[PATCH v22 05/23] LSM: Use lsmblob in security_secctx_to_secid

[PATCH v22 05/23] LSM: Use lsmblob in security_secctx_to_secid

[Casey Schaufler]

Change the security_secctx_to_secid interface to use a lsmblob
structure in place of the single u32 secid in support of
module stacking. Change its callers to do the same.

The security module hook is unchanged, still passing back a secid.
The infrastructure passes the correct entry from the lsmblob.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: netdev@vger.kernel.org
---
 include/linux/security.h          | 26 ++++++++++++++++++--
 kernel/cred.c                     |  4 +---
 net/netfilter/nft_meta.c          | 10 ++++----
 net/netfilter/xt_SECMARK.c        |  7 +++++-
 net/netlabel/netlabel_unlabeled.c | 23 +++++++++++-------
 security/security.c               | 40 ++++++++++++++++++++++++++-----
 6 files changed, 85 insertions(+), 25 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 948d12a5eb25..0766725a6b21 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -191,6 +191,27 @@ static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)
 	return !memcmp(bloba, blobb, sizeof(*bloba));
 }
 
+/**
+ * lsmblob_value - find the first non-zero value in an lsmblob structure.
+ * @blob: Pointer to the data
+ *
+ * This needs to be used with extreme caution, as the cases where
+ * it is appropriate are rare.
+ *
+ * Return the first secid value set in the lsmblob.
+ * There should only be one.
+ */
+static inline u32 lsmblob_value(const struct lsmblob *blob)
+{
+	int i;
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++)
+		if (blob->secid[i])
+			return blob->secid[i];
+
+	return 0;
+}
+
 /* These functions are in security/commoncap.c */
 extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
 		       int cap, unsigned int opts);
@@ -508,7 +529,8 @@ 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);
@@ -1335,7 +1357,7 @@ 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 22e0e7cbefde..848306c7d823 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -757,14 +757,12 @@ 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 b37bd02448d8..f1b9b0021414 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -811,21 +811,21 @@ 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);
+	err = security_secmark_relabel_packet(lsmblob_value(&blob));
 	if (err)
 		return err;
 
-	priv->secid = tmp_secid;
+	priv->secid = lsmblob_value(&blob);
 	return 0;
 }
 
diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
index 75625d13e976..9845d98e6b77 100644
--- a/net/netfilter/xt_SECMARK.c
+++ b/net/netfilter/xt_SECMARK.c
@@ -43,13 +43,14 @@ 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",
@@ -57,6 +58,10 @@ static int checkentry_lsm(struct xt_secmark_target_info *info)
 		return err;
 	}
 
+	/* xt_secmark_target_info can't be changed to use lsmblobs because
+	 * it is exposed as an API. Use lsmblob_value() to get the one
+	 * value that got set by security_secctx_to_secid(). */
+	info->secid = lsmblob_value(&blob);
 	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 2e8e3f7b2111..8c064342169f 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -882,7 +882,7 @@ 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
@@ -906,13 +906,18 @@ 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;
 
+	/* netlbl_unlhsh_add will be changed to pass a struct lsmblob *
+	 * instead of a u32 later in this patch set. security_secctx_to_secid()
+	 * will only be setting one entry in the lsmblob struct, so it is
+	 * safe to use lsmblob_value() to get that one value. */
+
 	return netlbl_unlhsh_add(&init_net,
-				 dev_name, addr, mask, addr_len, secid,
-				 &audit_info);
+				 dev_name, addr, mask, addr_len,
+				 lsmblob_value(&blob), &audit_info);
 }
 
 /**
@@ -933,7 +938,7 @@ 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
@@ -955,13 +960,15 @@ 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;
 
+	/* security_secctx_to_secid() will only put one secid into the lsmblob
+	 * so it's safe to use lsmblob_value() to get the secid. */
 	return netlbl_unlhsh_add(&init_net,
-				 NULL, addr, mask, addr_len, secid,
-				 &audit_info);
+				 NULL, addr, mask, addr_len,
+				 lsmblob_value(&blob), &audit_info);
 }
 
 /**
diff --git a/security/security.c b/security/security.c
index 3a88a90ddba6..eac7c10b8cfa 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2081,10 +2081,22 @@ 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);
 
@@ -2235,10 +2247,26 @@ 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,
+				     u32 *secid)
 {
-	return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock,
-			     skb, secid);
+	struct security_hook_list *hp;
+	int rc = -ENOPROTOOPT;
+
+	/*
+	 * Only one security module should provide a real hook for
+	 * this. A stub or bypass like is used in BPF should either
+	 * (somehow) leave rc unaltered or return -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, secid);
+		if (rc != -ENOPROTOOPT)
+			break;
+	}
+	return rc;
 }
 EXPORT_SYMBOL(security_socket_getpeersec_dgram);
 
-- 
2.24.1

Re: [PATCH v22 05/23] LSM: Use lsmblob in security_secctx_to_secid

[James Morris]

On Wed, 4 Nov 2020, Casey Schaufler wrote:

> Change the security_secctx_to_secid interface to use a lsmblob
> structure in place of the single u32 secid in support of
> module stacking. Change its callers to do the same.
> 
> The security module hook is unchanged, still passing back a secid.
> The infrastructure passes the correct entry from the lsmblob.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> Cc: netdev@vger.kernel.org

You probably need to include Netfilter maintainers specifically for this 
(added them + the Netfilter list).

This also needs signoffs from LSM owners.

-- 
James Morris
<jmorris@namei.org>

[PATCH v22 06/23] 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.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: netdev@vger.kernel.org
Cc: linux-audit@redhat.com
---
 drivers/android/binder.c                | 12 +++++++++-
 include/linux/security.h                |  5 +++--
 include/net/scm.h                       |  7 +++++-
 kernel/audit.c                          | 20 +++++++++++++++--
 kernel/auditsc.c                        | 28 +++++++++++++++++++----
 net/ipv4/ip_sockglue.c                  |  4 +++-
 net/netfilter/nf_conntrack_netlink.c    | 14 ++++++++++--
 net/netfilter/nf_conntrack_standalone.c |  4 +++-
 net/netfilter/nfnetlink_queue.c         | 11 +++++++--
 net/netlabel/netlabel_unlabeled.c       | 30 +++++++++++++++++++++----
 net/netlabel/netlabel_user.c            |  6 ++---
 security/security.c                     | 11 +++++----
 12 files changed, 123 insertions(+), 29 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index b5117576792b..55f3fa073c7b 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3088,10 +3088,20 @@ 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);
+		/*
+		 * Later in this patch set security_task_getsecid() will
+		 * provide a lsmblob instead of a secid. lsmblob_init
+		 * is used to ensure that all the secids in the lsmblob
+		 * get the value returned from security_task_getsecid(),
+		 * which means that the one expected by
+		 * security_secid_to_secctx() will be set.
+		 */
+		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 0766725a6b21..fad361bf320e 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -528,7 +528,7 @@ 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);
@@ -1350,7 +1350,8 @@ 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 1ce365f4c256..23a35ff1b3f2 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -92,12 +92,17 @@ 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 lsmblob lb;
 	char *secdata;
 	u32 seclen;
 	int err;
 
 	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
-		err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
+		/* There can only be one security module using the secid,
+		 * and the infrastructure will know which it is.
+		 */
+		lsmblob_init(&lb, scm->secid);
+		err = security_secid_to_secctx(&lb, &secdata, &seclen);
 
 		if (!err) {
 			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
diff --git a/kernel/audit.c b/kernel/audit.c
index 68cee3bc8cfe..4cd6339e513d 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1442,7 +1442,16 @@ 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 sets all values in the lsmblob
+			 * to audit_sig_sid. This is temporary until
+			 * audit_sig_sid is converted to a lsmblob, which
+			 * happens later in this patch set.
+			 */
+			lsmblob_init(&blob, audit_sig_sid);
+			err = security_secid_to_secctx(&blob, &ctx, &len);
 			if (err)
 				return err;
 		}
@@ -2128,12 +2137,19 @@ 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 sets all values in the lsmblob to sid.
+	 * This is temporary until security_task_getsecid is converted
+	 * to use a lsmblob, which happens later in this patch set.
+	 */
+	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 7dd6b815a9eb..5f9bdd62f78d 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -673,6 +673,13 @@ static int audit_filter_rules(struct task_struct *tsk,
 					security_task_getsecid(tsk, &sid);
 					need_sid = 0;
 				}
+				/*
+				 * lsmblob_init sets all values in the lsmblob
+				 * to sid. This is temporary until
+				 * security_task_getsecid() is converted to
+				 * provide a lsmblob, which happens later in
+				 * this patch set.
+				 */
 				lsmblob_init(&blob, sid);
 				result = security_audit_rule_match(&blob,
 								   f->type,
@@ -690,6 +697,13 @@ static int audit_filter_rules(struct task_struct *tsk,
 			if (f->lsm_isset) {
 				/* Find files that match */
 				if (name) {
+					/*
+					 * lsmblob_init sets all values in the
+					 * lsmblob to sid. This is temporary
+					 * until name->osid is converted to a
+					 * lsmblob, which happens later in
+					 * this patch set.
+					 */
 					lsmblob_init(&blob, name->osid);
 					result = security_audit_rule_match(
 								&blob,
@@ -995,6 +1009,7 @@ 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)
@@ -1004,7 +1019,8 @@ 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 {
@@ -1247,7 +1263,10 @@ 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 {
@@ -1397,9 +1416,10 @@ 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 ec6036713e2c..2f089733ada7 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 lsmblob lb;
 	char *secdata;
 	u32 seclen, secid;
 	int err;
@@ -138,7 +139,8 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 	if (err)
 		return;
 
