Merge remote-tracking branch 'stable/linux-3.12.y' into sdk-v1.6.x

Signed-off-by: Scott Wood <scottwood@freescale.com>

Conflicts:
	drivers/mmc/card/block.c

12 files changed, 244 insertions, 76 deletions

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 399433a..a9c3d3c 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -73,7 +73,6 @@ static struct ima_rule_entry default_rules[] = {
 	{.action = DONT_MEASURE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
 	{.action = DONT_MEASURE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
 	{.action = DONT_MEASURE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC},
-	{.action = DONT_MEASURE,.fsmagic = RAMFS_MAGIC,.flags = IMA_FSMAGIC},
 	{.action = DONT_MEASURE,.fsmagic = DEVPTS_SUPER_MAGIC,.flags = IMA_FSMAGIC},
 	{.action = DONT_MEASURE,.fsmagic = BINFMTFS_MAGIC,.flags = IMA_FSMAGIC},
 	{.action = DONT_MEASURE,.fsmagic = SECURITYFS_MAGIC,.flags = IMA_FSMAGIC},
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 5b52310..25d5eba 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -53,6 +53,7 @@
 #include <net/ip.h>		/* for local_port_range[] */
 #include <net/sock.h>
 #include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
+#include <net/inet_connection_sock.h>
 #include <net/net_namespace.h>
 #include <net/netlabel.h>
 #include <linux/uaccess.h>
@@ -219,6 +220,14 @@ static int inode_alloc_security(struct inode *inode)
 	return 0;
 }
 
+static void inode_free_rcu(struct rcu_head *head)
+{
+	struct inode_security_struct *isec;
+
+	isec = container_of(head, struct inode_security_struct, rcu);
+	kmem_cache_free(sel_inode_cache, isec);
+}
+
 static void inode_free_security(struct inode *inode)
 {
 	struct inode_security_struct *isec = inode->i_security;
@@ -229,8 +238,16 @@ static void inode_free_security(struct inode *inode)
 		list_del_init(&isec->list);
 	spin_unlock(&sbsec->isec_lock);
 
-	inode->i_security = NULL;
-	kmem_cache_free(sel_inode_cache, isec);
+	/*
+	 * The inode may still be referenced in a path walk and
+	 * a call to selinux_inode_permission() can be made
+	 * after inode_free_security() is called. Ideally, the VFS
+	 * wouldn't do this, but fixing that is a much harder
+	 * job. For now, simply free the i_security via RCU, and
+	 * leave the current inode->i_security pointer intact.
+	 * The inode will be freed after the RCU grace period too.
+	 */
+	call_rcu(&isec->rcu, inode_free_rcu);
 }
 
 static int file_alloc_security(struct file *file)
@@ -3791,7 +3808,7 @@ static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
 	u32 nlbl_sid;
 	u32 nlbl_type;
 
-	selinux_skb_xfrm_sid(skb, &xfrm_sid);
+	selinux_xfrm_skb_sid(skb, &xfrm_sid);
 	selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
 
 	err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
@@ -3805,6 +3822,30 @@ static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
 	return 0;
 }
 
+/**
+ * selinux_conn_sid - Determine the child socket label for a connection
+ * @sk_sid: the parent socket's SID
+ * @skb_sid: the packet's SID
+ * @conn_sid: the resulting connection SID
+ *
+ * If @skb_sid is valid then the user:role:type information from @sk_sid is
+ * combined with the MLS information from @skb_sid in order to create
+ * @conn_sid.  If @skb_sid is not valid then then @conn_sid is simply a copy
+ * of @sk_sid.  Returns zero on success, negative values on failure.
+ *
+ */
+static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
+{
+	int err = 0;
+
+	if (skb_sid != SECSID_NULL)
+		err = security_sid_mls_copy(sk_sid, skb_sid, conn_sid);
+	else
+		*conn_sid = sk_sid;
+
+	return err;
+}
+
 /* socket security operations */
 
 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
@@ -4272,8 +4313,10 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 		}
 		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
 				   PEER__RECV, &ad);
-		if (err)
+		if (err) {
 			selinux_netlbl_err(skb, err, 0);
+			return err;
+		}
 	}
 
 	if (secmark_active) {
@@ -4411,7 +4454,7 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 	struct sk_security_struct *sksec = sk->sk_security;
 	int err;
 	u16 family = sk->sk_family;
-	u32 newsid;
+	u32 connsid;
 	u32 peersid;
 
