From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 27 May 2010 23:09:39 +0000 (-0700)
Subject: net: fix __neigh_event_send()
X-Git-Tag: v2.6.35-rc1~24^2~9
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a47311380e094bb201be8a818370c73c3f52122c;p=platform%2Fkernel%2Flinux-3.10.git

net: fix __neigh_event_send()

commit 7fee226ad23 (net: add a noref bit on skb dst) missed one spot
where an skb is enqueued, with a possibly not refcounted dst entry.

__neigh_event_send() inserts skb into arp_queue, so we must make sure
dst entry is refcounted, or dst entry can be freed by garbage collector
after caller exits from rcu protected section.

Reported-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index bff3790..6ba1c0e 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -934,6 +934,7 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
 				kfree_skb(buff);
 				NEIGH_CACHE_STAT_INC(neigh->tbl, unres_discards);
 			}
+			skb_dst_force(skb);
 			__skb_queue_tail(&neigh->arp_queue, skb);
 		}
 		rc = 1;