-	err = security_secid_to_secctx(secid, &secdata, &seclen);
+	lsmblob_init(&lb, secid);
+	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 3d0fd33be018..8627ec7e13fb 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -333,8 +333,13 @@ 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() puts ct->secmark into all of the secids in blob.
+	 * security_secid_to_secctx() will know which security module
+	 * to use to create the secctx.  */
+	lsmblob_init(&blob, ct->secmark);
+	ret = security_secid_to_secctx(&blob, &secctx, &len);
 	if (ret)
 		return 0;
 
@@ -647,8 +652,13 @@ 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() puts ct->secmark into all of the secids in blob.
+	 * security_secid_to_secctx() will know which security module
+	 * to use to create the secctx.  */
+	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 46c5557c1fec..54da1a3e8cb1 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 d1d8bca03b4f..a6dbef71fc32 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -305,13 +305,20 @@ 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() puts ct->secmark into all of the secids in
+		 * blob. security_secid_to_secctx() will know which security
+		 * module to use to create the secctx.  */
+		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 8c064342169f..ba74901b89a8 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -376,6 +376,7 @@ 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))
@@ -438,7 +439,11 @@ 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() puts secid into all of the secids in blob.
+		 * security_secid_to_secctx() will know which security module
+		 * to use to create the secctx.  */
+		lsmblob_init(&blob, secid);
+		if (security_secid_to_secctx(&blob,
 					     &secctx,
 					     &secctx_len) == 0) {
 			audit_log_format(audit_buf, " sec_obj=%s", secctx);
@@ -475,6 +480,7 @@ 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,
@@ -494,8 +500,13 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 					  addr->s_addr, mask->s_addr);
 		if (dev != NULL)
 			dev_put(dev);
+		/* lsmblob_init() puts entry->secid into all of the secids
+		 * in blob. security_secid_to_secctx() will know which
+		 * security module to use to create the secctx.  */
+		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);
@@ -537,6 +548,7 @@ 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);
@@ -555,8 +567,13 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 					  addr, mask);
 		if (dev != NULL)
 			dev_put(dev);
+		/* lsmblob_init() puts entry->secid into all of the secids
+		 * in blob. security_secid_to_secctx() will know which
+		 * security module to use to create the secctx.  */
+		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);
@@ -1082,6 +1099,7 @@ 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,
@@ -1136,7 +1154,11 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
 		secid = addr6->secid;
 	}
 
-	ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
+        /* lsmblob_init() secid into all of the secids in blob.
+         * security_secid_to_secctx() will know which security module
+         * to use to create the secctx.  */
+	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 eac7c10b8cfa..ea927a00de18 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2062,17 +2062,16 @@ 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)
 {
 	struct security_hook_list *hp;
 	int rc;
 
-	/*
-	 * Currently, only one LSM can implement secid_to_secctx (i.e this
-	 * LSM hook is not "stackable").
-	 */
 	hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
-		rc = hp->hook.secid_to_secctx(secid, secdata, seclen);
+		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 != LSM_RET_DEFAULT(secid_to_secctx))
 			return rc;
 	}
-- 
2.24.1

Re: [PATCH v22 06/23] LSM: Use lsmblob in security_secid_to_secctx

[James Morris]

On Wed, 4 Nov 2020, Casey Schaufler wrote:

> Change security_secid_to_secctx() to take a lsmblob as input
> instead of a u32 secid. It will then call the LSM hooks
> using the lsmblob element allocated for that module. The
> callers have been updated as well. This allows for the
> possibility that more than one module may be called upon
> to translate a secid to a string, as can occur in the
> audit code.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> Cc: netdev@vger.kernel.org
> Cc: linux-audit@redhat.com

Ditto with this, + audit. Also, you should put primary maintainers on the 
To: line or they may miss the email.

-- 
James Morris
<jmorris@namei.org>

[PATCH v22 08/23] 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>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-integrity@vger.kernel.org
Cc: linux-audit@redhat.com
Cc: netdev@vger.kernel.org
---
 drivers/android/binder.c              | 12 +-----
 include/linux/security.h              |  7 ++--
 kernel/audit.c                        | 16 +++-----
 kernel/auditfilter.c                  |  4 +-
 kernel/auditsc.c                      | 25 ++++++------
 net/netlabel/netlabel_unlabeled.c     |  5 ++-
 net/netlabel/netlabel_user.h          |  6 ++-
 security/integrity/ima/ima_appraise.c | 10 +++--
 security/integrity/ima/ima_main.c     | 56 +++++++++++++++------------
 security/security.c                   | 12 ++++--
 10 files changed, 80 insertions(+), 73 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 55f3fa073c7b..08737a07f997 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3087,20 +3087,10 @@ 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);
-		/*
-		 * Later in this patch set security_task_getsecid() will
-		 * provide a lsmblob instead of a secid. lsmblob_init
-		 * is used to ensure that all the secids in the lsmblob
-		 * get the value returned from security_task_getsecid(),
-		 * which means that the one expected by
-		 * security_secid_to_secctx() will be set.
-		 */
-		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 be8db737da74..6b9e3571960d 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -482,7 +482,7 @@ int security_task_fix_setgid(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);
@@ -1155,9 +1155,10 @@ 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 4cd6339e513d..9e3eec0a9c29 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2136,19 +2136,12 @@ 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 sets all values in the lsmblob to sid.
-	 * This is temporary until security_task_getsecid is converted
-	 * to use a lsmblob, which happens later in this patch set.
-	 */
-	lsmblob_init(&blob, sid);
 	error = security_secid_to_secctx(&blob, &ctx, &len);
 	if (error) {
 		if (error != -EINVAL)
@@ -2356,6 +2349,7 @@ 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 ||
@@ -2366,7 +2360,9 @@ 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 e27424216159..9e73a7961665 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1330,7 +1330,6 @@ 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) {
@@ -1361,8 +1360,7 @@ 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 35d6bd0526a2..8916a13406c3 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -473,7 +473,6 @@ 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;
 
@@ -670,17 +669,9 @@ 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 sets all values in the lsmblob
-				 * to sid. This is temporary until
-				 * security_task_getsecid() is converted to
-				 * provide a lsmblob, which happens later in
-				 * this patch set.
-				 */
-				lsmblob_init(&blob, sid);
 				result = security_audit_rule_match(&blob,
 								   f->type,
 								   f->op,
@@ -2440,12 +2431,15 @@ 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);
 }
 
@@ -2461,6 +2455,7 @@ 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;
@@ -2472,7 +2467,9 @@ 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;
 	}
@@ -2493,7 +2490,9 @@ 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 ba74901b89a8..94071f67e461 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -1557,11 +1557,14 @@ 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 3dd8c2e4314e..2a18124af429 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -65,14 +65,16 @@ 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, 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,
+				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 2d1af8899cab..c9f1f6bddab5 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -388,12 +388,13 @@ 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;
@@ -419,9 +420,9 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
 	char *pathbuf = NULL;
 	const char *pathname = NULL;
 	struct inode *inode;
+	struct lsmblob blob;
 	int result = 0;
 	int action;
-	u32 secid;
 	int pcr;
 
 	/* Is mprotect making an mmap'ed file executable? */
@@ -429,9 +430,10 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
 	    !(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC))
 		return 0;
 
-	security_task_getsecid(current, &secid);
+	security_task_getsecid(current, &blob);
 	inode = file_inode(vma->vm_file);
-	action = ima_get_action(inode, current_cred(), secid, MAY_EXEC,
+	/* scaffolding */
+	action = ima_get_action(NULL, current_cred(), blob.secid[0], 0,
 				MMAP_CHECK, &pcr, &template, 0);
 
 	/* Is the mmap'ed file in policy? */
@@ -468,10 +470,12 @@ 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;
 
@@ -492,10 +496,11 @@ 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);
 }
@@ -629,7 +634,7 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
 		  bool contents)
 {
 	enum ima_hooks func;
-	u32 secid;
+	struct lsmblob blob;
 
 	/*
 	 * Do devices using pre-allocated memory run the risk of the
@@ -649,8 +654,9 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
 
 	/* Read entire file for all partial reads. */
 	func = read_idmap[read_id] ?: FILE_CHECK;
-	security_task_getsecid(current, &secid);
-	return process_measurement(file, current_cred(), secid, NULL,
+	security_task_getsecid(current, &blob);
+	/* scaffolding - until process_measurement changes */
+	return process_measurement(file, current_cred(), blob.secid[0], NULL,
 				   0, MAY_READ, func);
 }
 
@@ -679,7 +685,7 @@ 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;
 
