocattr
> *   Get the value of process attribute @name for task @p into a buffer
> *   allocated by the security module and returned via @value.  The
> *   caller will free the returned buffer via kfree.  The set of
> *   attribute names is fixed by proc but the format of @value is up
> *   to the security module authors except for the "context" attribute,
> *   whose value is required to be a NUL-terminated printable ASCII
> *   string without trailing whitespace.
> *   @p the task whose attribute is being fetched
> *   @name the name of the process attribute being fetched
> *   @value set to point to the buffer containing the attribute value
> *   Return the length of @value including the NUL on success, or -errno 
> on error.
> 
> The printable ASCII bit is based on what the dbus maintainer requested 
> in previous discussions.  The question of whether the terminating NUL 
> should be included in the returned length was otherwise left ambiguous 
> and inconsistent in your patch among the different security modules; if 
> you prefer not including it in the length returned by the security 
> modules, you'll need to adjust SELinux at least to not do so for "context".

BTW, I think the above guarantees with the exception of no trailing 
whitespace and whether the NUL byte is included or excluded from length 
are in reality also required for "current" (and SO_PEERSEC) or existing 
userspace will break.

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Casey Schaufler]

On 2/3/2020 11:37 AM, Stephen Smalley wrote:
> On 2/3/20 1:54 PM, Stephen Smalley wrote:
>> I'd suggest something like the following instead:
>> * @getprocattr
>> *   Get the value of process attribute @name for task @p into a buffer
>> *   allocated by the security module and returned via @value.  The
>> *   caller will free the returned buffer via kfree.  The set of
>> *   attribute names is fixed by proc but the format of @value is up
>> *   to the security module authors except for the "context" attribute,
>> *   whose value is required to be a NUL-terminated printable ASCII
>> *   string without trailing whitespace.
>> *   @p the task whose attribute is being fetched
>> *   @name the name of the process attribute being fetched
>> *   @value set to point to the buffer containing the attribute value
>> *   Return the length of @value including the NUL on success, or -errno on error.

I'm fine with either description, so I'll adopt yours.

>>
>> The printable ASCII bit is based on what the dbus maintainer requested in previous discussions.  The question of whether the terminating NUL should be included in the returned length was otherwise left ambiguous and inconsistent in your patch among the different security modules; if you prefer not including it in the length returned by the security modules, you'll need to adjust SELinux at least to not do so for "context".

append_ctx() is supposed to take the possibility that the module specific context string
may or may not include a trailing '\0' into account. Alas, I see a problem in the current
version for the "no trailing '\0'" case. On the other hand, with your proposed description
the trailing '\0' is required, so it's a matter of verifying that all modules providing
a "context" provide one that includes a trailing '\0' and return strlen()+1.

>
> BTW, I think the above guarantees with the exception of no trailing whitespace and whether the NUL byte is included or excluded from length are in reality also required for "current" (and SO_PEERSEC) or existing userspace will break.

The behavior of interfaces (e.g. "current", "exec") that are module defined
is only of concern with respect to to "display" behavior. If a security module
wants to provide a variable size binary blob in "current" I would object on
principle, but policy as I understand it has long been that if the authors want
to do that, it's their call. The "context" has a defined format, and it would
be up to the authors to come up with a printable ASCII representation of the
binary blob. If they care. They're not required to provide a "context".

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Stephen Smalley]

On 2/3/20 4:39 PM, Casey Schaufler wrote:
> On 2/3/2020 11:37 AM, Stephen Smalley wrote:
>> BTW, I think the above guarantees with the exception of no trailing whitespace and whether the NUL byte is included or excluded from length are in reality also required for "current" (and SO_PEERSEC) or existing userspace will break.
> 
> The behavior of interfaces (e.g. "current", "exec") that are module defined
> is only of concern with respect to to "display" behavior. If a security module
> wants to provide a variable size binary blob in "current" I would object on
> principle, but policy as I understand it has long been that if the authors want
> to do that, it's their call.

Doing so would break existing userspace (not just LSM-specific 
userspace), so I think it would be a deal breaker even for new security 
modules to move away from those guarantees for "current" at least. 
procps-ng (and I think procps before it) directly reads 
/proc/pid/attr/current and truncates at the first unprintable character. 
  systemd's sd-bus reads /proc/pid/attr/current directly and treats \n, 
\r, or \0 byte as terminators and truncated on first occurrence.  A 
variety of userspace code uses the value obtained from 
/proc/pid/attr/current and/or SO_PEERSEC as something that it can pass 
to printf-like functions using a %s specifier for inclusion in logs and 
audit messages.

> The "context" has a defined format, and it would
> be up to the authors to come up with a printable ASCII representation of the
> binary blob. If they care. They're not required to provide a "context".

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Casey Schaufler]

On 2/4/2020 5:37 AM, Stephen Smalley wrote:
> On 2/3/20 4:39 PM, Casey Schaufler wrote:
>> On 2/3/2020 11:37 AM, Stephen Smalley wrote:
>>> BTW, I think the above guarantees with the exception of no trailing whitespace and whether the NUL byte is included or excluded from length are in reality also required for "current" (and SO_PEERSEC) or existing userspace will break.
>>
>> The behavior of interfaces (e.g. "current", "exec") that are module defined
>> is only of concern with respect to to "display" behavior. If a security module
>> wants to provide a variable size binary blob in "current" I would object on
>> principle, but policy as I understand it has long been that if the authors want
>> to do that, it's their call.
>
> Doing so would break existing userspace (not just LSM-specific userspace), so I think it would be a deal breaker even for new security modules to move away from those guarantees for "current" at least. procps-ng (and I think procps before it) directly reads /proc/pid/attr/current and truncates at the first unprintable character. 

An user-space that makes invalid assumptions about an interface
can't implicitly define the behavior of that interface. You can't
declare that "current" is defined to be a string just because a
developer looked at how one security module uses it and coded the
application accordingly. You can't declare that "current" will
always be a SELinux context. That horse left the barn in 2007,
and there are still people writing code assuming that is what
they're getting.

If the sub-system maintainer, James Morris, is willing to state that
"current" must have a particular format that would be different.

> systemd's sd-bus reads /proc/pid/attr/current directly and treats \n, \r, or \0 byte as terminators and truncated on first occurrence.  A variety of userspace code uses the value obtained from /proc/pid/attr/current and/or SO_PEERSEC as something that it can pass to printf-like functions using a %s specifier for inclusion in logs and audit messages.

Yup. And so far no security module has been foolish enough to export
a binary blob in a /proc/.../attr interface. That doesn't mean that
the interface is defined as a string. It's certainly the convention,
but nowhere is it documented as a requirement.

That's why I'm putting in the effort to define the format for "context"
and SO_PEERCONTEXT. Interfaces at the LSM level need to be defined so as
to allow the underlying security modules to provide the information they
want in a way that is unambiguous and application non-hostile. The help
I've gotten from you and the rest of the reviewers over the life of this
effort has been extremely helpful, if not always easy to swallow.

>
>> The "context" has a defined format, and it would
>> be up to the authors to come up with a printable ASCII representation of the
>> binary blob. If they care. They're not required to provide a "context".
>
>

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Simon McVittie]

On Mon, 03 Feb 2020 at 13:54:45 -0500, Stephen Smalley wrote:
> The printable ASCII bit is based on what the dbus maintainer requested in
> previous discussions.

I thought in previous discussions, we had come to the conclusion that
I can't assume it's 7-bit ASCII. (If I *can* assume that for this new
API, that's even better.)

To be clear, when I say ASCII I mean a sequence of bytes != '\0' with
their high bit unset (x & 0x7f == x) and the obvious mapping to/from
Unicode (bytes '\1' to '\x7f' represent codepoints U+0001 to U+007F). Is
that the same thing you mean?

I thought the conclusion we had come to in previous conversations was
that the LSM context is what GLib calls a "bytestring", the same as
filenames and environment variables - an opaque sequence of bytes != '\0',
with no further guarantees, and no specified encoding or mapping to/from
Unicode (most likely some superset of ASCII like UTF-8 or Latin-1,
but nobody knows which one, and they could equally well be some binary
encoding with no Unicode meaning, as long as it avoids '\0').

If I can safely assume that a new kernel <-> user-space API is constrained
to UTF-8 or a UTF-8 subset like ASCII, then I can provide more friendly
APIs for user-space features built over it. If that isn't possible, the
next best thing is a "bytestring" like filenames, environment variables,
and most kernel <-> user-space strings in general.

    smcv

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Stephen Smalley]

On 2/10/20 6:56 AM, Simon McVittie wrote:
> On Mon, 03 Feb 2020 at 13:54:45 -0500, Stephen Smalley wrote:
>> The printable ASCII bit is based on what the dbus maintainer requested in
>> previous discussions.
> 
> I thought in previous discussions, we had come to the conclusion that
> I can't assume it's 7-bit ASCII. (If I *can* assume that for this new
> API, that's even better.)
> 
> To be clear, when I say ASCII I mean a sequence of bytes != '\0' with
> their high bit unset (x & 0x7f == x) and the obvious mapping to/from
> Unicode (bytes '\1' to '\x7f' represent codepoints U+0001 to U+007F). Is
> that the same thing you mean?

