Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

Steffen Klassert says:

====================
pull request (net): ipsec 2017-04-19

Two fixes for af_key:

1) Add a lock to key dump to prevent a NULL pointer dereference.
   From Yuejie Shi.

2) Fix slab-out-of-bounds in parse_ipsecrequests.
   From Herbert Xu.

Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/key/af_key.c

@@ -63,8 +63,13 @@ struct pfkey_sock {
 		} u;
 		struct sk_buff	*skb;
 	} dump;
+	struct mutex dump_lock;
 };
 
+static int parse_sockaddr_pair(struct sockaddr *sa, int ext_len,
+			       xfrm_address_t *saddr, xfrm_address_t *daddr,
+			       u16 *family);
+
 static inline struct pfkey_sock *pfkey_sk(struct sock *sk)
 {
 	return (struct pfkey_sock *)sk;
@@ -139,6 +144,7 @@ static int pfkey_create(struct net *net, struct socket *sock, int protocol,
 {
 	struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);
 	struct sock *sk;
+	struct pfkey_sock *pfk;
 	int err;
 
 	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
@@ -153,6 +159,9 @@ static int pfkey_create(struct net *net, struct socket *sock, int protocol,
 	if (sk == NULL)
 		goto out;
 
+	pfk = pfkey_sk(sk);
+	mutex_init(&pfk->dump_lock);
+
 	sock->ops = &pfkey_ops;
 	sock_init_data(sock, sk);
 
@@ -281,13 +290,23 @@ static int pfkey_do_dump(struct pfkey_sock *pfk)
 	struct sadb_msg *hdr;
 	int rc;
 
+	mutex_lock(&pfk->dump_lock);
+	if (!pfk->dump.dump) {
+		rc = 0;
+		goto out;
+	}
+
 	rc = pfk->dump.dump(pfk);
-	if (rc == -ENOBUFS)
-		return 0;
+	if (rc == -ENOBUFS) {
+		rc = 0;
+		goto out;
+	}
 
 	if (pfk->dump.skb) {
-		if (!pfkey_can_dump(&pfk->sk))
-			return 0;
+		if (!pfkey_can_dump(&pfk->sk)) {
+			rc = 0;
+			goto out;
+		}
 
 		hdr = (struct sadb_msg *) pfk->dump.skb->data;
 		hdr->sadb_msg_seq = 0;
@@ -298,6 +317,9 @@ static int pfkey_do_dump(struct pfkey_sock *pfk)
 	}
 
 	pfkey_terminate_dump(pfk);
+
+out:
+	mutex_unlock(&pfk->dump_lock);
 	return rc;
 }
 
@@ -1793,19 +1815,26 @@ static int pfkey_dump(struct sock *sk, struct sk_buff *skb, const struct sadb_ms
 	struct xfrm_address_filter *filter = NULL;
 	struct pfkey_sock *pfk = pfkey_sk(sk);
 
-	if (pfk->dump.dump != NULL)
+	mutex_lock(&pfk->dump_lock);
+	if (pfk->dump.dump != NULL) {
+		mutex_unlock(&pfk->dump_lock);
 		return -EBUSY;
+	}
 
 	proto = pfkey_satype2proto(hdr->sadb_msg_satype);
-	if (proto == 0)
+	if (proto == 0) {
+		mutex_unlock(&pfk->dump_lock);
 		return -EINVAL;
+	}
 
 	if (ext_hdrs[SADB_X_EXT_FILTER - 1]) {
 		struct sadb_x_filter *xfilter = ext_hdrs[SADB_X_EXT_FILTER - 1];
 
 		filter = kmalloc(sizeof(*filter), GFP_KERNEL);
-		if (filter == NULL)
+		if (filter == NULL) {
+			mutex_unlock(&pfk->dump_lock);
 			return -ENOMEM;
+		}
 
 		memcpy(&filter->saddr, &xfilter->sadb_x_filter_saddr,
 		       sizeof(xfrm_address_t));
@@ -1821,6 +1850,7 @@ static int pfkey_dump(struct sock *sk, struct sk_buff *skb, const struct sadb_ms
 	pfk->dump.dump = pfkey_dump_sa;
 	pfk->dump.done = pfkey_dump_sa_done;
 	xfrm_state_walk_init(&pfk->dump.u.state, proto, filter);
+	mutex_unlock(&pfk->dump_lock);
 
 	return pfkey_do_dump(pfk);
 }
@@ -1913,19 +1943,14 @@ parse_ipsecrequest(struct xfrm_policy *xp, struct sadb_x_ipsecrequest *rq)
 
 	/* addresses present only in tunnel mode */
 	if (t->mode == XFRM_MODE_TUNNEL) {
-		u8 *sa = (u8 *) (rq + 1);
-		int family, socklen;
-
-		family = pfkey_sockaddr_extract((struct sockaddr *)sa,
-						&t->saddr);
-		if (!family)
-			return -EINVAL;
+		int err;
 
-		socklen = pfkey_sockaddr_len(family);
-		if (pfkey_sockaddr_extract((struct sockaddr *)(sa + socklen),
-					   &t->id.daddr) != family)
-			return -EINVAL;
-		t->encap_family = family;
+		err = parse_sockaddr_pair(
+			(struct sockaddr *)(rq + 1),
+			rq->sadb_x_ipsecrequest_len - sizeof(*rq),
+			&t->saddr, &t->id.daddr, &t->encap_family);
+		if (err)
+			return err;
 	} else
 		t->encap_family = xp->family;
 