 	/* permit signed certs */
 	if (!file && read_id == READING_X509_CERTIFICATE)
@@ -692,9 +698,10 @@ 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);
 }
 
 /**
@@ -809,7 +816,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size,
 	} hash = {};
 	int violation = 0;
 	int action = 0;
-	u32 secid;
+	struct lsmblob blob;
 
 	if (!ima_policy_flag)
 		return;
@@ -822,9 +829,10 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size,
 	 * buffer measurements.
 	 */
 	if (func) {
-		security_task_getsecid(current, &secid);
-		action = ima_get_action(inode, current_cred(), secid, 0, func,
-					&pcr, &template, keyring);
+		security_task_getsecid(current, &blob);
+		/* scaffolding */
+		action = ima_get_action(inode, current_cred(), blob.secid[0],
+					0, func, &pcr, &template, keyring);
 		if (!(action & IMA_MEASURE))
 			return;
 	}
diff --git a/security/security.c b/security/security.c
index 9c1098ecea03..421ff85015da 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1799,10 +1799,16 @@ 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 v22 13/23] 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
Cc: linux-audit@redhat.com
---
 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 08737a07f997..05266b064c38 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2838,6 +2838,7 @@ 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;
@@ -3140,7 +3141,8 @@ 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;
@@ -3473,8 +3475,10 @@ 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 197cb1234341..5dfd08357dc3 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -1273,12 +1273,16 @@ 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 9e0ca9b2b210..4b03a3e596e9 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -139,8 +139,12 @@ 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 833a2c64dfe8..4ae7e156ea87 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2717,6 +2717,7 @@ 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
@@ -3228,8 +3229,10 @@ 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 dacd64d2d141..4ed7a0790cc5 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -132,6 +132,37 @@ enum lockdown_reason {
 
 extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1];
 
+/*
+ * 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
  *
@@ -531,7 +562,7 @@ 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);
@@ -1366,7 +1397,7 @@ 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 23a35ff1b3f2..f273c4d777ec 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;
 	struct lsmblob lb;
 	char *secdata;
 	u32 seclen;
@@ -106,7 +107,9 @@ 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 1f987ac23e90..8867df3de920 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1192,6 +1192,7 @@ 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)
@@ -1449,15 +1450,18 @@ 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);
@@ -2129,6 +2133,7 @@ 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))
@@ -2142,7 +2147,8 @@ 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 b15222181700..2b06171bedeb 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -998,6 +998,7 @@ 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;
@@ -1015,7 +1016,8 @@ 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=");
@@ -1228,6 +1230,7 @@ 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;
 
@@ -1261,7 +1264,8 @@ 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) {
@@ -1407,6 +1411,7 @@ 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)) {
@@ -1415,7 +1420,8 @@ 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 2f089733ada7..a7e4c1b34b6c 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, secid;
@@ -145,7 +146,8 @@ 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 8627ec7e13fb..5d2784461798 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -334,6 +334,7 @@ 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() puts ct->secmark into all of the secids in blob.
 	 * security_secid_to_secctx() will know which security module
@@ -354,7 +355,8 @@ 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 54da1a3e8cb1..e2bdc851a477 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 a6dbef71fc32..dcc31cb7f287 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -398,6 +398,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	enum ip_conntrack_info ctinfo;
 	struct nfnl_ct_hook *nfnl_ct;
 	bool csum_verify;
+	struct lsmcontext scaff; /* scaffolding */
 	char *secdata = NULL;
 	u32 seclen = 0;
 
@@ -628,8 +629,10 @@ 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:
@@ -637,8 +640,10 @@ 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 94071f67e461..3e06efe29cfa 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -374,6 +374,7 @@ 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;
@@ -447,7 +448,9 @@ 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);
@@ -478,6 +481,7 @@ 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;
@@ -509,7 +513,9 @@ 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);
@@ -546,6 +552,7 @@ 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;
@@ -576,7 +583,8 @@ 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);
@@ -1095,6 +1103,7 @@ 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;
@@ -1165,7 +1174,9 @@ 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 f9d9f68d40cf..9107ca5a6af3 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2245,16 +2245,17 @@ 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 v22 14/23] 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.

Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: netdev@vger.kernel.org
Cc: linux-audit@redhat.com
---
 drivers/android/binder.c                | 26 +++++++---------
 include/linux/security.h                |  4 +--
 include/net/scm.h                       |  9 ++----
 kernel/audit.c                          | 39 +++++++++++-------------
 kernel/auditsc.c                        | 31 +++++++------------
 net/ipv4/ip_sockglue.c                  |  8 ++---
 net/netfilter/nf_conntrack_netlink.c    | 18 +++++------
 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, 81 insertions(+), 123 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 05266b064c38..a75ffcd0270a 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2836,9 +2836,7 @@ 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;
@@ -3092,14 +3090,14 @@ 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 */
@@ -3126,24 +3124,22 @@ 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;
@@ -3199,7 +3195,7 @@ 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)) {
@@ -3475,10 +3471,8 @@ 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 4ed7a0790cc5..c86c9870b352 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -559,7 +559,7 @@ 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);
@@ -1385,7 +1385,7 @@ 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 f273c4d777ec..b77a52f93389 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -94,8 +94,6 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
 {
 	struct lsmcontext context;
 	struct lsmblob lb;
-	char *secdata;
-	u32 seclen;
 	int err;
 
 	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
@@ -103,12 +101,11 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
 		 * and the infrastructure will know which it is.
 		 */
 		lsmblob_init(&lb, scm->secid);
-		err = security_secid_to_secctx(&lb, &secdata, &seclen);
+		err = security_secid_to_secctx(&lb, &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 8867df3de920..4e219d1c1781 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1190,9 +1190,6 @@ 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 */
 
 	err = audit_netlink_ok(skb, msg_type);
 	if (err)
@@ -1440,33 +1437,34 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		kfree(new);
 		break;
 	}
-	case AUDIT_SIGNAL_INFO:
-		len = 0;
+	case AUDIT_SIGNAL_INFO: {
+		struct lsmcontext context = { };
+		int 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);
+			len = context.len;
+			memcpy(sig_data->ctx, context.context, len);
+			security_release_secctx(&context);
 		}
 		audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
 				 sig_data, sizeof(*sig_data) + len);
 		kfree(sig_data);
 		break;
+	}
 	case AUDIT_TTY_GET: {
 		struct audit_tty_status s;
 		unsigned int t;
@@ -2129,26 +2127,23 @@ 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 2b06171bedeb..4af5861bcb9a 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -998,9 +998,7 @@ 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);
@@ -1011,13 +1009,12 @@ 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=");
@@ -1230,7 +1227,6 @@ 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;
 
@@ -1254,17 +1250,15 @@ 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);
 			}
 		}
@@ -1408,20 +1402,17 @@ 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 a7e4c1b34b6c..ae073b642fa7 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -132,8 +132,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 {
 	struct lsmcontext context;
 	struct lsmblob lb;
-	char *secdata;
-	u32 seclen, secid;
+	u32 secid;
 	int err;
 
 	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
@@ -141,12 +140,11 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 		return;
 
 	lsmblob_init(&lb, secid);
-	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 5d2784461798..e6fdcd87ab3e 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -331,8 +331,7 @@ 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;
 
@@ -340,7 +339,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 	 * security_secid_to_secctx() will know which security module
 	 * to use to create the secctx.  */
 	lsmblob_init(&blob, ct->secmark);
-	ret = security_secid_to_secctx(&blob, &secctx, &len);
+	ret = security_secid_to_secctx(&blob, &context);
 	if (ret)
 		return 0;
 
@@ -349,13 +348,12 @@ 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;
 }
@@ -655,15 +653,15 @@ 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() puts ct->secmark into all of the secids in blob.
-	 * security_secid_to_secctx() will know which security module
-	 * to use to create the secctx.  */
-	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 e2bdc851a477..c6112960fc73 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 dcc31cb7f287..84be5a49a157 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;
@@ -317,10 +318,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
 		 * blob. security_secid_to_secctx() will know which security
 		 * module to use to create the secctx.  */
 		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 3e06efe29cfa..7d426ca1aff6 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -375,8 +375,6 @@ 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) &&
@@ -444,12 +442,9 @@ int netlbl_unlhsh_add(struct net *net,
 		 * security_secid_to_secctx() will know which security module
 		 * to use to create the secctx.  */
 		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);
@@ -482,8 +477,6 @@ 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);
@@ -510,11 +503,9 @@ 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);
@@ -553,8 +544,6 @@ 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);
@@ -580,10 +569,9 @@ 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);
@@ -1106,8 +1094,6 @@ 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,
@@ -1167,15 +1153,13 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
          * security_secid_to_secctx() will know which security module
          * to use to create the secctx.  */
 	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 9107ca5a6af3..007f23797de1 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2209,18 +2209,22 @@ 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 LSM_RET_DEFAULT(secid_to_secctx);
-- 
2.24.1