 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
@@ -4421,16 +4464,11 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 	err = selinux_skb_peerlbl_sid(skb, family, &peersid);
 	if (err)
 		return err;
-	if (peersid == SECSID_NULL) {
-		req->secid = sksec->sid;
-		req->peer_secid = SECSID_NULL;
-	} else {
-		err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
-		if (err)
-			return err;
-		req->secid = newsid;
-		req->peer_secid = peersid;
-	}
+	err = selinux_conn_sid(sksec->sid, peersid, &connsid);
+	if (err)
+		return err;
+	req->secid = connsid;
+	req->peer_secid = peersid;
 
 	return selinux_netlbl_inet_conn_request(req, family);
 }
@@ -4690,6 +4728,7 @@ static unsigned int selinux_ipv6_forward(unsigned int hooknum,
 static unsigned int selinux_ip_output(struct sk_buff *skb,
 				      u16 family)
 {
+	struct sock *sk;
 	u32 sid;
 
 	if (!netlbl_enabled())
@@ -4698,8 +4737,27 @@ static unsigned int selinux_ip_output(struct sk_buff *skb,
 	/* we do this in the LOCAL_OUT path and not the POST_ROUTING path
 	 * because we want to make sure we apply the necessary labeling
 	 * before IPsec is applied so we can leverage AH protection */
-	if (skb->sk) {
-		struct sk_security_struct *sksec = skb->sk->sk_security;
+	sk = skb->sk;
+	if (sk) {
+		struct sk_security_struct *sksec;
+
+		if (sk->sk_state == TCP_LISTEN)
+			/* if the socket is the listening state then this
+			 * packet is a SYN-ACK packet which means it needs to
+			 * be labeled based on the connection/request_sock and
+			 * not the parent socket.  unfortunately, we can't
+			 * lookup the request_sock yet as it isn't queued on
+			 * the parent socket until after the SYN-ACK is sent.
+			 * the "solution" is to simply pass the packet as-is
+			 * as any IP option based labeling should be copied
+			 * from the initial connection request (in the IP
+			 * layer).  it is far from ideal, but until we get a
+			 * security label in the packet itself this is the
+			 * best we can do. */
+			return NF_ACCEPT;
+
+		/* standard practice, label using the parent socket */
+		sksec = sk->sk_security;
 		sid = sksec->sid;
 	} else
 		sid = SECINITSID_KERNEL;
@@ -4769,27 +4827,37 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
 	 * as fast and as clean as possible. */
 	if (!selinux_policycap_netpeer)
 		return selinux_ip_postroute_compat(skb, ifindex, family);
+
+	secmark_active = selinux_secmark_enabled();
+	peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
+	if (!secmark_active && !peerlbl_active)
+		return NF_ACCEPT;
+
+	sk = skb->sk;
+
 #ifdef CONFIG_XFRM
 	/* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
 	 * packet transformation so allow the packet to pass without any checks
 	 * since we'll have another chance to perform access control checks
 	 * when the packet is on it's final way out.
 	 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
-	 *       is NULL, in this case go ahead and apply access control. */
-	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)
+	 *       is NULL, in this case go ahead and apply access control.
+	 *       is NULL, in this case go ahead and apply access control.
+	 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
+	 *       TCP listening state we cannot wait until the XFRM processing
+	 *       is done as we will miss out on the SA label if we do;
+	 *       unfortunately, this means more work, but it is only once per
+	 *       connection. */
+	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
+	    !(sk != NULL && sk->sk_state == TCP_LISTEN))
 		return NF_ACCEPT;
 #endif
-	secmark_active = selinux_secmark_enabled();
-	peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
-	if (!secmark_active && !peerlbl_active)
-		return NF_ACCEPT;
 
