From: Eric W. Biederman Date: Wed, 7 Oct 2015 21:48:33 +0000 (-0500) Subject: ipv4: Fix ip_queue_xmit to pass sk into ip_local_out_sk X-Git-Tag: v3.16.35~980 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9c84eab0508da4286b83f8d7afec5183457f20c7;p=thirdparty%2Fkernel%2Fstable.git ipv4: Fix ip_queue_xmit to pass sk into ip_local_out_sk commit 850dcc4d4dd7d5da5c1b2a780c5e649c3b649545 upstream. After a packet has been encapsulated by a tunnel we should use the tunnel sockets local multicast loopback flag to control if the encapsulated packet should be locally loopback back. Pass sk into ip_local_out_sk so that in the rare case we are dealing with a tunneled packet whose tunnel destination address is a multicast address the kernel properly decides to loopback this packet. In practice I don't think this matters as ip_queue_xmit is used by tcp, l2tp and sctp none of which I am aware of uses ip level multicasting as they are all point to point communications protocols. Let's fix this before someone uses ip_queue_xmit for a tunnel protocol that does use multicast. Fixes: aad88724c9d5 ("ipv4: add a sock pointer to dst->output() path.") Fixes: b0270e91014d ("ipv4: add a sock pointer to ip_queue_xmit()") Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller Signed-off-by: Luis Henriques --- diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index fead914b09f6c..d91fda8257bc7 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -436,7 +436,7 @@ packet_routed: skb->priority = sk->sk_priority; skb->mark = sk->sk_mark; - res = ip_local_out(skb); + res = ip_local_out_sk(sk, skb); rcu_read_unlock(); return res;