[PATCH v22 16/23] 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
Cc: netfilter-devel@vger.kernel.org
---
 net/netfilter/nfnetlink_queue.c | 37 +++++++++++++--------------------
 1 file changed, 14 insertions(+), 23 deletions(-)

diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 84be5a49a157..0d8b83d84422 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -301,15 +301,13 @@ 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 void 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;
+		return;
 
 	read_lock_bh(&skb->sk->sk_callback_lock);
 
@@ -318,14 +316,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
 		 * blob. security_secid_to_secctx() will know which security
 		 * module to use to create the secctx.  */
 		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;
 #endif
-	return seclen;
+	return;
 }
 
 static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
@@ -398,12 +394,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 	struct net_device *indev;
 	struct net_device *outdev;
 	struct nf_conn *ct = NULL;
+	struct lsmcontext context = { };
 	enum ip_conntrack_info ctinfo;
 	struct nfnl_ct_hook *nfnl_ct;
 	bool csum_verify;
-	struct lsmcontext scaff; /* scaffolding */
-	char *secdata = NULL;
-	u32 seclen = 0;
 
 	size = nlmsg_total_size(sizeof(struct nfgenmsg))
 		+ nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
@@ -469,9 +463,9 @@ 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);
-		if (seclen)
-			size += nla_total_size(seclen);
+		nfqnl_get_sk_secctx(entskb, &context);
+		if (context.len)
+			size += nla_total_size(context.len);
 	}
 
 	skb = alloc_skb(size, GFP_ATOMIC);
@@ -604,7 +598,8 @@ 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 (context.len &&
+	    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)
@@ -632,10 +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 (context.len)
+		security_release_secctx(&context);
 	return skb;
 
 nla_put_failure:
@@ -643,10 +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 (context.len)
+		security_release_secctx(&context);
 	return NULL;
 }
 
-- 
2.24.1

Re: [PATCH v22 16/23] LSM: security_secid_to_secctx in netlink netfilter

[Pablo Neira Ayuso]

Hi Casey,

On Wed, Nov 04, 2020 at 04:49:17PM -0800, Casey Schaufler wrote:
> 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
> Cc: netfilter-devel@vger.kernel.org

You can carry this tag in your follow up patches.

Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>

Thanks.

> ---
>  net/netfilter/nfnetlink_queue.c | 37 +++++++++++++--------------------
>  1 file changed, 14 insertions(+), 23 deletions(-)
> 
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index 84be5a49a157..0d8b83d84422 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -301,15 +301,13 @@ 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 void 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;
> +		return;
>  
>  	read_lock_bh(&skb->sk->sk_callback_lock);
>  
> @@ -318,14 +316,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
>  		 * blob. security_secid_to_secctx() will know which security
>  		 * module to use to create the secctx.  */
>  		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;
>  #endif
> -	return seclen;
> +	return;
>  }
>  
>  static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
> @@ -398,12 +394,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
>  	struct net_device *indev;
>  	struct net_device *outdev;
>  	struct nf_conn *ct = NULL;
> +	struct lsmcontext context = { };
>  	enum ip_conntrack_info ctinfo;
>  	struct nfnl_ct_hook *nfnl_ct;
>  	bool csum_verify;
> -	struct lsmcontext scaff; /* scaffolding */
> -	char *secdata = NULL;
> -	u32 seclen = 0;
>  
>  	size = nlmsg_total_size(sizeof(struct nfgenmsg))
>  		+ nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
> @@ -469,9 +463,9 @@ 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);
> -		if (seclen)
> -			size += nla_total_size(seclen);
> +		nfqnl_get_sk_secctx(entskb, &context);
> +		if (context.len)
> +			size += nla_total_size(context.len);
>  	}
>  
>  	skb = alloc_skb(size, GFP_ATOMIC);
> @@ -604,7 +598,8 @@ 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 (context.len &&
> +	    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)
> @@ -632,10 +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 (context.len)
> +		security_release_secctx(&context);
>  	return skb;
>  
>  nla_put_failure:
> @@ -643,10 +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 (context.len)
> +		security_release_secctx(&context);
>  	return NULL;
>  }
>  
> -- 
> 2.24.1
> 

Re: [PATCH v22 16/23] LSM: security_secid_to_secctx in netlink netfilter

[James Morris]

On Tue, 10 Nov 2020, Pablo Neira Ayuso wrote:

> Hi Casey,
> 
> On Wed, Nov 04, 2020 at 04:49:17PM -0800, Casey Schaufler wrote:
> > 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
> > Cc: netfilter-devel@vger.kernel.org
> 
> You can carry this tag in your follow up patches.
> 
> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>

Thanks for the review!

> 
> Thanks.
> 
> > ---
> >  net/netfilter/nfnetlink_queue.c | 37 +++++++++++++--------------------
> >  1 file changed, 14 insertions(+), 23 deletions(-)
> > 
> > diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> > index 84be5a49a157..0d8b83d84422 100644
> > --- a/net/netfilter/nfnetlink_queue.c
> > +++ b/net/netfilter/nfnetlink_queue.c
> > @@ -301,15 +301,13 @@ 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 void 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;
> > +		return;
> >  
> >  	read_lock_bh(&skb->sk->sk_callback_lock);
> >  
> > @@ -318,14 +316,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
> >  		 * blob. security_secid_to_secctx() will know which security
> >  		 * module to use to create the secctx.  */
> >  		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;
> >  #endif
> > -	return seclen;
> > +	return;
> >  }
> >  
> >  static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
> > @@ -398,12 +394,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
> >  	struct net_device *indev;
> >  	struct net_device *outdev;
> >  	struct nf_conn *ct = NULL;
> > +	struct lsmcontext context = { };
> >  	enum ip_conntrack_info ctinfo;
> >  	struct nfnl_ct_hook *nfnl_ct;
> >  	bool csum_verify;
> > -	struct lsmcontext scaff; /* scaffolding */
> > -	char *secdata = NULL;
> > -	u32 seclen = 0;
> >  
> >  	size = nlmsg_total_size(sizeof(struct nfgenmsg))
> >  		+ nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
> > @@ -469,9 +463,9 @@ 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);
> > -		if (seclen)
> > -			size += nla_total_size(seclen);
> > +		nfqnl_get_sk_secctx(entskb, &context);
> > +		if (context.len)
> > +			size += nla_total_size(context.len);
> >  	}
> >  
> >  	skb = alloc_skb(size, GFP_ATOMIC);
> > @@ -604,7 +598,8 @@ 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 (context.len &&
> > +	    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)
> > @@ -632,10 +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 (context.len)
> > +		security_release_secctx(&context);
> >  	return skb;
> >  
> >  nla_put_failure:
> > @@ -643,10 +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 (context.len)
> > +		security_release_secctx(&context);
> >  	return NULL;
> >  }
> >  
> > -- 
> > 2.24.1
> > 
> 

-- 
James Morris
<jmorris@namei.org>

[PATCH v22 17/23] 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>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: netdev@vger.kernel.org
---
 include/net/netlabel.h              |  8 +--
 net/ipv4/cipso_ipv4.c               | 26 ++++++----
 net/netlabel/netlabel_kapi.c        |  6 +--
 net/netlabel/netlabel_unlabeled.c   | 79 +++++++++--------------------
 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_access.c       |  2 +-
 security/smack/smack_lsm.c          | 11 ++--
 security/smack/smackfs.c            | 10 ++--
 13 files changed, 68 insertions(+), 86 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 471d33a0d095..1ac343d02b58 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
@@ -1469,7 +1471,11 @@ 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;
+	/* Ensure that there is sufficient space in the CIPSO header
+	 * for the LSM data. */
+	BUILD_BUG_ON(CIPSO_V4_TAG_LOC_BLEN > CIPSO_V4_OPT_LEN_MAX);
+	memcpy(&buffer[2], &secattr->attr.lsmblob,
+	       sizeof(secattr->attr.lsmblob));
 
 	return CIPSO_V4_TAG_LOC_BLEN;
 }
@@ -1489,7 +1495,7 @@ 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 5e1239cef000..bbfaff539416 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 7d426ca1aff6..a84a265635c9 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;
@@ -220,7 +220,7 @@ 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
@@ -231,7 +231,7 @@ 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;
@@ -243,7 +243,7 @@ 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);
@@ -260,7 +260,7 @@ 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
@@ -271,7 +271,7 @@ 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;
@@ -287,7 +287,7 @@ 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);
@@ -366,7 +366,7 @@ 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;
@@ -375,7 +375,6 @@ 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))
@@ -408,7 +407,7 @@ 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,
@@ -421,7 +420,7 @@ 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,
@@ -438,11 +437,7 @@ int netlbl_unlhsh_add(struct net *net,
 unlhsh_add_return:
 	rcu_read_unlock();
 	if (audit_buf != NULL) {
-		/* lsmblob_init() puts secid into all of the secids in blob.
-		 * security_secid_to_secctx() will know which security module
-		 * to use to create the secctx.  */
-		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);
@@ -477,7 +472,6 @@ 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,
@@ -497,13 +491,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
 					  addr->s_addr, mask->s_addr);
 		if (dev != NULL)
 			dev_put(dev);
-		/* lsmblob_init() puts entry->secid into all of the secids
-		 * in blob. security_secid_to_secctx() will know which
-		 * security module to use to create the secctx.  */
-		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);
@@ -544,7 +533,6 @@ 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);
@@ -563,13 +551,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
 					  addr, mask);
 		if (dev != NULL)
 			dev_put(dev);
-		/* lsmblob_init() puts entry->secid into all of the secids
-		 * in blob. security_secid_to_secctx() will know which
-		 * security module to use to create the secctx.  */
-		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);
@@ -923,14 +906,8 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
 	if (ret_val != 0)
 		return ret_val;
 