I mean the subset of 7-bit ASCII that satisfies isprint() using the "C" 
locale.  That is already true for SELinux with the existing interfaces. 
I can't necessarily speak for the others.

> I thought the conclusion we had come to in previous conversations was
> that the LSM context is what GLib calls a "bytestring", the same as
> filenames and environment variables - an opaque sequence of bytes != '\0',
> with no further guarantees, and no specified encoding or mapping to/from
> Unicode (most likely some superset of ASCII like UTF-8 or Latin-1,
> but nobody knows which one, and they could equally well be some binary
> encoding with no Unicode meaning, as long as it avoids '\0').
> 
> If I can safely assume that a new kernel <-> user-space API is constrained
> to UTF-8 or a UTF-8 subset like ASCII, then I can provide more friendly
> APIs for user-space features built over it. If that isn't possible, the
> next best thing is a "bytestring" like filenames, environment variables,
> and most kernel <-> user-space strings in general.
> 
>      smcv
> 

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Stephen Smalley]

On 2/10/20 8:25 AM, Stephen Smalley wrote:
> On 2/10/20 6:56 AM, Simon McVittie wrote:
>> On Mon, 03 Feb 2020 at 13:54:45 -0500, Stephen Smalley wrote:
>>> The printable ASCII bit is based on what the dbus maintainer 
>>> requested in
>>> previous discussions.
>>
>> I thought in previous discussions, we had come to the conclusion that
>> I can't assume it's 7-bit ASCII. (If I *can* assume that for this new
>> API, that's even better.)
>>
>> To be clear, when I say ASCII I mean a sequence of bytes != '\0' with
>> their high bit unset (x & 0x7f == x) and the obvious mapping to/from
>> Unicode (bytes '\1' to '\x7f' represent codepoints U+0001 to U+007F). Is
>> that the same thing you mean?
> 
> I mean the subset of 7-bit ASCII that satisfies isprint() using the "C" 
> locale.  That is already true for SELinux with the existing interfaces. 
> I can't necessarily speak for the others.

Looks like Smack labels are similarly restricted, per 
Documentation/admin-guide/LSM/Smack.rst.  So I guess the only one that 
is perhaps unclear is AppArmor, since its labels are typically derived 
from pathnames?  Can an AppArmor label returned via its getprocattr() 
hook be any legal pathname?

>> I thought the conclusion we had come to in previous conversations was
>> that the LSM context is what GLib calls a "bytestring", the same as
>> filenames and environment variables - an opaque sequence of bytes != 
>> '\0',
>> with no further guarantees, and no specified encoding or mapping to/from
>> Unicode (most likely some superset of ASCII like UTF-8 or Latin-1,
>> but nobody knows which one, and they could equally well be some binary
>> encoding with no Unicode meaning, as long as it avoids '\0').
>>
>> If I can safely assume that a new kernel <-> user-space API is 
>> constrained
>> to UTF-8 or a UTF-8 subset like ASCII, then I can provide more friendly
>> APIs for user-space features built over it. If that isn't possible, the
>> next best thing is a "bytestring" like filenames, environment variables,
>> and most kernel <-> user-space strings in general.
>>
>>      smcv
>>
> 

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Casey Schaufler]

On 2/10/2020 6:55 AM, Stephen Smalley wrote:
> On 2/10/20 8:25 AM, Stephen Smalley wrote:
>> On 2/10/20 6:56 AM, Simon McVittie wrote:
>>> On Mon, 03 Feb 2020 at 13:54:45 -0500, Stephen Smalley wrote:
>>>> The printable ASCII bit is based on what the dbus maintainer requested in
>>>> previous discussions.
>>>
>>> I thought in previous discussions, we had come to the conclusion that
>>> I can't assume it's 7-bit ASCII. (If I *can* assume that for this new
>>> API, that's even better.)
>>>
>>> To be clear, when I say ASCII I mean a sequence of bytes != '\0' with
>>> their high bit unset (x & 0x7f == x) and the obvious mapping to/from
>>> Unicode (bytes '\1' to '\x7f' represent codepoints U+0001 to U+007F). Is
>>> that the same thing you mean?
>>
>> I mean the subset of 7-bit ASCII that satisfies isprint() using the "C" locale.  That is already true for SELinux with the existing interfaces. I can't necessarily speak for the others.
>
> Looks like Smack labels are similarly restricted, per Documentation/admin-guide/LSM/Smack.rst.  So I guess the only one that is perhaps unclear is AppArmor, since its labels are typically derived from pathnames?  Can an AppArmor label returned via its getprocattr() hook be any legal pathname?

Because attr/context (and later, SO_PEERCONTEXT) are new interfaces
there is no need to exactly duplicate what is in attr/current (later
SO_PEERSEC). I already plan to omit the "mode" component of the
AppArmor data in the AppArmor hook, as was discussed earlier. I would
prefer ASCII, but if AppArmor needs bytestrings, that's what we'll
have to do.

>
>>> I thought the conclusion we had come to in previous conversations was
>>> that the LSM context is what GLib calls a "bytestring", the same as
>>> filenames and environment variables - an opaque sequence of bytes != '\0',
>>> with no further guarantees, and no specified encoding or mapping to/from
>>> Unicode (most likely some superset of ASCII like UTF-8 or Latin-1,
>>> but nobody knows which one, and they coould equally well be some binary
>>> encoding with no Unicode meaning, as long as it avoids '\0').
>>>
>>> If I can safely assume that a new kernel <-> user-space API is constrained
>>> to UTF-8 or a UTF-8 subset like ASCII, then I can provide more friendly
>>> APIs for user-space features built over it. If that isn't possible, the
>>> next best thing is a "bytestring" like filenames, environment variables,
>>> and most kernel <-> user-space strings in general.
>>>
>>>      smcv
>>>
>>
>

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[John Johansen]

On 2/10/20 10:32 AM, Casey Schaufler wrote:
> On 2/10/2020 6:55 AM, Stephen Smalley wrote:
>> On 2/10/20 8:25 AM, Stephen Smalley wrote:
>>> On 2/10/20 6:56 AM, Simon McVittie wrote:
>>>> On Mon, 03 Feb 2020 at 13:54:45 -0500, Stephen Smalley wrote:
>>>>> The printable ASCII bit is based on what the dbus maintainer requested in
>>>>> previous discussions.
>>>>
>>>> I thought in previous discussions, we had come to the conclusion that
>>>> I can't assume it's 7-bit ASCII. (If I *can* assume that for this new
>>>> API, that's even better.)
>>>>
>>>> To be clear, when I say ASCII I mean a sequence of bytes != '\0' with
>>>> their high bit unset (x & 0x7f == x) and the obvious mapping to/from
>>>> Unicode (bytes '\1' to '\x7f' represent codepoints U+0001 to U+007F). Is
>>>> that the same thing you mean?
>>>
>>> I mean the subset of 7-bit ASCII that satisfies isprint() using the "C" locale.  That is already true for SELinux with the existing interfaces. I can't necessarily speak for the others.
>>
>> Looks like Smack labels are similarly restricted, per Documentation/admin-guide/LSM/Smack.rst.  So I guess the only one that is perhaps unclear is AppArmor, since its labels are typically derived from pathnames?  Can an AppArmor label returned via its getprocattr() hook be any legal pathname?
> 
> Because attr/context (and later, SO_PEERCONTEXT) are new interfaces
> there is no need to exactly duplicate what is in attr/current (later
> SO_PEERSEC). I already plan to omit the "mode" component of the
> AppArmor data in the AppArmor hook, as was discussed earlier. I would
> prefer ASCII, but if AppArmor needs bytestrings, that's what we'll
> have to do.
> 

sadly, to not break userspace its a byte string because that is what the path based profile names are. AppArmor does support a more limited non path based profile name but I can't guarantee that is what userspace is using in policy.


>>
>>>> I thought the conclusion we had come to in previous conversations was
>>>> that the LSM context is what GLib calls a "bytestring", the same as
>>>> filenames and environment variables - an opaque sequence of bytes != '\0',
>>>> with no further guarantees, and no specified encoding or mapping to/from
>>>> Unicode (most likely some superset of ASCII like UTF-8 or Latin-1,
>>>> but nobody knows which one, and they coould equally well be some binary
>>>> encoding with no Unicode meaning, as long as it avoids '\0').
>>>>
>>>> If I can safely assume that a new kernel <-> user-space API is constrained
>>>> to UTF-8 or a UTF-8 subset like ASCII, then I can provide more friendly
>>>> APIs for user-space features built over it. If that isn't possible, the
>>>> next best thing is a "bytestring" like filenames, environment variables,
>>>> and most kernel <-> user-space strings in general.
>>>>
>>>>       smcv
>>>>
>>>
>>
> 

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Stephen Smalley]

On 2/10/20 2:00 PM, John Johansen wrote:
> On 2/10/20 10:32 AM, Casey Schaufler wrote:
>> Because attr/context (and later, SO_PEERCONTEXT) are new interfaces
>> there is no need to exactly duplicate what is in attr/current (later
>> SO_PEERSEC). I already plan to omit the "mode" component of the
>> AppArmor data in the AppArmor hook, as was discussed earlier. I would
>> prefer ASCII, but if AppArmor needs bytestrings, that's what we'll
>> have to do.
>>
> 
> sadly, to not break userspace its a byte string because that is what the 
> path based profile names are. AppArmor does support a more limited non 
> path based profile name but I can't guarantee that is what userspace is 
> using in policy.