@@ -1945,7 +1970,11 @@ parse_ipsecrequests(struct xfrm_policy *xp, struct sadb_x_policy *pol)
 	if (pol->sadb_x_policy_len * 8 < sizeof(struct sadb_x_policy))
 		return -EINVAL;
 
-	while (len >= sizeof(struct sadb_x_ipsecrequest)) {
+	while (len >= sizeof(*rq)) {
+		if (len < rq->sadb_x_ipsecrequest_len ||
+		    rq->sadb_x_ipsecrequest_len < sizeof(*rq))
+			return -EINVAL;
+
 		if ((err = parse_ipsecrequest(xp, rq)) < 0)
 			return err;
 		len -= rq->sadb_x_ipsecrequest_len;
@@ -2408,7 +2437,6 @@ static int key_pol_get_resp(struct sock *sk, struct xfrm_policy *xp, const struc
 	return err;
 }
 
-#ifdef CONFIG_NET_KEY_MIGRATE
 static int pfkey_sockaddr_pair_size(sa_family_t family)
 {
 	return PFKEY_ALIGN8(pfkey_sockaddr_len(family) * 2);
@@ -2420,7 +2448,7 @@ static int parse_sockaddr_pair(struct sockaddr *sa, int ext_len,
 {
 	int af, socklen;
 
-	if (ext_len < pfkey_sockaddr_pair_size(sa->sa_family))
+	if (ext_len < 2 || ext_len < pfkey_sockaddr_pair_size(sa->sa_family))
 		return -EINVAL;
 
 	af = pfkey_sockaddr_extract(sa, saddr);
@@ -2436,6 +2464,7 @@ static int parse_sockaddr_pair(struct sockaddr *sa, int ext_len,
 	return 0;
 }
 
+#ifdef CONFIG_NET_KEY_MIGRATE
 static int ipsecrequests_to_migrate(struct sadb_x_ipsecrequest *rq1, int len,
 				    struct xfrm_migrate *m)
 {
@@ -2443,13 +2472,14 @@ static int ipsecrequests_to_migrate(struct sadb_x_ipsecrequest *rq1, int len,
 	struct sadb_x_ipsecrequest *rq2;
 	int mode;
 
-	if (len <= sizeof(struct sadb_x_ipsecrequest) ||
-	    len < rq1->sadb_x_ipsecrequest_len)
+	if (len < sizeof(*rq1) ||
+	    len < rq1->sadb_x_ipsecrequest_len ||
+	    rq1->sadb_x_ipsecrequest_len < sizeof(*rq1))
 		return -EINVAL;
 
 	/* old endoints */
 	err = parse_sockaddr_pair((struct sockaddr *)(rq1 + 1),
-				  rq1->sadb_x_ipsecrequest_len,
+				  rq1->sadb_x_ipsecrequest_len - sizeof(*rq1),
 				  &m->old_saddr, &m->old_daddr,
 				  &m->old_family);
 	if (err)
@@ -2458,13 +2488,14 @@ static int ipsecrequests_to_migrate(struct sadb_x_ipsecrequest *rq1, int len,
 	rq2 = (struct sadb_x_ipsecrequest *)((u8 *)rq1 + rq1->sadb_x_ipsecrequest_len);
 	len -= rq1->sadb_x_ipsecrequest_len;
 
-	if (len <= sizeof(struct sadb_x_ipsecrequest) ||
-	    len < rq2->sadb_x_ipsecrequest_len)
+	if (len <= sizeof(*rq2) ||
+	    len < rq2->sadb_x_ipsecrequest_len ||
+	    rq2->sadb_x_ipsecrequest_len < sizeof(*rq2))
 		return -EINVAL;
 
 	/* new endpoints */
 	err = parse_sockaddr_pair((struct sockaddr *)(rq2 + 1),
-				  rq2->sadb_x_ipsecrequest_len,
+				  rq2->sadb_x_ipsecrequest_len - sizeof(*rq2),
 				  &m->new_saddr, &m->new_daddr,
 				  &m->new_family);
 	if (err)
@@ -2679,14 +2710,18 @@ static int pfkey_spddump(struct sock *sk, struct sk_buff *skb, const struct sadb
 {
 	struct pfkey_sock *pfk = pfkey_sk(sk);
 
-	if (pfk->dump.dump != NULL)
+	mutex_lock(&pfk->dump_lock);
+	if (pfk->dump.dump != NULL) {
+		mutex_unlock(&pfk->dump_lock);
 		return -EBUSY;
+	}
 
 	pfk->dump.msg_version = hdr->sadb_msg_version;
 	pfk->dump.msg_portid = hdr->sadb_msg_pid;
 	pfk->dump.dump = pfkey_dump_sp;
 	pfk->dump.done = pfkey_dump_sp_done;
 	xfrm_policy_walk_init(&pfk->dump.u.policy, XFRM_POLICY_TYPE_MAIN);
+	mutex_unlock(&pfk->dump_lock);
 
 	return pfkey_do_dump(pfk);
 }