-	/* netlbl_unlhsh_add will be changed to pass a struct lsmblob *
-	 * instead of a u32 later in this patch set. security_secctx_to_secid()
-	 * will only be setting one entry in the lsmblob struct, so it is
-	 * safe to use lsmblob_value() to get that one value. */
-
-	return netlbl_unlhsh_add(&init_net,
-				 dev_name, addr, mask, addr_len,
-				 lsmblob_value(&blob), &audit_info);
+	return netlbl_unlhsh_add(&init_net, dev_name, addr, mask, addr_len,
+				 &blob, &audit_info);
 }
 
 /**
@@ -977,11 +954,8 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
 	if (ret_val != 0)
 		return ret_val;
 
-	/* security_secctx_to_secid() will only put one secid into the lsmblob
-	 * so it's safe to use lsmblob_value() to get the secid. */
-	return netlbl_unlhsh_add(&init_net,
-				 NULL, addr, mask, addr_len,
-				 lsmblob_value(&blob), &audit_info);
+	return netlbl_unlhsh_add(&init_net, NULL, addr, mask, addr_len, &blob,
+				 &audit_info);
 }
 
 /**
@@ -1093,8 +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,
@@ -1132,7 +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,
@@ -1146,14 +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() secid into all of the secids in blob.
-         * security_secid_to_secctx() will know which security module
-         * to use to create the secctx.  */
-	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,
@@ -1505,7 +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)
@@ -1518,7 +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 9bfc1eea02de..cb124671c15a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6944,7 +6944,7 @@ 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 3cc8bab31ea8..6a40b47307ca 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -73,6 +73,7 @@
 struct netlbl_lsm_secattr;
 
 extern int selinux_enabled_boot;
+extern struct lsm_id selinux_lsmid;
 
 /*
  * type_datum properties
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 9704c8a32303..cdaff603153f 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -3789,7 +3789,7 @@ 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);
@@ -3865,7 +3865,7 @@ 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 0f8d0feb89a4..b06fc332a1f9 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -303,6 +303,7 @@ int smack_populate_secattr(struct smack_known *skp);
  * 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_access.c b/security/smack/smack_access.c
index efe2406a3960..9acb83ce12a8 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -522,7 +522,7 @@ int smack_populate_secattr(struct smack_known *skp)
 {
 	int slen;
 
-	skp->smk_netlabel.attr.secid = skp->smk_secid;
+	skp->smk_netlabel.attr.lsmblob.secid[smack_lsmid.slot] = skp->smk_secid;
 	skp->smk_netlabel.domain = skp->smk_known;
 	skp->smk_netlabel.cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
 	if (skp->smk_netlabel.cache != NULL) {
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index bd03020b3cad..913d41b4b96a 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3721,11 +3721,12 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
 	if ((sap->flags & NETLBL_SECATTR_CACHE) != 0)
 		return (struct smack_known *)sap->cache->data;
 
+	/*
+	 * Looks like a fallback, which gives us a secid.
+	 */
 	if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
-		/*
-		 * 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]);
 
 	if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
 		/*
@@ -4700,7 +4701,7 @@ 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 e567b4baf3a0..139768a13d11 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -1140,6 +1140,7 @@ 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;
@@ -1271,10 +1272,13 @@ 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

[PATCH v22 20/23] Audit: Add new record for multiple process LSM attributes

[Casey Schaufler]

Create a new audit record type to contain the subject information
when there are multiple security modules that require such data.
This record is linked with the same timestamp and serial number
using the audit_alloc_local() mechanism.
The record is produced only in cases where there is more than one
security module with a process "context".
In cases where this record is produced the subj= fields of
other records in the audit event will be set to "subj=?".

An example of the MAC_TASK_CONTEXTS (1420) record is:

        type=UNKNOWN[1420]
        msg=audit(1600880931.832:113)
        subj_apparmor==unconfined
        subj_smack=_

There will be a subj_$LSM= entry for each security module
LSM that supports the secid_to_secctx and secctx_to_secid
hooks. The BPF security module implements secid/secctx
translation hooks, so it has to be considered to provide a
secctx even though it may not actually do so.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: linux-audit@redhat.com
Cc: paul@paul-moore.com
Cc: rgb@redhat.com
Cc: netdev@vger.kernel.org
---
 drivers/android/binder.c                |  2 +-
 include/linux/audit.h                   | 24 ++++++++
 include/linux/security.h                | 18 +++++-
 include/net/netlabel.h                  |  3 +-
 include/net/scm.h                       |  2 +-
 include/net/xfrm.h                      | 13 ++++-
 include/uapi/linux/audit.h              |  1 +
 kernel/audit.c                          | 61 +++++++++++++++------
 kernel/audit.h                          |  2 +
 kernel/auditfilter.c                    |  6 +-
 kernel/auditsc.c                        | 70 +++++++++++++++++++++---
 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_domainhash.c      |  4 +-
 net/netlabel/netlabel_unlabeled.c       | 24 ++++----
 net/netlabel/netlabel_user.c            | 16 ++++--
 net/netlabel/netlabel_user.h            |  6 +-
 net/xfrm/xfrm_policy.c                  | 10 ++--
 net/xfrm/xfrm_state.c                   | 20 ++++---
 security/integrity/ima/ima_api.c        |  7 ++-
 security/integrity/integrity_audit.c    |  6 +-
 security/security.c                     | 73 +++++++++++++++++++------
 security/smack/smackfs.c                |  3 +-
 25 files changed, 281 insertions(+), 100 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index a75ffcd0270a..a4f0cd140612 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3090,7 +3090,7 @@ 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 786d065a64ef..ad1eda37166f 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -164,6 +164,8 @@ extern struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp
 extern __printf(2, 3)
 void audit_log_format(struct audit_buffer *ab, const char *fmt, ...);
 extern void		    audit_log_end(struct audit_buffer *ab);
+extern void		    audit_log_end_local(struct audit_buffer *ab,
+						struct audit_context *context);
 extern bool		    audit_string_contains_control(const char *string,
 							  size_t len);
 extern void		    audit_log_n_hex(struct audit_buffer *ab,
@@ -188,6 +190,7 @@ extern void		    audit_log_lost(const char *message);
 
 extern int audit_log_task_context(struct audit_buffer *ab);
 extern void audit_log_task_info(struct audit_buffer *ab);
+extern void audit_log_lsm(struct audit_context *context);
 
 extern int		    audit_update_lsm_rules(void);
 
@@ -226,6 +229,9 @@ void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
 { }
 static inline void audit_log_end(struct audit_buffer *ab)
 { }
+static inline void audit_log_end_local(struct audit_buffer *ab,
+				       struct audit_context *context)
+{ }
 static inline void audit_log_n_hex(struct audit_buffer *ab,
 				   const unsigned char *buf, size_t len)
 { }
@@ -252,6 +258,8 @@ static inline int audit_log_task_context(struct audit_buffer *ab)
 }
 static inline void audit_log_task_info(struct audit_buffer *ab)
 { }
+static void audit_log_lsm(struct audit_context *context)
+{ }
 
 static inline kuid_t audit_get_loginuid(struct task_struct *tsk)
 {
@@ -291,6 +299,7 @@ extern int  audit_alloc(struct task_struct *task);
 extern void __audit_free(struct task_struct *task);
 extern struct audit_context *audit_alloc_local(gfp_t gfpflags);
 extern void audit_free_context(struct audit_context *context);
+extern void audit_free_local(struct audit_context *context);
 extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1,
 				  unsigned long a2, unsigned long a3);
 extern void __audit_syscall_exit(int ret_success, long ret_value);
@@ -392,6 +401,19 @@ static inline void audit_ptrace(struct task_struct *t)
 		__audit_ptrace(t);
 }
 
+static inline struct audit_context *audit_alloc_for_lsm(gfp_t gfp)
+{
+	struct audit_context *context = audit_context();
+
+	if (context)
+		return context;
+
+	if (lsm_multiple_contexts())
+		return audit_alloc_local(gfp);
+
+	return NULL;
+}
+
 				/* Private API (for audit.c only) */
 extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
 extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode);
@@ -566,6 +588,8 @@ extern int audit_signals;
 }
 static inline void audit_free_context(struct audit_context *context)
 { }
+static inline void audit_free_local(struct audit_context *context)
+{ }
 static inline int audit_alloc(struct task_struct *task)
 {
 	return 0;
diff --git a/include/linux/security.h b/include/linux/security.h
index 20486380c176..3335991e99cb 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -181,6 +181,8 @@ 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.
@@ -243,6 +245,17 @@ static inline u32 lsmblob_value(const struct lsmblob *blob)
 	return 0;
 }
 