-	/* if the packet is being forwarded then get the peer label from the
-	 * packet itself; otherwise check to see if it is from a local
-	 * application or the kernel, if from an application get the peer label
-	 * from the sending socket, otherwise use the kernel's sid */
-	sk = skb->sk;
 	if (sk == NULL) {
+		/* Without an associated socket the packet is either coming
+		 * from the kernel or it is being forwarded; check the packet
+		 * to determine which and if the packet is being forwarded
+		 * query the packet directly to determine the security label. */
 		if (skb->skb_iif) {
 			secmark_perm = PACKET__FORWARD_OUT;
 			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
@@ -4798,7 +4866,45 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
 			secmark_perm = PACKET__SEND;
 			peer_sid = SECINITSID_KERNEL;
 		}
+	} else if (sk->sk_state == TCP_LISTEN) {
+		/* Locally generated packet but the associated socket is in the
+		 * listening state which means this is a SYN-ACK packet.  In
+		 * this particular case the correct security label is assigned
+		 * to the connection/request_sock but unfortunately we can't
+		 * query the request_sock as it isn't queued on the parent
+		 * socket until after the SYN-ACK packet is sent; the only
+		 * viable choice is to regenerate the label like we do in
+		 * selinux_inet_conn_request().  See also selinux_ip_output()
+		 * for similar problems. */
+		u32 skb_sid;
+		struct sk_security_struct *sksec = sk->sk_security;
+		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
+			return NF_DROP;
+		/* At this point, if the returned skb peerlbl is SECSID_NULL
+		 * and the packet has been through at least one XFRM
+		 * transformation then we must be dealing with the "final"
+		 * form of labeled IPsec packet; since we've already applied
+		 * all of our access controls on this packet we can safely
+		 * pass the packet. */
+		if (skb_sid == SECSID_NULL) {
+			switch (family) {
+			case PF_INET:
+				if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
+					return NF_ACCEPT;
+				break;
+			case PF_INET6:
+				if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
+					return NF_ACCEPT;
+			default:
+				return NF_DROP_ERR(-ECONNREFUSED);
+			}
+		}
+		if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
+			return NF_DROP;
+		secmark_perm = PACKET__SEND;
 	} else {
+		/* Locally generated packet, fetch the security label from the
+		 * associated socket. */
 		struct sk_security_struct *sksec = sk->sk_security;
 		peer_sid = sksec->sid;
 		secmark_perm = PACKET__SEND;
@@ -5462,11 +5568,11 @@ static int selinux_setprocattr(struct task_struct *p,
 		/* Check for ptracing, and update the task SID if ok.
 		   Otherwise, leave SID unchanged and fail. */
 		ptsid = 0;
-		task_lock(p);
+		rcu_read_lock();
 		tracer = ptrace_parent(p);
 		if (tracer)
 			ptsid = task_sid(tracer);
-		task_unlock(p);
+		rcu_read_unlock();
 
 		if (tracer) {
 			error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index aa47bca..6fd9dd2 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -38,7 +38,10 @@ struct task_security_struct {
 
 struct inode_security_struct {
 	struct inode *inode;	/* back pointer to inode object */
-	struct list_head list;	/* list of inode_security_struct */
+	union {
+		struct list_head list;	/* list of inode_security_struct */
+		struct rcu_head rcu;	/* for freeing the inode_security_struct */
+	};
 	u32 task_sid;		/* SID of creating task */
 	u32 sid;		/* SID of this object */
 	u16 sclass;		/* security class of this object */
diff --git a/security/selinux/include/xfrm.h b/security/selinux/include/xfrm.h
index 6713f04..c1af4e1 100644
--- a/security/selinux/include/xfrm.h
+++ b/security/selinux/include/xfrm.h
@@ -47,6 +47,7 @@ int selinux_xfrm_sock_rcv_skb(u32 sid, struct sk_buff *skb,
 int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb,
 			struct common_audit_data *ad, u8 proto);
 int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall);
+int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid);
 
 static inline void selinux_xfrm_notify_policyload(void)
 {
@@ -85,12 +86,12 @@ static inline int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int
 static inline void selinux_xfrm_notify_policyload(void)
 {
 }
-#endif
 
-static inline void selinux_skb_xfrm_sid(struct sk_buff *skb, u32 *sid)
+static inline int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid)
 {
-	int err = selinux_xfrm_decode_session(skb, sid, 0);
-	BUG_ON(err);
+	*sid = SECSID_NULL;
+	return 0;
 }
+#endif
 
 #endif /* _SELINUX_XFRM_H_ */
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index da4b8b2..6235d05 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -442,8 +442,7 @@ int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
 	    sksec->nlbl_state != NLBL_CONNLABELED)
 		return 0;
 
-	local_bh_disable();
-	bh_lock_sock_nested(sk);
+	lock_sock(sk);
 
