l2tp: ensure sk->dst is still valid
Florian Westphal [Fri, 25 Nov 2011 06:47:16 +0000 (06:47 +0000)]
When using l2tp over ipsec, the tunnel will hang when rekeying
occurs. Reason is that the transformer bundle attached to the dst entry
is now in STATE_DEAD and thus xfrm_output_one() drops all packets
(XfrmOutStateExpired increases).

Fix this by calling __sk_dst_check (which drops the stale dst
if xfrm dst->check callback finds that the bundle is no longer valid).

Cc: James Chapman <jchapman@katalix.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/l2tp/l2tp_core.c

index cf0f308..89ff8c6 100644 (file)
@@ -1072,7 +1072,7 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
 
        /* Get routing info from the tunnel socket */
        skb_dst_drop(skb);
-       skb_dst_set(skb, dst_clone(__sk_dst_get(sk)));
+       skb_dst_set(skb, dst_clone(__sk_dst_check(sk, 0)));
 
        inet = inet_sk(sk);
        fl = &inet->cork.fl;