+const char *security_lsm_slot_name(int slot);
+
+static inline bool lsm_multiple_contexts(void)
+{
+#ifdef CONFIG_SECURITY
+	return security_lsm_slot_name(1) != NULL;
+#else
+	return false;
+#endif
+}
+
 /* These functions are in security/commoncap.c */
 extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
 		       int cap, unsigned int opts);
@@ -559,7 +572,8 @@ 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);
@@ -1385,7 +1399,7 @@ 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/netlabel.h b/include/net/netlabel.h
index 73fc25b4042b..9bc1f969a25d 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -97,7 +97,8 @@ struct calipso_doi;
 
 /* NetLabel audit information */
 struct netlbl_audit {
-	u32 secid;
+	struct audit_context *localcontext;
+	struct lsmblob lsmdata;
 	kuid_t loginuid;
 	unsigned int sessionid;
 };
diff --git a/include/net/scm.h b/include/net/scm.h
index b77a52f93389..f4d567d4885e 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -101,7 +101,7 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
 		 * and the infrastructure will know which it is.
 		 */
 		lsmblob_init(&lb, scm->secid);
-		err = security_secid_to_secctx(&lb, &context);
+		err = security_secid_to_secctx(&lb, &context, LSMBLOB_DISPLAY);
 
 		if (!err) {
 			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, context.len,
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index b2a06f10b62c..bfe3ba2a5233 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -669,13 +669,22 @@ struct xfrm_spi_skb_cb {
 #define XFRM_SPI_SKB_CB(__skb) ((struct xfrm_spi_skb_cb *)&((__skb)->cb[0]))
 
 #ifdef CONFIG_AUDITSYSCALL
-static inline struct audit_buffer *xfrm_audit_start(const char *op)
+static inline struct audit_buffer *xfrm_audit_start(const char *op,
+						    struct audit_context **lac)
 {
+	struct audit_context *context;
 	struct audit_buffer *audit_buf = NULL;
 
 	if (audit_enabled == AUDIT_OFF)
 		return NULL;
-	audit_buf = audit_log_start(audit_context(), GFP_ATOMIC,
+	context = audit_context();
+	if (lac != NULL) {
+		if (lsm_multiple_contexts() && context == NULL)
+			context = audit_alloc_local(GFP_ATOMIC);
+		*lac = context;
+	}
+
+	audit_buf = audit_log_start(context, GFP_ATOMIC,
 				    AUDIT_MAC_IPSEC_EVENT);
 	if (audit_buf == NULL)
 		return NULL;
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index cd2d8279a5e4..2a63720e56f6 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -139,6 +139,7 @@
 #define AUDIT_MAC_UNLBL_STCDEL	1417	/* NetLabel: del a static label */
 #define AUDIT_MAC_CALIPSO_ADD	1418	/* NetLabel: add CALIPSO DOI entry */
 #define AUDIT_MAC_CALIPSO_DEL	1419	/* NetLabel: del CALIPSO DOI entry */
+#define AUDIT_MAC_TASK_CONTEXTS	1420	/* Multiple LSM contexts */
 
 #define AUDIT_FIRST_KERN_ANOM_MSG   1700
 #define AUDIT_LAST_KERN_ANOM_MSG    1799
diff --git a/kernel/audit.c b/kernel/audit.c
index 4e219d1c1781..554279cb1e20 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -386,10 +386,12 @@ void audit_log_lost(const char *message)
 static int audit_log_config_change(char *function_name, u32 new, u32 old,
 				   int allow_changes)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 	int rc = 0;
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
 	if (unlikely(!ab))
 		return rc;
 	audit_log_format(ab, "op=set %s=%u old=%u ", function_name, new, old);
@@ -398,7 +400,7 @@ 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_end(ab);
+	audit_log_end_local(ab, context);
 	return rc;
 }
 
@@ -1072,12 +1074,6 @@ static void audit_log_common_recv_msg(struct audit_context *context,
 	audit_log_task_context(*ab);
 }
 
-static inline void audit_log_user_recv_msg(struct audit_buffer **ab,
-					   u16 msg_type)
-{
-	audit_log_common_recv_msg(NULL, ab, msg_type);
-}
-
 int is_audit_feature_set(int i)
 {
 	return af.features & AUDIT_FEATURE_TO_MASK(i);
@@ -1349,6 +1345,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 
 		err = audit_filter(msg_type, AUDIT_FILTER_USER);
 		if (err == 1) { /* match or error */
+			struct audit_context *lcontext;
 			char *str = data;
 
 			err = 0;
@@ -1357,7 +1354,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 				if (err)
 					break;
 			}
-			audit_log_user_recv_msg(&ab, msg_type);
+			lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+			audit_log_common_recv_msg(lcontext, &ab, msg_type);
 			if (msg_type != AUDIT_USER_TTY) {
 				/* ensure NULL termination */
 				str[data_len - 1] = '\0';
@@ -1370,7 +1368,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 					data_len--;
 				audit_log_n_untrustedstring(ab, str, data_len);
 			}
-			audit_log_end(ab);
+			audit_log_end_local(ab, lcontext);
 		}
 		break;
 	case AUDIT_ADD_RULE:
@@ -1443,7 +1441,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 
 		if (lsmblob_is_set(&audit_sig_lsm)) {
 			err = security_secid_to_secctx(&audit_sig_lsm,
-						       &context);
+						       &context, LSMBLOB_FIRST);
 			if (err)
 				return err;
 		}
@@ -1550,6 +1548,7 @@ static void audit_receive(struct sk_buff  *skb)
 /* Log information about who is connecting to the audit multicast socket */
 static void audit_log_multicast(int group, const char *op, int err)
 {
+	struct audit_context *context;
 	const struct cred *cred;
 	struct tty_struct *tty;
 	char comm[sizeof(current->comm)];
@@ -1558,7 +1557,8 @@ static void audit_log_multicast(int group, const char *op, int err)
 	if (!audit_enabled)
 		return;
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EVENT_LISTENER);
 	if (!ab)
 		return;
 
@@ -1576,7 +1576,7 @@ static void audit_log_multicast(int group, const char *op, int err)
 	audit_log_untrustedstring(ab, get_task_comm(comm, current));
 	audit_log_d_path_exe(ab, current->mm); /* exe= */
 	audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
-	audit_log_end(ab);
+	audit_log_end_local(ab, context);
 }
 
 /* Run custom bind function on netlink socket group connect or bind requests. */
@@ -2135,7 +2135,19 @@ int audit_log_task_context(struct audit_buffer *ab)
 	if (!lsmblob_is_set(&blob))
 		return 0;
 
-	error = security_secid_to_secctx(&blob, &context);
+	/*
+	 * If there is more than one security module that has a
+	 * subject "context" it's necessary to put the subject data
+	 * into a separate record to maintain compatibility.
+	 */
+	if (lsm_multiple_contexts()) {
+		if (ab->ctx)
+			ab->ctx->lsm = blob;
+		audit_log_format(ab, " subj=?");
+		return 0;
+	}
+
+	error = security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST);
 	if (error) {
 		if (error != -EINVAL)
 			goto error_path;
@@ -2271,6 +2283,7 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
 				   unsigned int oldsessionid,
 				   unsigned int sessionid, int rc)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 	uid_t uid, oldloginuid, loginuid;
 	struct tty_struct *tty;
@@ -2278,7 +2291,8 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
 	if (!audit_enabled)
 		return;
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_LOGIN);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_LOGIN);
 	if (!ab)
 		return;
 
@@ -2293,7 +2307,7 @@ 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_end(ab);
+	audit_log_end_local(ab, context);
 }
 
 /**
@@ -2393,6 +2407,21 @@ void audit_log_end(struct audit_buffer *ab)
 	audit_buffer_free(ab);
 }
 
+/**
+ * audit_log_end_local - end one audit record with local context
+ * @ab: the audit_buffer
+ * @context: the local context
+ *
+ * End an audit event in the usual way, then emit an LSM context
+ * record if approprite.
+ */
+void audit_log_end_local(struct audit_buffer *ab, struct audit_context *context)
+{
+	audit_log_end(ab);
+	audit_log_lsm(context);
+	audit_free_local(context);
+}
+
 /**
  * audit_log - Log an audit record
  * @ctx: audit context
diff --git a/kernel/audit.h b/kernel/audit.h
index 3f2285e1c6e0..624828a9a7e4 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -131,6 +131,7 @@ struct audit_context {
 	kgid_t		    gid, egid, sgid, fsgid;
 	unsigned long	    personality;
 	int		    arch;
+	struct lsmblob	    lsm;
 
 	pid_t		    target_pid;
 	kuid_t		    target_auid;
@@ -201,6 +202,7 @@ struct audit_context {
 extern bool audit_ever_enabled;
 
 extern void audit_log_session_info(struct audit_buffer *ab);
+extern void audit_log_lsm(struct audit_context *context);
 
 extern int auditd_test_task(struct task_struct *task);
 
