1 files changed, 30 insertions, 4 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index c66b90f71c9b..acd32e3f1b68 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -94,6 +94,18 @@ static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 }
 #endif
 
+static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
+{
+        struct dst_entry *dst = skb_dst(skb);
+        const struct rt6_info *rt = (const struct rt6_info *)dst;
+
+        dst_hold(dst);
+        sk->sk_rx_dst = dst;
+        inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
+        if (rt->rt6i_node)
+                inet6_sk(sk)->rx_dst_cookie = rt->rt6i_node->fn_sernum;
+}
+
 static void tcp_v6_hash(struct sock *sk)
 {
         if (sk->sk_state != TCP_CLOSE) {
@@ -391,8 +403,9 @@ static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
                 tp->mtu_info = ntohl(info);
                 if (!sock_owned_by_user(sk))
                         tcp_v6_mtu_reduced(sk);
-                else
-                        set_bit(TCP_MTU_REDUCED_DEFERRED, &tp->tsq_flags);
+                else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
+                                           &tp->tsq_flags))
+                        sock_hold(sk);
                 goto out;
         }
 
@@ -1270,6 +1283,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 
         newsk->sk_gso_type = SKB_GSO_TCPV6;
         __ip6_dst_store(newsk, dst, NULL, NULL);
+        inet6_sk_rx_dst_set(newsk, skb);
 
         newtcp6sk = (struct tcp6_sock *)newsk;
         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
@@ -1447,7 +1461,17 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
                 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
 
         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
+                struct dst_entry *dst = sk->sk_rx_dst;
+
                 sock_rps_save_rxhash(sk, skb);
+                if (dst) {
+                        if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
+                            dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
+                                dst_release(dst);
+                                sk->sk_rx_dst = NULL;
+                        }
+                }
+
                 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
                         goto reset;
                 if (opt_skb)
@@ -1705,9 +1729,9 @@ static void tcp_v6_early_demux(struct sk_buff *skb)
                         struct dst_entry *dst = sk->sk_rx_dst;
                         struct inet_sock *icsk = inet_sk(sk);
                         if (dst)
-                                dst = dst_check(dst, 0);
+                                dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
                         if (dst &&
-                            icsk->rx_dst_ifindex == inet6_iif(skb))
+                            icsk->rx_dst_ifindex == skb->skb_iif)
                                 skb_dst_set_noref(skb, dst);
                 }
         }
@@ -1723,6 +1747,7 @@ static const struct inet_connection_sock_af_ops ipv6_specific = {
         .queue_xmit        = inet6_csk_xmit,
         .send_check        = tcp_v6_send_check,
         .rebuild_header    = inet6_sk_rebuild_header,
+        .sk_rx_dst_set     = inet6_sk_rx_dst_set,
         .conn_request      = tcp_v6_conn_request,
         .syn_recv_sock     = tcp_v6_syn_recv_sock,
         .net_header_len    = sizeof(struct ipv6hdr),
@@ -1754,6 +1779,7 @@ static const struct inet_connection_sock_af_ops ipv6_mapped = {
         .queue_xmit        = ip_queue_xmit,
         .send_check        = tcp_v4_send_check,
         .rebuild_header    = inet_sk_rebuild_header,
+        .sk_rx_dst_set     = inet_sk_rx_dst_set,
         .conn_request      = tcp_v6_conn_request,
         .syn_recv_sock     = tcp_v6_syn_recv_sock,
         .net_header_len    = sizeof(struct iphdr),