Ok, so /proc/pid/attr/context and SO_PEERCONTEXT have to be defined as 
returning bytestrings.

So far we've talked about having AppArmor drop the trailing newline, be 
consistent with regard to whether the terminating NUL is included or 
excluded, and drop the mode field from what it returns for 
/proc/pid/attr/context and SO_PEERCONTEXT versus the current 
/proc/pid/attr/current and SO_PEERSEC.  Is that correct?

How do we envision a liblsm processing the value returned from 
/proc/pid/attr/context or SO_PEEERCONTEXT?  It can certainly split it up 
per LSM.  But can it then take the apparmor portion of the context and 
pass that to existing libapparmor interfaces without breakage?  Or will 
the changes to the format described above create issues there?

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[John Johansen]

On 2/11/20 7:59 AM, Stephen Smalley wrote:
> On 2/10/20 2:00 PM, John Johansen wrote:
>> On 2/10/20 10:32 AM, Casey Schaufler wrote:
>>> Because attr/context (and later, SO_PEERCONTEXT) are new interfaces
>>> there is no need to exactly duplicate what is in attr/current (later
>>> SO_PEERSEC). I already plan to omit the "mode" component of the
>>> AppArmor data in the AppArmor hook, as was discussed earlier. I would
>>> prefer ASCII, but if AppArmor needs bytestrings, that's what we'll
>>> have to do.
>>>
>>
>> sadly, to not break userspace its a byte string because that is what the path based profile names are. AppArmor does support a more limited non path based profile name but I can't guarantee that is what userspace is using in policy.
> 
> Ok, so /proc/pid/attr/context and SO_PEERCONTEXT have to be defined as returning bytestrings.
> 
> So far we've talked about having AppArmor drop the trailing newline, be consistent with regard to whether the terminating NUL is included or excluded, and drop the mode field from what it returns for /proc/pid/attr/context and SO_PEERCONTEXT versus the current /proc/pid/attr/current and SO_PEERSEC.  Is that correct?
> 
> How do we envision a liblsm processing the value returned from /proc/pid/attr/context or SO_PEEERCONTEXT?  It can certainly split it up per LSM.  But can it then take the apparmor portion of the context and pass that to existing libapparmor interfaces without breakage?  Or will the changes to the format described above create issues there?
> 
>
libapparmor can handle the changes. It does not require the mode string, currently anything unconfined does not include it, and we have already done experiments with dropping it in other cases. The trailing '\n' is handled conditionally so only if its there; this is well tested as the currently out of upstream af_unix socket mediation that is used by dbus does not include a trailing '\n' on the SO_PEERSEC.

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Casey Schaufler]

On 2/11/2020 9:58 AM, John Johansen wrote:
> On 2/11/20 7:59 AM, Stephen Smalley wrote:
>> On 2/10/20 2:00 PM, John Johansen wrote:
>>> On 2/10/20 10:32 AM, Casey Schaufler wrote:
>>>> Because attr/context (and later, SO_PEERCONTEXT) are new interfaces
>>>> there is no need to exactly duplicate what is in attr/current (later
>>>> SO_PEERSEC). I already plan to omit the "mode" component of the
>>>> AppArmor data in the AppArmor hook, as was discussed earlier. I would
>>>> prefer ASCII, but if AppArmor needs bytestrings, that's what we'll
>>>> have to do.
>>>>
>>>
>>> sadly, to not break userspace its a byte string because that is what the path based profile names are. AppArmor does support a more limited non path based profile name but I can't guarantee that is what userspace is using in policy.
>>
>> Ok, so /proc/pid/attr/context and SO_PEERCONTEXT have to be defined as returning bytestrings.
>>
>> So far we've talked about having AppArmor drop the trailing newline, be consistent with regard to whether the terminating NUL is included or excluded, and drop the mode field from what it returns for /proc/pid/attr/context and SO_PEERCONTEXT versus the current /proc/pid/attr/current and SO_PEERSEC.  Is that correct?
>>
>> How do we envision a liblsm processing the value returned from /proc/pid/attr/context or SO_PEEERCONTEXT?  

There hasn't been any serious thought put into liblsm. To date
there hasn't been an LSM level interface to worry about except
for /sys/kernel/security/lsm. My notions of what a liblsm ought
provide would seem archaic to most of the people here. I can make
proposals if there's a notion that liblsm makes sense.


>> It can certainly split it up per LSM.  But can it then take the apparmor portion of the context and pass that to existing libapparmor interfaces without breakage?  Or will the changes to the format described above create issues there?
>>
>>
> libapparmor can handle the changes. It does not require the mode string, currently anything unconfined does not include it, and we have already done experiments with dropping it in other cases. The trailing '\n' is handled conditionally so only if its there; this is well tested as the currently out of upstream af_unix socket mediation that is used by dbus does not include a trailing '\n' on the SO_PEERSEC.

So it doesn't seem that there would be significant difficulties
switching from "current" to "context". It won't be transparent,
but we're providing "display" to address that.

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[John Johansen]

On 2/11/20 10:35 AM, Casey Schaufler wrote:
> On 2/11/2020 9:58 AM, John Johansen wrote:
>> On 2/11/20 7:59 AM, Stephen Smalley wrote:
>>> On 2/10/20 2:00 PM, John Johansen wrote:
>>>> On 2/10/20 10:32 AM, Casey Schaufler wrote:
>>>>> Because attr/context (and later, SO_PEERCONTEXT) are new interfaces
>>>>> there is no need to exactly duplicate what is in attr/current (later
>>>>> SO_PEERSEC). I already plan to omit the "mode" component of the
>>>>> AppArmor data in the AppArmor hook, as was discussed earlier. I would
>>>>> prefer ASCII, but if AppArmor needs bytestrings, that's what we'll
>>>>> have to do.
>>>>>
>>>>
>>>> sadly, to not break userspace its a byte string because that is what the path based profile names are. AppArmor does support a more limited non path based profile name but I can't guarantee that is what userspace is using in policy.
>>>
>>> Ok, so /proc/pid/attr/context and SO_PEERCONTEXT have to be defined as returning bytestrings.
>>>
>>> So far we've talked about having AppArmor drop the trailing newline, be consistent with regard to whether the terminating NUL is included or excluded, and drop the mode field from what it returns for /proc/pid/attr/context and SO_PEERCONTEXT versus the current /proc/pid/attr/current and SO_PEERSEC.  Is that correct?
>>>
>>> How do we envision a liblsm processing the value returned from /proc/pid/attr/context or SO_PEEERCONTEXT?
> 
> There hasn't been any serious thought put into liblsm. To date
> there hasn't been an LSM level interface to worry about except
> for /sys/kernel/security/lsm. My notions of what a liblsm ought
> provide would seem archaic to most of the people here. I can make
> proposals if there's a notion that liblsm makes sense.
> 
> 
>>> It can certainly split it up per LSM.  But can it then take the apparmor portion of the context and pass that to existing libapparmor interfaces without breakage?  Or will the changes to the format described above create issues there?
>>>
>>>
>> libapparmor can handle the changes. It does not require the mode string, currently anything unconfined does not include it, and we have already done experiments with dropping it in other cases. The trailing '\n' is handled conditionally so only if its there; this is well tested as the currently out of upstream af_unix socket mediation that is used by dbus does not include a trailing '\n' on the SO_PEERSEC.
> 
> So it doesn't seem that there would be significant difficulties
> switching from "current" to "context". It won't be transparent,
> but we're providing "display" to address that.
> 
> 
right

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[John Johansen]

On 2/10/20 6:55 AM, Stephen Smalley wrote:
> On 2/10/20 8:25 AM, Stephen Smalley wrote:
>> On 2/10/20 6:56 AM, Simon McVittie wrote:
>>> On Mon, 03 Feb 2020 at 13:54:45 -0500, Stephen Smalley wrote:
>>>> The printable ASCII bit is based on what the dbus maintainer requested in
>>>> previous discussions.
>>>
>>> I thought in previous discussions, we had come to the conclusion that
>>> I can't assume it's 7-bit ASCII. (If I *can* assume that for this new
>>> API, that's even better.)
>>>
>>> To be clear, when I say ASCII I mean a sequence of bytes != '\0' with
>>> their high bit unset (x & 0x7f == x) and the obvious mapping to/from
>>> Unicode (bytes '\1' to '\x7f' represent codepoints U+0001 to U+007F). Is
>>> that the same thing you mean?
>>
>> I mean the subset of 7-bit ASCII that satisfies isprint() using the "C" locale.  That is already true for SELinux with the existing interfaces. I can't necessarily speak for the others.
> 
> Looks like Smack labels are similarly restricted, per Documentation/admin-guide/LSM/Smack.rst.  So I guess the only one that is perhaps unclear is AppArmor, since its labels are typically derived from pathnames?  Can an AppArmor label returned via its getprocattr() hook be any legal pathname?
> 

yes sadly, as much as I would like to depracate/remove it the pathname based profile names are a byte string. AppArmor supports a more restricted profile name and I have been trying to get people to move to it for 12 years with only limited success.