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 9e73a7961665..2b0a6fda767d 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1098,12 +1098,14 @@ static void audit_list_rules(int seq, struct sk_buff_head *q)
 /* Log rule additions and removals */
 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 
 	if (!audit_enabled)
 		return;
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
 	if (!ab)
 		return;
 	audit_log_session_info(ab);
@@ -1111,7 +1113,7 @@ 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_end(ab);
+	audit_log_end_local(ab, context);
 }
 
 /**
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 5bfee5d0812d..44b150432147 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -989,12 +989,11 @@ struct audit_context *audit_alloc_local(gfp_t gfpflags)
 	context = audit_alloc_context(AUDIT_RECORD_CONTEXT, gfpflags);
 	if (!context) {
 		audit_log_lost("out of memory in audit_alloc_local");
-		goto out;
+		return NULL;
 	}
 	context->serial = audit_serial();
 	ktime_get_coarse_real_ts64(&context->ctime);
 	context->local = true;
-out:
 	return context;
 }
 EXPORT_SYMBOL(audit_alloc_local);
@@ -1015,6 +1014,13 @@ void audit_free_context(struct audit_context *context)
 }
 EXPORT_SYMBOL(audit_free_context);
 
+void audit_free_local(struct audit_context *context)
+{
+	if (context && context->local)
+		audit_free_context(context);
+}
+EXPORT_SYMBOL(audit_free_local);
+
 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 				 kuid_t auid, kuid_t uid,
 				 unsigned int sessionid,
@@ -1032,7 +1038,7 @@ 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 {
@@ -1277,7 +1283,8 @@ 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 {
@@ -1429,7 +1436,7 @@ 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;
@@ -1506,6 +1513,45 @@ static void audit_log_proctitle(void)
 	audit_log_end(ab);
 }
 
+void audit_log_lsm(struct audit_context *context)
+{
+	struct audit_buffer *ab;
+	struct lsmcontext lsmdata;
+	bool sep = false;
+	int error;
+	int i;
+
+	if (!lsm_multiple_contexts())
+		return;
+
+	if (context == NULL)
+		return;
+
+	if (!lsmblob_is_set(&context->lsm))
+		return;
+
+	ab = audit_log_start(context, GFP_ATOMIC, AUDIT_MAC_TASK_CONTEXTS);
+	if (!ab)
+		return; /* audit_panic or being filtered */
+
+	for (i = 0; i < LSMBLOB_ENTRIES; i++) {
+		if (context->lsm.secid[i] == 0)
+			continue;
+		error = security_secid_to_secctx(&context->lsm, &lsmdata, i);
+		if (error && error != -EINVAL) {
+			audit_panic("error in audit_log_lsm");
+			return;
+		}
+
+		audit_log_format(ab, "%ssubj_%s=%s", sep ? " " : "",
+				 security_lsm_slot_name(i), lsmdata.context);
+		sep = true;
+
+		security_release_secctx(&lsmdata);
+	}
+	audit_log_end(ab);
+}
+
 static void audit_log_exit(void)
 {
 	int i, call_panic = 0;
@@ -1630,6 +1676,8 @@ static void audit_log_exit(void)
 
 	audit_log_proctitle();
 
+	audit_log_lsm(context);
+
 	/* Send end of event record to help user space know we are finished */
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
 	if (ab)
@@ -2635,10 +2683,12 @@ void __audit_ntp_log(const struct audit_ntp_data *ad)
 void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
 		       enum audit_nfcfgop op, gfp_t gfp)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 	char comm[sizeof(current->comm)];
 
-	ab = audit_log_start(audit_context(), gfp, AUDIT_NETFILTER_CFG);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, gfp, AUDIT_NETFILTER_CFG);
 	if (!ab)
 		return;
 	audit_log_format(ab, "table=%s family=%u entries=%u op=%s",
@@ -2648,7 +2698,7 @@ void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
 	audit_log_task_context(ab); /* subj= */
 	audit_log_format(ab, " comm=");
 	audit_log_untrustedstring(ab, get_task_comm(comm, current));
-	audit_log_end(ab);
+	audit_log_end_local(ab, context);
 }
 EXPORT_SYMBOL_GPL(__audit_log_nfcfg);
 
@@ -2683,6 +2733,7 @@ static void audit_log_task(struct audit_buffer *ab)
  */
 void audit_core_dumps(long signr)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 
 	if (!audit_enabled)
@@ -2691,12 +2742,13 @@ void audit_core_dumps(long signr)
 	if (signr == SIGQUIT)	/* don't care for those */
 		return;
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_ABEND);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_ANOM_ABEND);
 	if (unlikely(!ab))
 		return;
 	audit_log_task(ab);
 	audit_log_format(ab, " sig=%ld res=1", signr);
-	audit_log_end(ab);
+	audit_log_end_local(ab, context);
 }
 
 /**
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index ae073b642fa7..5c0029a3a595 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -140,7 +140,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 		return;
 
 	lsmblob_init(&lb, secid);
-	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 e6fdcd87ab3e..b63ecc7185fc 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -339,7 +339,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
 	 * security_secid_to_secctx() will know which security module
 	 * to use to create the secctx.  */
 	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;
 
@@ -655,7 +655,7 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
 	struct lsmblob blob;
 	struct lsmcontext context;
 
-	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 c6112960fc73..2cb3a8df7932 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 0d8b83d84422..f2dffeed4789 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -316,7 +316,7 @@ static void nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context)
 		 * blob. security_secid_to_secctx() will know which security
 		 * module to use to create the secctx.  */
 		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_domainhash.c b/net/netlabel/netlabel_domainhash.c
index dc8c39f51f7d..2690a528d262 100644
--- a/net/netlabel/netlabel_domainhash.c
+++ b/net/netlabel/netlabel_domainhash.c
@@ -259,7 +259,7 @@ static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry,
 			break;
 		}
 		audit_log_format(audit_buf, " res=%u", result == 0 ? 1 : 0);
-		audit_log_end(audit_buf);
+		audit_log_end_local(audit_buf, audit_info->localcontext);
 	}
 }
 
@@ -614,7 +614,7 @@ int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry,
 		audit_log_format(audit_buf,
 				 " nlbl_domain=%s res=1",
 				 entry->domain ? entry->domain : "(default)");
-		audit_log_end(audit_buf);
+		audit_log_end_local(audit_buf, audit_info->localcontext);
 	}
 
 	switch (entry->def.type) {
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index a84a265635c9..853b989da239 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -437,13 +437,14 @@ 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);
 		}
 		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
-		audit_log_end(audit_buf);
+		audit_log_end_local(audit_buf, audit_info->localcontext);
 	}
 	return ret_val;
 }
@@ -492,13 +493,14 @@ 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);
 		}
 		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
-		audit_log_end(audit_buf);
+		audit_log_end_local(audit_buf, audit_info->localcontext);
 	}
 
 	if (entry == NULL)
@@ -552,13 +554,14 @@ 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);
 		}
 		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
-		audit_log_end(audit_buf);
+		audit_log_end_local(audit_buf, audit_info->localcontext);
 	}
 
 	if (entry == NULL)
@@ -741,7 +744,7 @@ static void netlbl_unlabel_acceptflg_set(u8 value,
 	if (audit_buf != NULL) {
 		audit_log_format(audit_buf,
 				 " unlbl_accept=%u old=%u", value, old_val);
-		audit_log_end(audit_buf);
+		audit_log_end_local(audit_buf, audit_info->localcontext);
 	}
 }
 
@@ -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,
@@ -1521,14 +1524,11 @@ 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, &blob);
-	/* scaffolding until audit_info.secid is converted */
-	audit_info.secid = blob.secid[0];
+	security_task_getsecid(current, &audit_info.lsmdata);
 	audit_info.loginuid = GLOBAL_ROOT_UID;
 	audit_info.sessionid = 0;
 
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 951ba0639d20..4fb4c37cc4a7 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -83,14 +83,17 @@ int __init netlbl_netlink_init(void)
 struct audit_buffer *netlbl_audit_start_common(int type,
 					       struct netlbl_audit *audit_info)
 {
+	struct audit_context *audit_ctx;
 	struct audit_buffer *audit_buf;
 	struct lsmcontext context;
-	struct lsmblob blob;
 
 	if (audit_enabled == AUDIT_OFF)
 		return NULL;
 
-	audit_buf = audit_log_start(audit_context(), GFP_ATOMIC, type);
+	audit_ctx = audit_alloc_for_lsm(GFP_ATOMIC);
+	audit_info->localcontext = audit_ctx;
+
+	audit_buf = audit_log_start(audit_ctx, GFP_ATOMIC, type);
 	if (audit_buf == NULL)
 		return NULL;
 