 	/* connected sockets are allowed to disconnect when the address family
 	 * is set to AF_UNSPEC, if that is what is happening we want to reset
@@ -464,7 +463,6 @@ int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
 		sksec->nlbl_state = NLBL_CONNLABELED;
 
 socket_connect_return:
-	bh_unlock_sock(sk);
-	local_bh_enable();
+	release_sock(sk);
 	return rc;
 }
diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c
index 30f119b..820313a 100644
--- a/security/selinux/ss/ebitmap.c
+++ b/security/selinux/ss/ebitmap.c
@@ -213,7 +213,12 @@ netlbl_import_failure:
 }
 #endif /* CONFIG_NETLABEL */
 
-int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2)
+/*
+ * Check to see if all the bits set in e2 are also set in e1. Optionally,
+ * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed
+ * last_e2bit.
+ */
+int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit)
 {
 	struct ebitmap_node *n1, *n2;
 	int i;
@@ -223,14 +228,25 @@ int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2)
 
 	n1 = e1->node;
 	n2 = e2->node;
+
 	while (n1 && n2 && (n1->startbit <= n2->startbit)) {
 		if (n1->startbit < n2->startbit) {
 			n1 = n1->next;
 			continue;
 		}
-		for (i = 0; i < EBITMAP_UNIT_NUMS; i++) {
+		for (i = EBITMAP_UNIT_NUMS - 1; (i >= 0) && !n2->maps[i]; )
+			i--;	/* Skip trailing NULL map entries */
+		if (last_e2bit && (i >= 0)) {
+			u32 lastsetbit = n2->startbit + i * EBITMAP_UNIT_SIZE +
+					 __fls(n2->maps[i]);
+			if (lastsetbit > last_e2bit)
+				return 0;
+		}
+
+		while (i >= 0) {
 			if ((n1->maps[i] & n2->maps[i]) != n2->maps[i])
 				return 0;
+			i--;
 		}
 
 		n1 = n1->next;
diff --git a/security/selinux/ss/ebitmap.h b/security/selinux/ss/ebitmap.h
index 922f8af..712c8a7 100644
--- a/security/selinux/ss/ebitmap.h
+++ b/security/selinux/ss/ebitmap.h
@@ -16,7 +16,13 @@
 
 #include <net/netlabel.h>
 
-#define EBITMAP_UNIT_NUMS	((32 - sizeof(void *) - sizeof(u32))	\
+#ifdef CONFIG_64BIT
+#define	EBITMAP_NODE_SIZE	64
+#else
+#define	EBITMAP_NODE_SIZE	32
+#endif
+
+#define EBITMAP_UNIT_NUMS	((EBITMAP_NODE_SIZE-sizeof(void *)-sizeof(u32))\
 					/ sizeof(unsigned long))
 #define EBITMAP_UNIT_SIZE	BITS_PER_LONG
 #define EBITMAP_SIZE		(EBITMAP_UNIT_NUMS * EBITMAP_UNIT_SIZE)
@@ -117,7 +123,7 @@ static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
 
 int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
 int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
-int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2);
+int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit);
 int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
 void ebitmap_destroy(struct ebitmap *e);
diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index 40de8d3..c85bc1e 100644
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -160,8 +160,6 @@ void mls_sid_to_context(struct context *context,
 int mls_level_isvalid(struct policydb *p, struct mls_level *l)
 {
 	struct level_datum *levdatum;
-	struct ebitmap_node *node;
-	int i;
 
 	if (!l->sens || l->sens > p->p_levels.nprim)
 		return 0;
@@ -170,19 +168,13 @@ int mls_level_isvalid(struct policydb *p, struct mls_level *l)
 	if (!levdatum)
 		return 0;
 
-	ebitmap_for_each_positive_bit(&l->cat, node, i) {
-		if (i > p->p_cats.nprim)
-			return 0;
-		if (!ebitmap_get_bit(&levdatum->level->cat, i)) {
-			/*
-			 * Category may not be associated with
-			 * sensitivity.
-			 */
-			return 0;
-		}
-	}
-
-	return 1;
+	/*
+	 * Return 1 iff all the bits set in l->cat are also be set in
+	 * levdatum->level->cat and no bit in l->cat is larger than
+	 * p->p_cats.nprim.
+	 */
+	return ebitmap_contains(&levdatum->level->cat, &l->cat,
+				p->p_cats.nprim);
 }
 