>>> I thought the conclusion we had come to in previous conversations was
>>> that the LSM context is what GLib calls a "bytestring", the same as
>>> filenames and environment variables - an opaque sequence of bytes != '\0',
>>> with no further guarantees, and no specified encoding or mapping to/from
>>> Unicode (most likely some superset of ASCII like UTF-8 or Latin-1,
>>> but nobody knows which one, and they could equally well be some binary
>>> encoding with no Unicode meaning, as long as it avoids '\0').
>>>
>>> If I can safely assume that a new kernel <-> user-space API is constrained
>>> to UTF-8 or a UTF-8 subset like ASCII, then I can provide more friendly
>>> APIs for user-space features built over it. If that isn't possible, the
>>> next best thing is a "bytestring" like filenames, environment variables,
>>> and most kernel <-> user-space strings in general.
>>>
>>>      smcv
>>>
>>
> 

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[John Johansen]

On 1/24/20 12:16 PM, Stephen Smalley wrote:
> On 1/24/20 2:28 PM, Casey Schaufler wrote:
>> On 1/24/2020 8:20 AM, Stephen Smalley wrote:
>>> On 1/24/20 9:42 AM, Stephen Smalley wrote:
>>>> On 1/23/20 7:23 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.
>>>>>
>>>>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>>>>> Cc: linux-api@vger.kernel.org
>>>>
>>>> As previously discussed, there are issues with AppArmor's implementation of getprocattr() particularly around the trailing newline that dbus-daemon and perhaps others would like to see go away in any new interface.  Hence, I don't think we should implement this new API using the existing getprocattr() hook lest it also be locked into the current behavior forever.
>>>
>>> Also, it would be good if whatever hook is introduced to support /proc/pid/attr/context could also be leveraged by the SO_PEERCONTEXT implementation in the future so that we are guaranteed a consistent result between the two interfaces, unlike the current situation for /proc/self/attr/current versus SO_PEERSEC.
>>
>> I don't believe that a new hook is necessary, and that introducing one
>> just to deal with a '\n' would be pedantic. We really have two rational
>> options. AppArmor could drop the '\n' from their "context". Or, we can
>> simply document that the /proc/pid/attr/context interface will trim any
>> trailing whitespace. I understand that this would be a break from the
>> notion that the LSM infrastructure does not constrain what a module uses
>> for its own data. On the other hand, we have been saying that "context"s
>> are strings, and ignoring trailing whitespace is usual behavior for
>> strings.
> 
> Well, you can either introduce a new common underlying hook for use by /proc/pid/attr/context and SO_PEERCONTEXT to produce the string that is to be returned to userspace (in order to guarantee consistency in format and allowing them to be directly compared, which I think is what the dbus maintainers wanted), or you can modify every security module to provide that guarantee in its existing getprocattr and getpeersec* hook functions (SELinux already provides this guarantee; Smack and AppArmor produce slightly different results with respect to \0 and/or \n), or you can have the framework trim the values it gets from the security modules before composing them.  But you need to do one of those things before this interface gets merged upstream.
> 
> Aside from the trailing newline and \0 issues, AppArmor also has a whitespace-separated (mode) field that may or may not be present in the contexts it presently returns, ala "/usr/sbin/cupsd (enforce)".  Not sure what they want for the new interfaces.
> 

It is not needed for the new interface. And if I could go back and remove it from the old interface I would.

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[Casey Schaufler]

On 2/3/2020 1:02 PM, John Johansen wrote:
> On 1/24/20 12:16 PM, Stephen Smalley wrote:
>> ...
>>
>> Aside from the trailing newline and \0 issues, AppArmor also has a whitespace-separated (mode) field that may or may not be present in the contexts it presently returns, ala "/usr/sbin/cupsd (enforce)".  Not sure what they want for the new interfaces.
>>
>
> It is not needed for the new interface. And if I could go back and remove it from the old interface I would.

So, what would the "context" for this case be? "/usr/sbin/cupsd" or "enforce"?

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[John Johansen]

On 2/3/20 1:43 PM, Casey Schaufler wrote:
> On 2/3/2020 1:02 PM, John Johansen wrote:
>> On 1/24/20 12:16 PM, Stephen Smalley wrote:
>>> ...
>>>
>>> Aside from the trailing newline and \0 issues, AppArmor also has a whitespace-separated (mode) field that may or may not be present in the contexts it presently returns, ala "/usr/sbin/cupsd (enforce)".  Not sure what they want for the new interfaces.
>>>
>>
>> It is not needed for the new interface. And if I could go back and remove it from the old interface I would.
> 
> So, what would the "context" for this case be? "/usr/sbin/cupsd" or "enforce"?
> 

"/usr/sbin/cupsd"

"enforce" is the profile mode which can be looked up separately using "/usr/sbin/cupsd" if it is really needed.

Re: [PATCH v14 22/23] LSM: Add /proc attr entry for full LSM context

[John Johansen]

On 1/24/20 11:28 AM, Casey Schaufler wrote:
> On 1/24/2020 8:20 AM, Stephen Smalley wrote:
>> On 1/24/20 9:42 AM, Stephen Smalley wrote:
>>> On 1/23/20 7:23 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.
>>>>
>>>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>>>> Cc: linux-api@vger.kernel.org
>>>
>>> As previously discussed, there are issues with AppArmor's implementation of getprocattr() particularly around the trailing newline that dbus-daemon and perhaps others would like to see go away in any new interface.  Hence, I don't think we should implement this new API using the existing getprocattr() hook lest it also be locked into the current behavior forever.
>>
>> Also, it would be good if whatever hook is introduced to support /proc/pid/attr/context could also be leveraged by the SO_PEERCONTEXT implementation in the future so that we are guaranteed a consistent result between the two interfaces, unlike the current situation for /proc/self/attr/current versus SO_PEERSEC.
> 
> I don't believe that a new hook is necessary, and that introducing one
> just to deal with a '\n' would be pedantic. We really have two rational
> options. AppArmor could drop the '\n' from their "context". Or, we can
> simply document that the /proc/pid/attr/context interface will trim any
> trailing whitespace. I understand that this would be a break from the
> notion that the LSM infrastructure does not constrain what a module uses
> for its own data. On the other hand, we have been saying that "context"s
> are strings, and ignoring trailing whitespace is usual behavior for
> strings.
> 
> 

AppArmor can drop the trailing '\n' it is not required. I would say it
could be dropped from /proc/pid/attr/current except there may be some
third party code that requires it.

[PATCH v14 23/23] AppArmor: Remove the exclusive flag

[Casey Schaufler]

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 16b992235c11..37d003568e82 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1120,22 +1120,6 @@ static int apparmor_socket_getpeersec_stream(struct socket *sock,
 	return error;
 }
 
-/**
- * apparmor_socket_getpeersec_dgram - get security label of packet
- * @sock: the peer socket
- * @skb: packet data
- * @secid: pointer to where to put the secid of the packet
- *
- * Sets the netlabel socket state on sk from parent
- */
-static int apparmor_socket_getpeersec_dgram(struct socket *sock,
-					    struct sk_buff *skb, u32 *secid)
-
-{
-	/* TODO: requires secid support */
-	return -ENOPROTOOPT;
-}
-
 /**
  * apparmor_sock_graft - Initialize newly created socket
  * @sk: child sock
@@ -1239,8 +1223,6 @@ 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),
@@ -1909,7 +1891,7 @@ 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,
-- 
2.24.1

Re: [PATCH v14 00/23] LSM: Module stacking for AppArmor

[Stephen Smalley]

On 1/23/20 7:22 PM, Casey Schaufler wrote:
> This patchset provides the changes required for
> the AppArmor security module to stack safely with any other.
> 
> v14: Rebase to 5.5-rc5
>       Incorporate feedback from v13
>       - Use an array of audit rules (patch 0002)
>       - Significant change, removed Acks (patch 0002)
>       - Remove unneeded include (patch 0013)
>       - Use context.len correctly (patch 0015)
>       - Reorder code to be more sensible (patch 0016)
>       - Drop SO_PEERCONTEXT as it's not needed yet (patch 0023)

Looks like you also dropped "LSM: Use lsmcontext in 
security_dentry_init_security" entirely (was patch 16 in v13).

Re: [PATCH v14 00/23] LSM: Module stacking for AppArmor

[Stephen Smalley]

On 1/23/20 7:22 PM, Casey Schaufler wrote:
> This patchset provides the changes required for
> the AppArmor security module to stack safely with any other.
> 
> v14: Rebase to 5.5-rc5
>       Incorporate feedback from v13
>       - Use an array of audit rules (patch 0002)
>       - Significant change, removed Acks (patch 0002)
>       - Remove unneeded include (patch 0013)
>       - Use context.len correctly (patch 0015)
>       - Reorder code to be more sensible (patch 0016)
>       - Drop SO_PEERCONTEXT as it's not needed yet (patch 0023)

I don't know for sure if this is your bug, but it happens every time I 
boot with your patches applied and not at all on stock v5.5-rc5 so here 
it is.  Will try to bisect as time permits but not until next week. 
Trigger seems to be loading the tun driver.

