1 files changed, 17 insertions, 6 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 42b2a6a73092..00a748d14062 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -417,10 +417,12 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
 
                 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
                         tp->mtu_info = info;
-                        if (!sock_owned_by_user(sk))
+                        if (!sock_owned_by_user(sk)) {
                                 tcp_v4_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;
                 }
 
@@ -1462,6 +1464,7 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
                 goto exit_nonewsk;
 
         newsk->sk_gso_type = SKB_GSO_TCPV4;
+        inet_sk_rx_dst_set(newsk, skb);
 
         newtp                 = tcp_sk(newsk);
         newinet               = inet_sk(newsk);
@@ -1627,9 +1630,6 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
                                 sk->sk_rx_dst = NULL;
                         }
                 }
-                if (unlikely(sk->sk_rx_dst == NULL))
-                        inet_sk_rx_dst_set(sk, skb);
-
                 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) {
                         rsk = sk;
                         goto reset;
@@ -1872,10 +1872,21 @@ static struct timewait_sock_ops tcp_timewait_sock_ops = {
         .twsk_destructor= tcp_twsk_destructor,
 };
 
+void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
+{
+        struct dst_entry *dst = skb_dst(skb);
+
+        dst_hold(dst);
+        sk->sk_rx_dst = dst;
+        inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
+}
+EXPORT_SYMBOL(inet_sk_rx_dst_set);
+
 const struct inet_connection_sock_af_ops ipv4_specific = {
         .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_v4_conn_request,
         .syn_recv_sock     = tcp_v4_syn_recv_sock,
         .net_header_len    = sizeof(struct iphdr),