@@ -98,12 +101,13 @@ 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(&blob, &context) == 0) {
+	if (!lsm_multiple_contexts() && lsmblob_is_set(&audit_info->lsmdata) &&
+	    security_secid_to_secctx(&audit_info->lsmdata, &context,
+				     LSMBLOB_FIRST) == 0) {
 		audit_log_format(audit_buf, " subj=%s", context.context);
 		security_release_secctx(&context);
-	}
+	} else
+		audit_log_format(audit_buf, " subj=?");
 
 	return audit_buf;
 }
diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
index 438b5db6c714..bd4335443b87 100644
--- a/net/netlabel/netlabel_user.h
+++ b/net/netlabel/netlabel_user.h
@@ -34,11 +34,7 @@
 static inline void netlbl_netlink_auditinfo(struct sk_buff *skb,
 					    struct netlbl_audit *audit_info)
 {
-	struct lsmblob blob;
-
-	security_task_getsecid(current, &blob);
-	/* scaffolding until secid is converted */
-	audit_info->secid = blob.secid[0];
+	security_task_getsecid(current, &audit_info->lsmdata);
 	audit_info->loginuid = audit_get_loginuid(current);
 	audit_info->sessionid = audit_get_sessionid(current);
 }
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index d622c2548d22..6aa4bcc08848 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -4205,30 +4205,32 @@ static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,
 
 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
 {
+	struct audit_context *context;
 	struct audit_buffer *audit_buf;
 
-	audit_buf = xfrm_audit_start("SPD-add");
+	audit_buf = xfrm_audit_start("SPD-add", &context);
 	if (audit_buf == NULL)
 		return;
 	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_end(audit_buf);
+	audit_log_end_local(audit_buf, context);
 }
 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
 
 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
 			      bool task_valid)
 {
+	struct audit_context *context;
 	struct audit_buffer *audit_buf;
 
-	audit_buf = xfrm_audit_start("SPD-delete");
+	audit_buf = xfrm_audit_start("SPD-delete", &context);
 	if (audit_buf == NULL)
 		return;
 	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_end(audit_buf);
+	audit_log_end_local(audit_buf, context);
 }
 EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
 #endif
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index bbd4643d7e82..ffb75b23f261 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2740,29 +2740,31 @@ static void xfrm_audit_helper_pktinfo(struct sk_buff *skb, u16 family,
 
 void xfrm_audit_state_add(struct xfrm_state *x, int result, bool task_valid)
 {
+	struct audit_context *context;
 	struct audit_buffer *audit_buf;
 
-	audit_buf = xfrm_audit_start("SAD-add");
+	audit_buf = xfrm_audit_start("SAD-add", &context);
 	if (audit_buf == NULL)
 		return;
 	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_end(audit_buf);
+	audit_log_end_local(audit_buf, context);
 }
 EXPORT_SYMBOL_GPL(xfrm_audit_state_add);
 
 void xfrm_audit_state_delete(struct xfrm_state *x, int result, bool task_valid)
 {
+	struct audit_context *context;
 	struct audit_buffer *audit_buf;
 
-	audit_buf = xfrm_audit_start("SAD-delete");
+	audit_buf = xfrm_audit_start("SAD-delete", &context);
 	if (audit_buf == NULL)
 		return;
 	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_end(audit_buf);
+	audit_log_end_local(audit_buf, context);
 }
 EXPORT_SYMBOL_GPL(xfrm_audit_state_delete);
 
@@ -2772,7 +2774,7 @@ void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
 	struct audit_buffer *audit_buf;
 	u32 spi;
 
-	audit_buf = xfrm_audit_start("SA-replay-overflow");
+	audit_buf = xfrm_audit_start("SA-replay-overflow", NULL);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
@@ -2790,7 +2792,7 @@ void xfrm_audit_state_replay(struct xfrm_state *x,
 	struct audit_buffer *audit_buf;
 	u32 spi;
 
-	audit_buf = xfrm_audit_start("SA-replayed-pkt");
+	audit_buf = xfrm_audit_start("SA-replayed-pkt", NULL);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
@@ -2805,7 +2807,7 @@ void xfrm_audit_state_notfound_simple(struct sk_buff *skb, u16 family)
 {
 	struct audit_buffer *audit_buf;
 
-	audit_buf = xfrm_audit_start("SA-notfound");
+	audit_buf = xfrm_audit_start("SA-notfound", NULL);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_pktinfo(skb, family, audit_buf);
@@ -2819,7 +2821,7 @@ void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family,
 	struct audit_buffer *audit_buf;
 	u32 spi;
 
-	audit_buf = xfrm_audit_start("SA-notfound");
+	audit_buf = xfrm_audit_start("SA-notfound", NULL);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_pktinfo(skb, family, audit_buf);
@@ -2837,7 +2839,7 @@ void xfrm_audit_state_icvfail(struct xfrm_state *x,
 	__be32 net_spi;
 	__be32 net_seq;
 
-	audit_buf = xfrm_audit_start("SA-icv-failure");
+	audit_buf = xfrm_audit_start("SA-icv-failure", NULL);
 	if (audit_buf == NULL)
 		return;
 	xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index e83fa1c32843..8b6f8402703d 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -340,6 +340,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
 void ima_audit_measurement(struct integrity_iint_cache *iint,
 			   const unsigned char *filename)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 	char *hash;
 	const char *algo_name = hash_algo_name[iint->ima_hash->algo];
@@ -356,8 +357,8 @@ void ima_audit_measurement(struct integrity_iint_cache *iint,
 		hex_byte_pack(hash + (i * 2), iint->ima_hash->digest[i]);
 	hash[i * 2] = '\0';
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL,
-			     AUDIT_INTEGRITY_RULE);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
 	if (!ab)
 		goto out;
 
@@ -366,7 +367,7 @@ 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_end(ab);
+	audit_log_end_local(ab, context);
 
 	iint->flags |= IMA_AUDITED;
 out:
diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c
index 29220056207f..b38163c43659 100644
--- a/security/integrity/integrity_audit.c
+++ b/security/integrity/integrity_audit.c
@@ -38,13 +38,15 @@ void integrity_audit_message(int audit_msgno, struct inode *inode,
 			     const char *cause, int result, int audit_info,
 			     int errno)
 {
+	struct audit_context *context;
 	struct audit_buffer *ab;
 	char name[TASK_COMM_LEN];
 
 	if (!integrity_audit_info && audit_info == 1)	/* Skip info messages */
 		return;
 
-	ab = audit_log_start(audit_context(), GFP_KERNEL, audit_msgno);
+	context = audit_alloc_for_lsm(GFP_KERNEL);
+	ab = audit_log_start(context, GFP_KERNEL, audit_msgno);
 	audit_log_format(ab, "pid=%d uid=%u auid=%u ses=%u",
 			 task_pid_nr(current),
 			 from_kuid(&init_user_ns, current_uid()),
@@ -63,5 +65,5 @@ void integrity_audit_message(int audit_msgno, struct inode *inode,
 		audit_log_format(ab, " ino=%lu", inode->i_ino);
 	}
 	audit_log_format(ab, " res=%d errno=%d", !result, errno);
-	audit_log_end(ab);
+	audit_log_end_local(ab, context);
 }
diff --git a/security/security.c b/security/security.c
index c6b0f854c4a3..1a78f7bb808b 100644
--- a/security/security.c
+++ b/security/security.c
@@ -483,7 +483,31 @@ 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.
@@ -2193,7 +2217,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
 		hlist_for_each_entry(hp, &security_hook_heads.setprocattr,
 				     list) {
 			rc = hp->hook.setprocattr(name, value, size);
-			if (rc < 0)
+			if (rc < 0 && rc != -EINVAL)
 				return rc;
 		}
 
@@ -2238,13 +2262,32 @@ 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: %s unknown display\n", __func__);
+		display = LSMBLOB_INVALID;
+	} else if (display >= lsm_slot) {
+		WARN_ONCE(true,
+			"LSM: %s invalid display\n", __func__);
+		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;
@@ -2274,7 +2317,7 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
 			return hp->hook.secctx_to_secid(secdata, seclen,
 						&blob->secid[hp->lsmid->slot]);
 	}
-	return 0;
+	return -EOPNOTSUPP;
 }
 EXPORT_SYMBOL(security_secctx_to_secid);
 
@@ -2767,23 +2810,17 @@ int security_key_getsecurity(struct key *key, char **_buffer)
 int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
 {
 	struct security_hook_list *hp;
-	bool one_is_good = false;
-	int rc = 0;
-	int trc;
+	int display = lsm_task_display(current);
 
 	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 (display != LSMBLOB_INVALID && display != hp->lsmid->slot)
+			continue;
+		return hp->hook.audit_rule_init(field, op, rulestr,
+						&lsmrule[hp->lsmid->slot]);
 	}
-	if (one_is_good)
-		return 0;
-	return rc;
+	return 0;
 }
 
 int security_audit_rule_known(struct audit_krule *krule)
@@ -2815,6 +2852,8 @@ int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
 			continue;
 		if (lsmrule[hp->lsmid->slot] == NULL)
 			continue;
+		if (lsmrule[hp->lsmid->slot] == NULL)
+			continue;
 		rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
 					       field, op,
 					       &lsmrule[hp->lsmid->slot]);
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 139768a13d11..17391258e896 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -185,7 +185,8 @@ static void smk_netlabel_audit_set(struct netlbl_audit *nap)
 
 	nap->loginuid = audit_get_loginuid(current);
 	nap->sessionid = audit_get_sessionid(current);
-	nap->secid = skp->smk_secid;
+	lsmblob_init(&nap->lsmdata, 0);
+	nap->lsmdata.secid[smack_lsmid.slot] = skp->smk_secid;
 }
 
 /*
-- 
2.24.1