[   67.726834] tun: Universal TUN/TAP device driver, 1.6
[   67.736657] 
==================================================================
[   67.741335] BUG: KASAN: slab-out-of-bounds in sock_init_data+0x14a/0x5a0
[   67.745037] Read of size 4 at addr ffff88870afe8928 by task libvirtd/1238

[   67.751861] CPU: 4 PID: 1238 Comm: libvirtd Tainted: G 
T 5.5.0-rc5+ #54
[   67.756250] Call Trace:
[   67.759510]  dump_stack+0xb8/0x110
[   67.761604]  print_address_description.constprop.0+0x1f/0x280
[   67.763768]  __kasan_report.cold+0x75/0x8f
[   67.765895]  ? sock_init_data+0x14a/0x5a0
[   67.768282]  kasan_report+0xe/0x20
[   67.770397]  sock_init_data+0x14a/0x5a0
[   67.772511]  tun_chr_open+0x1de/0x280 [tun]
[   67.774644]  misc_open+0x1cb/0x210
[   67.776820]  chrdev_open+0x15b/0x350
[   67.778917]  ? cdev_put.part.0+0x30/0x30
[   67.781030]  do_dentry_open+0x2cb/0x800
[   67.783135]  ? cdev_put.part.0+0x30/0x30
[   67.785225]  ? devcgroup_check_permission+0x11a/0x260
[   67.787321]  ? __x64_sys_fchdir+0xf0/0xf0
[   67.789418]  ? security_inode_permission+0x5b/0x70
[   67.791513]  path_openat+0x858/0x14a0
[   67.793589]  ? path_mountpoint+0x5e0/0x5e0
[   67.795719]  ? mark_lock+0xb8/0xb00
[   67.797786]  do_filp_open+0x11e/0x1b0
[   67.799840]  ? may_open_dev+0x60/0x60
[   67.801871]  ? match_held_lock+0x1b/0x240
[   67.803968]  ? lock_downgrade+0x360/0x360
[   67.805997]  ? do_raw_spin_lock+0x119/0x1d0
[   67.808041]  ? rwlock_bug.part.0+0x60/0x60
[   67.810099]  ? do_raw_spin_unlock+0xa3/0x130
[   67.812244]  ? _raw_spin_unlock+0x1f/0x30
[   67.814287]  ? __alloc_fd+0x143/0x2f0
[   67.816324]  do_sys_open+0x1f0/0x2d0
[   67.818358]  ? filp_open+0x50/0x50
[   67.820404]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[   67.822447]  ? lockdep_hardirqs_off+0xbe/0x100
[   67.824473]  ? mark_held_locks+0x24/0x90
[   67.826484]  do_syscall_64+0x74/0xd0
[   67.828480]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   67.830478] RIP: 0033:0x7f1a2cce6074
[   67.832495] Code: 24 20 eb 8f 66 90 44 89 54 24 0c e8 86 f4 ff ff 44 
8b 54 24 0c 44 89 e2 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 
05 <48> 3d 00 f0 ff ff 77 32 44 89 c7 89 44 24 0c e8 b8 f4 ff ff 8b 44
[   67.834760] RSP: 002b:00007f19e4af46d0 EFLAGS: 00000293 ORIG_RAX: 
0000000000000101
[   67.837032] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 
00007f1a2cce6074
[   67.839318] RDX: 0000000000000002 RSI: 00007f1a2d0bfb67 RDI: 
00000000ffffff9c
[   67.841598] RBP: 00007f1a2d0bfb67 R08: 0000000000000000 R09: 
00007f19e4af4914
[   67.843941] R10: 0000000000000000 R11: 0000000000000293 R12: 
0000000000000002
[   67.846283] R13: 000000000000000d R14: 00007f19e4af4920 R15: 
00007f1a2d0bfb67

[   67.850936] Allocated by task 1238:
[   67.853241]  save_stack+0x1b/0x80
[   67.855533]  __kasan_kmalloc.constprop.0+0xc2/0xd0
[   67.857935]  sk_prot_alloc+0x115/0x170
[   67.860235]  sk_alloc+0x2f/0xa10
[   67.862541]  tun_chr_open+0x4d/0x280 [tun]
[   67.864894]  misc_open+0x1cb/0x210
[   67.867164]  chrdev_open+0x15b/0x350
[   67.869448]  do_dentry_open+0x2cb/0x800
[   67.871768]  path_openat+0x858/0x14a0
[   67.874041]  do_filp_open+0x11e/0x1b0
[   67.876328]  do_sys_open+0x1f0/0x2d0
[   67.878592]  do_syscall_64+0x74/0xd0
[   67.880899]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

[   67.885431] Freed by task 726:
[   67.887689]  save_stack+0x1b/0x80
[   67.889967]  __kasan_slab_free+0x12c/0x170
[   67.892197]  kfree+0xff/0x430
[   67.894444]  uevent_show+0x176/0x1b0
[   67.896709]  dev_attr_show+0x37/0x70
[   67.898940]  sysfs_kf_seq_show+0x119/0x210
[   67.901159]  seq_read+0x29d/0x720
[   67.903367]  vfs_read+0xf9/0x1f0
[   67.905538]  ksys_read+0xc9/0x160
[   67.907736]  do_syscall_64+0x74/0xd0
[   67.909889]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

[   67.914100] The buggy address belongs to the object at ffff88870afe8000
                 which belongs to the cache kmalloc-4k of size 4096
[   67.918357] The buggy address is located 2344 bytes inside of
                 4096-byte region [ffff88870afe8000, ffff88870afe9000)
[   67.922562] The buggy address belongs to the page:
[   67.924725] page:ffffea001c2bfa00 refcount:1 mapcount:0 
mapping:ffff88881f00de00 index:0x0 compound_mapcount: 0
[   67.926926] raw: 0017ffe000010200 ffffea001c167a00 0000000200000002 
ffff88881f00de00
[   67.929144] raw: 0000000000000000 0000000080040004 00000001ffffffff 
0000000000000000
[   67.931362] page dumped because: kasan: bad access detected

[   67.936192] Memory state around the buggy address:
[   67.938438]  ffff88870afe8800: 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00
[   67.941078]  ffff88870afe8880: fc fc fc fc fc fc fc fc fc fc fc fc fc 
fc fc fc
[   67.943393] >ffff88870afe8900: fc fc fc fc fc fc fc fc fc fc fc fc fc 
fc fc fc
[   67.945709]                                   ^
[   67.948000]  ffff88870afe8980: fc fc fc fc fc fc fc fc fc fc fc fc fc 
fc fc fc
[   67.950311]  ffff88870afe8a00: fc fc fc fc fc fc fc fc fc fc fc fc fc 
fc fc fc
[   67.952629] 
==================================================================

Re: [PATCH v14 00/23] LSM: Module stacking for AppArmor

[Casey Schaufler]

On 1/24/2020 1:04 PM, Stephen Smalley wrote:
> On 1/23/20 7:22 PM, Casey Schaufler wrote:
>> This patchset provides the changes required for
>> the AppArmor security module to stack safely with any other.
>>
>> v14: Rebase to 5.5-rc5
>>       Incorporate feedback from v13
>>       - Use an array of audit rules (patch 0002)
>>       - Significant change, removed Acks (patch 0002)
>>       - Remove unneeded include (patch 0013)
>>       - Use context.len correctly (patch 0015)
>>       - Reorder code to be more sensible (patch 0016)
>>       - Drop SO_PEERCONTEXT as it's not needed yet (patch 0023)
>
> I don't know for sure if this is your bug, but it happens every time I boot with your patches applied and not at all on stock v5.5-rc5 so here it is.  Will try to bisect as time permits but not until next week. Trigger seems to be loading the tun driver.

Thanks. I will have a look as well.

