1 files changed, 42 insertions, 37 deletions

diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c
index 9978d01ba0ba..aa821cb639e5 100644
--- a/net/l2tp/l2tp_ip6.c
+++ b/net/l2tp/l2tp_ip6.c
@@ -72,8 +72,9 @@ static struct sock *__l2tp_ip6_bind_lookup(struct net *net,
 
 		if ((l2tp->conn_id == tunnel_id) &&
 		    net_eq(sock_net(sk), net) &&
-		    !(addr && ipv6_addr_equal(addr, laddr)) &&
-		    !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
+		    (!addr || ipv6_addr_equal(addr, laddr)) &&
+		    (!sk->sk_bound_dev_if || !dif ||
+		     sk->sk_bound_dev_if == dif))
 			goto found;
 	}
 
@@ -196,16 +197,17 @@ pass_up:
 		struct ipv6hdr *iph = ipv6_hdr(skb);
 
 		read_lock_bh(&l2tp_ip6_lock);
-		sk = __l2tp_ip6_bind_lookup(net, &iph->daddr,
-					    0, tunnel_id);
+		sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, inet6_iif(skb),
+					    tunnel_id);
+		if (!sk) {
+			read_unlock_bh(&l2tp_ip6_lock);
+			goto discard;
+		}
+
+		sock_hold(sk);
 		read_unlock_bh(&l2tp_ip6_lock);
 	}
 
-	if (sk == NULL)
-		goto discard;
-
-	sock_hold(sk);
-
 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
 		goto discard_put;
 
@@ -266,6 +268,7 @@ static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr;
 	struct net *net = sock_net(sk);
 	__be32 v4addr = 0;
+	int bound_dev_if;
 	int addr_type;
 	int err;
 
@@ -284,13 +287,6 @@ static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	if (addr_type & IPV6_ADDR_MULTICAST)
 		return -EADDRNOTAVAIL;
 
-	err = -EADDRINUSE;
-	read_lock_bh(&l2tp_ip6_lock);
-	if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr,
-				   sk->sk_bound_dev_if, addr->l2tp_conn_id))
-		goto out_in_use;
-	read_unlock_bh(&l2tp_ip6_lock);
-
 	lock_sock(sk);
 
 	err = -EINVAL;
@@ -300,28 +296,25 @@ static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	if (sk->sk_state != TCP_CLOSE)
 		goto out_unlock;
 
+	bound_dev_if = sk->sk_bound_dev_if;
+
 	/* Check if the address belongs to the host. */
 	rcu_read_lock();
 	if (addr_type != IPV6_ADDR_ANY) {
 		struct net_device *dev = NULL;
 
 		if (addr_type & IPV6_ADDR_LINKLOCAL) {
-			if (addr_len >= sizeof(struct sockaddr_in6) &&
-			    addr->l2tp_scope_id) {
-				/* Override any existing binding, if another
-				 * one is supplied by user.
-				 */
-				sk->sk_bound_dev_if = addr->l2tp_scope_id;
-			}
+			if (addr->l2tp_scope_id)
+				bound_dev_if = addr->l2tp_scope_id;
 
 			/* Binding to link-local address requires an
-			   interface */
-			if (!sk->sk_bound_dev_if)
+			 * interface.
+			 */
+			if (!bound_dev_if)
 				goto out_unlock_rcu;
 
 			err = -ENODEV;
-			dev = dev_get_by_index_rcu(sock_net(sk),
-						   sk->sk_bound_dev_if);
+			dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if);
 			if (!dev)
 				goto out_unlock_rcu;
 		}
@@ -336,13 +329,22 @@ static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	}
 	rcu_read_unlock();
 
-	inet->inet_rcv_saddr = inet->inet_saddr = v4addr;
+	write_lock_bh(&l2tp_ip6_lock);
+	if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, bound_dev_if,
+				   addr->l2tp_conn_id)) {
+		write_unlock_bh(&l2tp_ip6_lock);
+		err = -EADDRINUSE;
+		goto out_unlock;
+	}
+
+	inet->inet_saddr = v4addr;
+	inet->inet_rcv_saddr = v4addr;
+	sk->sk_bound_dev_if = bound_dev_if;
 	sk->sk_v6_rcv_saddr = addr->l2tp_addr;
 	np->saddr = addr->l2tp_addr;
 
 	l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id;
 
-	write_lock_bh(&l2tp_ip6_lock);
 	sk_add_bind_node(sk, &l2tp_ip6_bind_table);
 	sk_del_node_init(sk);
 	write_unlock_bh(&l2tp_ip6_lock);
@@ -355,10 +357,7 @@ out_unlock_rcu:
 	rcu_read_unlock();
 out_unlock:
 	release_sock(sk);
-	return err;
 
-out_in_use:
-	read_unlock_bh(&l2tp_ip6_lock);
 	return err;
 }
 
@@ -371,9 +370,6 @@ static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr,
 	int	addr_type;
 	int rc;
 
-	if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
-		return -EINVAL;
-
 	if (addr_len < sizeof(*lsa))
 		return -EINVAL;
 
@@ -390,10 +386,18 @@ static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr,
 			return -EINVAL;
 	}
 
-	rc = ip6_datagram_connect(sk, uaddr, addr_len);
-
 	lock_sock(sk);
 
+	 /* Must bind first - autobinding does not work */
+	if (sock_flag(sk, SOCK_ZAPPED)) {
+		rc = -EINVAL;
+		goto out_sk;
+	}
+
+	rc = __ip6_datagram_connect(sk, uaddr, addr_len);
+	if (rc < 0)
+		goto out_sk;
+
 	l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
 
 	write_lock_bh(&l2tp_ip6_lock);
@@ -401,6 +405,7 @@ static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr,
 	sk_add_bind_node(sk, &l2tp_ip6_bind_table);
 	write_unlock_bh(&l2tp_ip6_lock);
 
+out_sk:
 	release_sock(sk);
 
 	return rc;