 int mls_range_isvalid(struct policydb *p, struct mls_range *r)
diff --git a/security/selinux/ss/mls_types.h b/security/selinux/ss/mls_types.h
index 03bed52..e936487 100644
--- a/security/selinux/ss/mls_types.h
+++ b/security/selinux/ss/mls_types.h
@@ -35,7 +35,7 @@ static inline int mls_level_eq(struct mls_level *l1, struct mls_level *l2)
 static inline int mls_level_dom(struct mls_level *l1, struct mls_level *l2)
 {
 	return ((l1->sens >= l2->sens) &&
-		ebitmap_contains(&l1->cat, &l2->cat));
+		ebitmap_contains(&l1->cat, &l2->cat, 0));
 }
 
 #define mls_level_incomp(l1, l2) \
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index c8adde3..4d35eb7 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -1941,7 +1941,19 @@ static int filename_trans_read(struct policydb *p, void *fp)
 		if (rc)
 			goto out;
 
-		hashtab_insert(p->filename_trans, ft, otype);
+		rc = hashtab_insert(p->filename_trans, ft, otype);
+		if (rc) {
+			/*
+			 * Do not return -EEXIST to the caller, or the system
+			 * will not boot.
+			 */
+			if (rc != -EEXIST)
+				goto out;
+			/* But free memory to avoid memory leak. */
+			kfree(ft);
+			kfree(name);
+			kfree(otype);
+		}
 	}
 	hash_eval(p->filename_trans, "filenametr");
 	return 0;
@@ -3249,10 +3261,10 @@ static int filename_write_helper(void *key, void *data, void *ptr)
 	if (rc)
 		return rc;
 
-	buf[0] = ft->stype;
-	buf[1] = ft->ttype;
-	buf[2] = ft->tclass;
-	buf[3] = otype->otype;
+	buf[0] = cpu_to_le32(ft->stype);
+	buf[1] = cpu_to_le32(ft->ttype);
+	buf[2] = cpu_to_le32(ft->tclass);
+	buf[3] = cpu_to_le32(otype->otype);
 
 	rc = put_entry(buf, sizeof(u32), 4, fp);
 	if (rc)
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index b4feecc..18caa16 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -1231,6 +1231,10 @@ static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
 	struct context context;
 	int rc = 0;
 
+	/* An empty security context is never valid. */
+	if (!scontext_len)
+		return -EINVAL;
+
 	if (!ss_initialized) {
 		int i;
 
diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index d030818..78504a1 100644
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -152,21 +152,13 @@ int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, struct xfrm_policy *
 	return rc;
 }
 
-/*
- * LSM hook implementation that checks and/or returns the xfrm sid for the
- * incoming packet.
- */
-
-int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
+static int selinux_xfrm_skb_sid_ingress(struct sk_buff *skb,
+					u32 *sid, int ckall)
 {
-	struct sec_path *sp;
+	struct sec_path *sp = skb->sp;
 
 	*sid = SECSID_NULL;
 
-	if (skb == NULL)
-		return 0;
-
-	sp = skb->sp;
 	if (sp) {
 		int i, sid_set = 0;
 
@@ -190,6 +182,45 @@ int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
 	return 0;
 }
 
+static u32 selinux_xfrm_skb_sid_egress(struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	struct xfrm_state *x;
+
+	if (dst == NULL)
+		return SECSID_NULL;
+	x = dst->xfrm;
+	if (x == NULL || !selinux_authorizable_xfrm(x))
+		return SECSID_NULL;
+
+	return x->security->ctx_sid;
+}
+
+/*
+ * LSM hook implementation that checks and/or returns the xfrm sid for the
+ * incoming packet.
+ */
+
+int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
+{
+	if (skb == NULL) {
+		*sid = SECSID_NULL;
+		return 0;
+	}
+	return selinux_xfrm_skb_sid_ingress(skb, sid, ckall);
+}
+
+int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid)
+{
+	int rc;
+
+	rc = selinux_xfrm_skb_sid_ingress(skb, sid, 0);
+	if (rc == 0 && *sid == SECSID_NULL)
+		*sid = selinux_xfrm_skb_sid_egress(skb);
+
+	return rc;
+}
+
 /*
  * Security blob allocation for xfrm_policy and xfrm_state
  * CTX does not have a meaningful value on input