>
> [   67.726834] tun: Universal TUN/TAP device driver, 1.6
> [   67.736657] ==================================================================
> [   67.741335] BUG: KASAN: slab-out-of-bounds in sock_init_data+0x14a/0x5a0
> [   67.745037] Read of size 4 at addr ffff88870afe8928 by task libvirtd/1238
>
> [   67.751861] CPU: 4 PID: 1238 Comm: libvirtd Tainted: G T 5.5.0-rc5+ #54
> [   67.756250] Call Trace:
> [   67.759510]  dump_stack+0xb8/0x110
> [   67.761604]  print_address_description.constprop.0+0x1f/0x280
> [   67.763768]  __kasan_report.cold+0x75/0x8f
> [   67.765895]  ? sock_init_data+0x14a/0x5a0
> [   67.768282]  kasan_report+0xe/0x20
> [   67.770397]  sock_init_data+0x14a/0x5a0
> [   67.772511]  tun_chr_open+0x1de/0x280 [tun]
> [   67.774644]  misc_open+0x1cb/0x210
> [   67.776820]  chrdev_open+0x15b/0x350
> [   67.778917]  ? cdev_put.part.0+0x30/0x30
> [   67.781030]  do_dentry_open+0x2cb/0x800
> [   67.783135]  ? cdev_put.part.0+0x30/0x30
> [   67.785225]  ? devcgroup_check_permission+0x11a/0x260
> [   67.787321]  ? __x64_sys_fchdir+0xf0/0xf0
> [   67.789418]  ? security_inode_permission+0x5b/0x70
> [   67.791513]  path_openat+0x858/0x14a0
> [   67.793589]  ? path_mountpoint+0x5e0/0x5e0
> [   67.795719]  ? mark_lock+0xb8/0xb00
> [   67.797786]  do_filp_open+0x11e/0x1b0
> [   67.799840]  ? may_open_dev+0x60/0x60
> [   67.801871]  ? match_held_lock+0x1b/0x240
> [   67.803968]  ? lock_downgrade+0x360/0x360
> [   67.805997]  ? do_raw_spin_lock+0x119/0x1d0
> [   67.808041]  ? rwlock_bug.part.0+0x60/0x60
> [   67.810099]  ? do_raw_spin_unlock+0xa3/0x130
> [   67.812244]  ? _raw_spin_unlock+0x1f/0x30
> [   67.814287]  ? __alloc_fd+0x143/0x2f0
> [   67.816324]  do_sys_open+0x1f0/0x2d0
> [   67.818358]  ? filp_open+0x50/0x50
> [   67.820404]  ? trace_hardirqs_on_thunk+0x1a/0x1c
> [   67.822447]  ? lockdep_hardirqs_off+0xbe/0x100
> [   67.824473]  ? mark_held_locks+0x24/0x90
> [   67.826484]  do_syscall_64+0x74/0xd0
> [   67.828480]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
> [   67.830478] RIP: 0033:0x7f1a2cce6074
> [   67.832495] Code: 24 20 eb 8f 66 90 44 89 54 24 0c e8 86 f4 ff ff 44 8b 54 24 0c 44 89 e2 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 32 44 89 c7 89 44 24 0c e8 b8 f4 ff ff 8b 44
> [   67.834760] RSP: 002b:00007f19e4af46d0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
> [   67.837032] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1a2cce6074
> [   67.839318] RDX: 0000000000000002 RSI: 00007f1a2d0bfb67 RDI: 00000000ffffff9c
> [   67.841598] RBP: 00007f1a2d0bfb67 R08: 0000000000000000 R09: 00007f19e4af4914
> [   67.843941] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002
> [   67.846283] R13: 000000000000000d R14: 00007f19e4af4920 R15: 00007f1a2d0bfb67
>
> [   67.850936] Allocated by task 1238:
> [   67.853241]  save_stack+0x1b/0x80
> [   67.855533]  __kasan_kmalloc.constprop.0+0xc2/0xd0
> [   67.857935]  sk_prot_alloc+0x115/0x170
> [   67.860235]  sk_alloc+0x2f/0xa10
> [   67.862541]  tun_chr_open+0x4d/0x280 [tun]
> [   67.864894]  misc_open+0x1cb/0x210
> [   67.867164]  chrdev_open+0x15b/0x350
> [   67.869448]  do_dentry_open+0x2cb/0x800
> [   67.871768]  path_openat+0x858/0x14a0
> [   67.874041]  do_filp_open+0x11e/0x1b0
> [   67.876328]  do_sys_open+0x1f0/0x2d0
> [   67.878592]  do_syscall_64+0x74/0xd0
> [   67.880899]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> [   67.885431] Freed by task 726:
> [   67.887689]  save_stack+0x1b/0x80
> [   67.889967]  __kasan_slab_free+0x12c/0x170
> [   67.892197]  kfree+0xff/0x430
> [   67.894444]  uevent_show+0x176/0x1b0
> [   67.896709]  dev_attr_show+0x37/0x70
> [   67.898940]  sysfs_kf_seq_show+0x119/0x210
> [   67.901159]  seq_read+0x29d/0x720
> [   67.903367]  vfs_read+0xf9/0x1f0
> [   67.905538]  ksys_read+0xc9/0x160
> [   67.907736]  do_syscall_64+0x74/0xd0
> [   67.909889]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> [   67.914100] The buggy address belongs to the object at ffff88870afe8000
>                 which belongs to the cache kmalloc-4k of size 4096
> [   67.918357] The buggy address is located 2344 bytes inside of
>                 4096-byte region [ffff88870afe8000, ffff88870afe9000)
> [   67.922562] The buggy address belongs to the page:
> [   67.924725] page:ffffea001c2bfa00 refcount:1 mapcount:0 mapping:ffff88881f00de00 index:0x0 compound_mapcount: 0
> [   67.926926] raw: 0017ffe000010200 ffffea001c167a00 0000000200000002 ffff88881f00de00
> [   67.929144] raw: 0000000000000000 0000000080040004 00000001ffffffff 0000000000000000
> [   67.931362] page dumped because: kasan: bad access detected
>
> [   67.936192] Memory state around the buggy address:
> [   67.938438]  ffff88870afe8800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> [   67.941078]  ffff88870afe8880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> [   67.943393] >ffff88870afe8900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> [   67.945709]                                   ^
> [   67.948000]  ffff88870afe8980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> [   67.950311]  ffff88870afe8a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> [   67.952629] ==================================================================

Re: [PATCH v14 00/23] LSM: Module stacking for AppArmor

[Stephen Smalley]

On 1/24/20 4:49 PM, Casey Schaufler wrote:
> On 1/24/2020 1:04 PM, Stephen Smalley wrote:
>> On 1/23/20 7:22 PM, Casey Schaufler wrote:
>>> This patchset provides the changes required for
>>> the AppArmor security module to stack safely with any other.
>>>
>>> v14: Rebase to 5.5-rc5
>>>        Incorporate feedback from v13
>>>        - Use an array of audit rules (patch 0002)
>>>        - Significant change, removed Acks (patch 0002)
>>>        - Remove unneeded include (patch 0013)
>>>        - Use context.len correctly (patch 0015)
>>>        - Reorder code to be more sensible (patch 0016)
>>>        - Drop SO_PEERCONTEXT as it's not needed yet (patch 0023)
>>
>> I don't know for sure if this is your bug, but it happens every time I boot with your patches applied and not at all on stock v5.5-rc5 so here it is.  Will try to bisect as time permits but not until next week. Trigger seems to be loading the tun driver.
> 
> Thanks. I will have a look as well.

Bisection led to the first patch in the series, "LSM: Infrastructure 
management of the sock security". Still not sure if the bug is in the 
patch itself or just being surfaced by it.

>>
>> [   67.726834] tun: Universal TUN/TAP device driver, 1.6
>> [   67.736657] ==================================================================
>> [   67.741335] BUG: KASAN: slab-out-of-bounds in sock_init_data+0x14a/0x5a0
>> [   67.745037] Read of size 4 at addr ffff88870afe8928 by task libvirtd/1238
>>
>> [   67.751861] CPU: 4 PID: 1238 Comm: libvirtd Tainted: G T 5.5.0-rc5+ #54
>> [   67.756250] Call Trace:
>> [   67.759510]  dump_stack+0xb8/0x110
>> [   67.761604]  print_address_description.constprop.0+0x1f/0x280
>> [   67.763768]  __kasan_report.cold+0x75/0x8f
>> [   67.765895]  ? sock_init_data+0x14a/0x5a0
>> [   67.768282]  kasan_report+0xe/0x20
>> [   67.770397]  sock_init_data+0x14a/0x5a0
>> [   67.772511]  tun_chr_open+0x1de/0x280 [tun]
>> [   67.774644]  misc_open+0x1cb/0x210
>> [   67.776820]  chrdev_open+0x15b/0x350
>> [   67.778917]  ? cdev_put.part.0+0x30/0x30
>> [   67.781030]  do_dentry_open+0x2cb/0x800
>> [   67.783135]  ? cdev_put.part.0+0x30/0x30
>> [   67.785225]  ? devcgroup_check_permission+0x11a/0x260
>> [   67.787321]  ? __x64_sys_fchdir+0xf0/0xf0
>> [   67.789418]  ? security_inode_permission+0x5b/0x70
>> [   67.791513]  path_openat+0x858/0x14a0
>> [   67.793589]  ? path_mountpoint+0x5e0/0x5e0
>> [   67.795719]  ? mark_lock+0xb8/0xb00
>> [   67.797786]  do_filp_open+0x11e/0x1b0
>> [   67.799840]  ? may_open_dev+0x60/0x60
>> [   67.801871]  ? match_held_lock+0x1b/0x240
>> [   67.803968]  ? lock_downgrade+0x360/0x360
>> [   67.805997]  ? do_raw_spin_lock+0x119/0x1d0
>> [   67.808041]  ? rwlock_bug.part.0+0x60/0x60
>> [   67.810099]  ? do_raw_spin_unlock+0xa3/0x130
>> [   67.812244]  ? _raw_spin_unlock+0x1f/0x30
>> [   67.814287]  ? __alloc_fd+0x143/0x2f0
>> [   67.816324]  do_sys_open+0x1f0/0x2d0
>> [   67.818358]  ? filp_open+0x50/0x50
>> [   67.820404]  ? trace_hardirqs_on_thunk+0x1a/0x1c
>> [   67.822447]  ? lockdep_hardirqs_off+0xbe/0x100
>> [   67.824473]  ? mark_held_locks+0x24/0x90
>> [   67.826484]  do_syscall_64+0x74/0xd0
>> [   67.828480]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
>> [   67.830478] RIP: 0033:0x7f1a2cce6074
>> [   67.832495] Code: 24 20 eb 8f 66 90 44 89 54 24 0c e8 86 f4 ff ff 44 8b 54 24 0c 44 89 e2 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 32 44 89 c7 89 44 24 0c e8 b8 f4 ff ff 8b 44
>> [   67.834760] RSP: 002b:00007f19e4af46d0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
>> [   67.837032] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1a2cce6074
>> [   67.839318] RDX: 0000000000000002 RSI: 00007f1a2d0bfb67 RDI: 00000000ffffff9c
>> [   67.841598] RBP: 00007f1a2d0bfb67 R08: 0000000000000000 R09: 00007f19e4af4914
>> [   67.843941] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002
>> [   67.846283] R13: 000000000000000d R14: 00007f19e4af4920 R15: 00007f1a2d0bfb67
>>
>> [   67.850936] Allocated by task 1238:
>> [   67.853241]  save_stack+0x1b/0x80
>> [   67.855533]  __kasan_kmalloc.constprop.0+0xc2/0xd0
>> [   67.857935]  sk_prot_alloc+0x115/0x170
>> [   67.860235]  sk_alloc+0x2f/0xa10
>> [   67.862541]  tun_chr_open+0x4d/0x280 [tun]
>> [   67.864894]  misc_open+0x1cb/0x210
>> [   67.867164]  chrdev_open+0x15b/0x350
>> [   67.869448]  do_dentry_open+0x2cb/0x800
>> [   67.871768]  path_openat+0x858/0x14a0
>> [   67.874041]  do_filp_open+0x11e/0x1b0
>> [   67.876328]  do_sys_open+0x1f0/0x2d0
>> [   67.878592]  do_syscall_64+0x74/0xd0
>> [   67.880899]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
>>
>> [   67.885431] Freed by task 726:
>> [   67.887689]  save_stack+0x1b/0x80
>> [   67.889967]  __kasan_slab_free+0x12c/0x170
>> [   67.892197]  kfree+0xff/0x430
>> [   67.894444]  uevent_show+0x176/0x1b0
>> [   67.896709]  dev_attr_show+0x37/0x70
>> [   67.898940]  sysfs_kf_seq_show+0x119/0x210
>> [   67.901159]  seq_read+0x29d/0x720
>> [   67.903367]  vfs_read+0xf9/0x1f0
>> [   67.905538]  ksys_read+0xc9/0x160
>> [   67.907736]  do_syscall_64+0x74/0xd0
>> [   67.909889]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
>>
>> [   67.914100] The buggy address belongs to the object at ffff88870afe8000
>>                  which belongs to the cache kmalloc-4k of size 4096
>> [   67.918357] The buggy address is located 2344 bytes inside of
>>                  4096-byte region [ffff88870afe8000, ffff88870afe9000)
>> [   67.922562] The buggy address belongs to the page:
>> [   67.924725] page:ffffea001c2bfa00 refcount:1 mapcount:0 mapping:ffff88881f00de00 index:0x0 compound_mapcount: 0
>> [   67.926926] raw: 0017ffe000010200 ffffea001c167a00 0000000200000002 ffff88881f00de00
>> [   67.929144] raw: 0000000000000000 0000000080040004 00000001ffffffff 0000000000000000
>> [   67.931362] page dumped because: kasan: bad access detected
>>
>> [   67.936192] Memory state around the buggy address:
>> [   67.938438]  ffff88870afe8800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>> [   67.941078]  ffff88870afe8880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>> [   67.943393] >ffff88870afe8900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>> [   67.945709]                                   ^
>> [   67.948000]  ffff88870afe8980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>> [   67.950311]  ffff88870afe8a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>> [   67.952629] ==================================================================

KASAN slab-out-of-bounds in tun_chr_open/sock_init_data (Was: Re: [PATCH v14 00/23] LSM: Module stacking for AppArmor)

[Stephen Smalley]

On 1/27/20 11:14 AM, Stephen Smalley wrote:
> On 1/24/20 4:49 PM, Casey Schaufler wrote:
>> On 1/24/2020 1:04 PM, Stephen Smalley wrote:
>>> On 1/23/20 7:22 PM, Casey Schaufler wrote:
>>>> This patchset provides the changes required for
>>>> the AppArmor security module to stack safely with any other.
>>>>
>>>> v14: Rebase to 5.5-rc5
>>>>        Incorporate feedback from v13
>>>>        - Use an array of audit rules (patch 0002)
>>>>        - Significant change, removed Acks (patch 0002)
>>>>        - Remove unneeded include (patch 0013)
>>>>        - Use context.len correctly (patch 0015)
>>>>        - Reorder code to be more sensible (patch 0016)
>>>>        - Drop SO_PEERCONTEXT as it's not needed yet (patch 0023)
>>>
>>> I don't know for sure if this is your bug, but it happens every time 
>>> I boot with your patches applied and not at all on stock v5.5-rc5 so 
>>> here it is.  Will try to bisect as time permits but not until next 
>>> week. Trigger seems to be loading the tun driver.
>>
>> Thanks. I will have a look as well.
> 
> Bisection led to the first patch in the series, "LSM: Infrastructure 
> management of the sock security". Still not sure if the bug is in the 
> patch itself or just being surfaced by it.

Looks like the bug is pre-existing to me and just exposed by your patch. 
tun_chr_open() is creating a struct tun_file via sk_alloc() with its own 
tun_proto with a custom .obj_size.  It then passes the tun_file->socket 
and ->sk fields to sock_init_data().  sock_init_data() assumes it can 
safely use SOCK_INODE(sock) if sock is non-NULL, which means that it 
presumes all such sockets were wrapped in a struct socket_alloc.  But 
this one wasn't.  I don't know if that's a bug in the tun driver for not 
wrapping its socket in a socket_alloc or in sock_init_data() for 
assuming that all sockets it is passed have been so wrapped.  KASAN is 
tripping on this assignment in sock_init_data():

net/core/sock.c:
    2871                 sk->sk_uid      =       SOCK_INODE(sock)->i_uid;

This appears to have been broken since commit 
86741ec25462e4c8cdce6df2f41ead05568c7d5e ("net: core: Add a UID field to 
struct sock.").

Previously reported here by someone else with RFC patches:
https://lore.kernel.org/netdev/20190929110502.2284-1-amade@asmblr.net/

> 
>>>
>>> [   67.726834] tun: Universal TUN/TAP device driver, 1.6
>>> [   67.736657] 
>>> ==================================================================
>>> [   67.741335] BUG: KASAN: slab-out-of-bounds in 
>>> sock_init_data+0x14a/0x5a0
>>> [   67.745037] Read of size 4 at addr ffff88870afe8928 by task 
>>> libvirtd/1238
>>>
>>> [   67.751861] CPU: 4 PID: 1238 Comm: libvirtd Tainted: G T 
>>> 5.5.0-rc5+ #54
>>> [   67.756250] Call Trace:
>>> [   67.759510]  dump_stack+0xb8/0x110
>>> [   67.761604]  print_address_description.constprop.0+0x1f/0x280
>>> [   67.763768]  __kasan_report.cold+0x75/0x8f
>>> [   67.765895]  ? sock_init_data+0x14a/0x5a0
>>> [   67.768282]  kasan_report+0xe/0x20
>>> [   67.770397]  sock_init_data+0x14a/0x5a0
>>> [   67.772511]  tun_chr_open+0x1de/0x280 [tun]
>>> [   67.774644]  misc_open+0x1cb/0x210
>>> [   67.776820]  chrdev_open+0x15b/0x350
>>> [   67.778917]  ? cdev_put.part.0+0x30/0x30
>>> [   67.781030]  do_dentry_open+0x2cb/0x800
>>> [   67.783135]  ? cdev_put.part.0+0x30/0x30
>>> [   67.785225]  ? devcgroup_check_permission+0x11a/0x260
>>> [   67.787321]  ? __x64_sys_fchdir+0xf0/0xf0
>>> [   67.789418]  ? security_inode_permission+0x5b/0x70
>>> [   67.791513]  path_openat+0x858/0x14a0
>>> [   67.793589]  ? path_mountpoint+0x5e0/0x5e0
>>> [   67.795719]  ? mark_lock+0xb8/0xb00
>>> [   67.797786]  do_filp_open+0x11e/0x1b0
>>> [   67.799840]  ? may_open_dev+0x60/0x60
>>> [   67.801871]  ? match_held_lock+0x1b/0x240
>>> [   67.803968]  ? lock_downgrade+0x360/0x360
>>> [   67.805997]  ? do_raw_spin_lock+0x119/0x1d0
>>> [   67.808041]  ? rwlock_bug.part.0+0x60/0x60
>>> [   67.810099]  ? do_raw_spin_unlock+0xa3/0x130
>>> [   67.812244]  ? _raw_spin_unlock+0x1f/0x30
>>> [   67.814287]  ? __alloc_fd+0x143/0x2f0
>>> [   67.816324]  do_sys_open+0x1f0/0x2d0
>>> [   67.818358]  ? filp_open+0x50/0x50
>>> [   67.820404]  ? trace_hardirqs_on_thunk+0x1a/0x1c
>>> [   67.822447]  ? lockdep_hardirqs_off+0xbe/0x100
>>> [   67.824473]  ? mark_held_locks+0x24/0x90
>>> [   67.826484]  do_syscall_64+0x74/0xd0
>>> [   67.828480]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
>>> [   67.830478] RIP: 0033:0x7f1a2cce6074
>>> [   67.832495] Code: 24 20 eb 8f 66 90 44 89 54 24 0c e8 86 f4 ff ff 
>>> 44 8b 54 24 0c 44 89 e2 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 
>>> 00 0f 05 <48> 3d 00 f0 ff ff 77 32 44 89 c7 89 44 24 0c e8 b8 f4 ff 
>>> ff 8b 44
>>> [   67.834760] RSP: 002b:00007f19e4af46d0 EFLAGS: 00000293 ORIG_RAX: 
>>> 0000000000000101
>>> [   67.837032] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 
>>> 00007f1a2cce6074
>>> [   67.839318] RDX: 0000000000000002 RSI: 00007f1a2d0bfb67 RDI: 
>>> 00000000ffffff9c
>>> [   67.841598] RBP: 00007f1a2d0bfb67 R08: 0000000000000000 R09: 
>>> 00007f19e4af4914
>>> [   67.843941] R10: 0000000000000000 R11: 0000000000000293 R12: 
>>> 0000000000000002
>>> [   67.846283] R13: 000000000000000d R14: 00007f19e4af4920 R15: 
>>> 00007f1a2d0bfb67
>>>
>>> [   67.850936] Allocated by task 1238:
>>> [   67.853241]  save_stack+0x1b/0x80
>>> [   67.855533]  __kasan_kmalloc.constprop.0+0xc2/0xd0
>>> [   67.857935]  sk_prot_alloc+0x115/0x170
>>> [   67.860235]  sk_alloc+0x2f/0xa10
>>> [   67.862541]  tun_chr_open+0x4d/0x280 [tun]
>>> [   67.864894]  misc_open+0x1cb/0x210
>>> [   67.867164]  chrdev_open+0x15b/0x350
>>> [   67.869448]  do_dentry_open+0x2cb/0x800
>>> [   67.871768]  path_openat+0x858/0x14a0
>>> [   67.874041]  do_filp_open+0x11e/0x1b0
>>> [   67.876328]  do_sys_open+0x1f0/0x2d0
>>> [   67.878592]  do_syscall_64+0x74/0xd0
>>> [   67.880899]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
>>>
>>> [   67.885431] Freed by task 726:
>>> [   67.887689]  save_stack+0x1b/0x80
>>> [   67.889967]  __kasan_slab_free+0x12c/0x170
>>> [   67.892197]  kfree+0xff/0x430
>>> [   67.894444]  uevent_show+0x176/0x1b0
>>> [   67.896709]  dev_attr_show+0x37/0x70
>>> [   67.898940]  sysfs_kf_seq_show+0x119/0x210
>>> [   67.901159]  seq_read+0x29d/0x720
>>> [   67.903367]  vfs_read+0xf9/0x1f0
>>> [   67.905538]  ksys_read+0xc9/0x160
>>> [   67.907736]  do_syscall_64+0x74/0xd0
>>> [   67.909889]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
>>>
>>> [   67.914100] The buggy address belongs to the object at 
>>> ffff88870afe8000
>>>                  which belongs to the cache kmalloc-4k of size 4096
>>> [   67.918357] The buggy address is located 2344 bytes inside of
>>>                  4096-byte region [ffff88870afe8000, ffff88870afe9000)
>>> [   67.922562] The buggy address belongs to the page:
>>> [   67.924725] page:ffffea001c2bfa00 refcount:1 mapcount:0 
>>> mapping:ffff88881f00de00 index:0x0 compound_mapcount: 0
>>> [   67.926926] raw: 0017ffe000010200 ffffea001c167a00 
>>> 0000000200000002 ffff88881f00de00
>>> [   67.929144] raw: 0000000000000000 0000000080040004 
>>> 00000001ffffffff 0000000000000000
>>> [   67.931362] page dumped because: kasan: bad access detected
>>>
>>> [   67.936192] Memory state around the buggy address:
>>> [   67.938438]  ffff88870afe8800: 00 00 00 00 00 00 00 00 00 00 00 00 
>>> 00 00 00 00
>>> [   67.941078]  ffff88870afe8880: fc fc fc fc fc fc fc fc fc fc fc fc 
>>> fc fc fc fc
>>> [   67.943393] >ffff88870afe8900: fc fc fc fc fc fc fc fc fc fc fc fc 
>>> fc fc fc fc
>>> [   67.945709]                                   ^
>>> [   67.948000]  ffff88870afe8980: fc fc fc fc fc fc fc fc fc fc fc fc 
>>> fc fc fc fc
>>> [   67.950311]  ffff88870afe8a00: fc fc fc fc fc fc fc fc fc fc fc fc 
>>> fc fc fc fc
>>> [   67.952629] 
>>> ==================================================================
> 

Re: KASAN slab-out-of-bounds in tun_chr_open/sock_init_data (Was: Re: [PATCH v14 00/23] LSM: Module stacking for AppArmor)

[Casey Schaufler]

On 1/27/2020 8:56 AM, Stephen Smalley wrote:
> On 1/27/20 11:14 AM, Stephen Smalley wrote:
>> On 1/24/20 4:49 PM, Casey Schaufler wrote:
>>> On 1/24/2020 1:04 PM, Stephen Smalley wrote:
>>>> On 1/23/20 7:22 PM, Casey Schaufler wrote:
>>>>> This patchset provides the changes required for
>>>>> the AppArmor security module to stack safely with any other.
>>>>>
>>>>> v14: Rebase to 5.5-rc5
>>>>>        Incorporate feedback from v13
>>>>>        - Use an array of audit rules (patch 0002)
>>>>>        - Significant change, removed Acks (patch 0002)
>>>>>        - Remove unneeded include (patch 0013)
>>>>>        - Use context.len correctly (patch 0015)
>>>>>        - Reorder code to be more sensible (patch 0016)
>>>>>        - Drop SO_PEERCONTEXT as it's not needed yet (patch 0023)
>>>>
>>>> I don't know for sure if this is your bug, but it happens every time I boot with your patches applied and not at all on stock v5.5-rc5 so here it is.  Will try to bisect as time permits but not until next week. Trigger seems to be loading the tun driver.
>>>
>>> Thanks. I will have a look as well.
>>
>> Bisection led to the first patch in the series, "LSM: Infrastructure management of the sock security". Still not sure if the bug is in the patch itself or just being surfaced by it.
>
> Looks like the bug is pre-existing to me and just exposed by your patch.

OK, thanks. I don't see how moving the allocation ought to have
perturbed that, but it's good to know what happened. 

BUG: sock_init_data() assumes socket is embedded in socket_alloc, tun/tap does not

[Stephen Smalley]

Since commit 86741ec25462e4c8cdce6df2f41ead05568c7d5e ("net: core: Add a 
UID field to struct sock.") circa v4.10, sock_init_data() dereferences 
SOCK_INODE(sock) whenever sock is non-NULL, thereby requiring all 
callers that provide a socket to have embedded it within a struct 
socket_alloc.  However, the tun and tap drivers embed a struct socket 
within their own data structures (tun_file and tap_queue), call 
sock_init_data() on these sockets, and were not updated to wrap these 
sockets within socket_alloc. I haven't checked whether there may be 
other cases beyond tun/tap.  A bug report with RFC patches was posted by 
amade@asmblr.net back in September to address the tun/tap case here:
https://lore.kernel.org/netdev/20190929110502.2284-1-amade@asmblr.net/ 
seemingly without any response or follow-up that I could see in the 
archives.

Is sock_init_data() wrong to make this assumption, and if so, how should 
it be fixed?  Or should tun/tap and any other callers be updated to 
embed their sockets within socket_alloc structures?  Or should they not 
call sock_init_data() on their sockets?

Sorry if this has been discussed elsewhere but I couldn't find anything 
beyond what I cited above.

Re: [PATCH v14 00/23] LSM: Module stacking for AppArmor

[Casey Schaufler]

On 1/27/2020 8:14 AM, Stephen Smalley wrote:
> On 1/24/20 4:49 PM, Casey Schaufler wrote:
>> On 1/24/2020 1:04 PM, Stephen Smalley wrote:
>>> On 1/23/20 7:22 PM, Casey Schaufler wrote:
>>>> This patchset provides the changes required for
>>>> the AppArmor security module to stack safely with any other.
>>>>
>>>> v14: Rebase to 5.5-rc5
>>>>        Incorporate feedback from v13
>>>>        - Use an array of audit rules (patch 0002)
>>>>        - Significant change, removed Acks (patch 0002)
>>>>        - Remove unneeded include (patch 0013)
>>>>        - Use context.len correctly (patch 0015)
>>>>        - Reorder code to be more sensible (patch 0016)
>>>>        - Drop SO_PEERCONTEXT as it's not needed yet (patch 0023)
>>>
>>> I don't know for sure if this is your bug, but it happens every time I boot with your patches applied and not at all on stock v5.5-rc5 so here it is.  Will try to bisect as time permits but not until next week. Trigger seems to be loading the tun driver.
>>
>> Thanks. I will have a look as well.
>
> Bisection led to the first patch in the series, "LSM: Infrastructure management of the sock security". Still not sure if the bug is in the patch itself or just being surfaced by it.

It looks like the tun code is making a private socket in tun_chr_open()
without initializing the sk_security member. It's possible that this used
to work implicitly, but I don't see how the change should have broken that.
Investigation continues.