From a0464b18acc3f17ff86aa25df34c5066a21c8291 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Wed, 24 Apr 2013 18:34:55 -0700
Subject: tcp: force a dst refcount when prequeue packet

[ Upstream commit 093162553c33e9479283e107b4431378271c735d ]

Before escaping RCU protected section and adding packet into
prequeue, make sure the dst is refcounted.

Reported-by: Mike Galbraith <bitbucket@online.de>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/net/tcp.h | 1 +
 1 file changed, 1 insertion(+)

(limited to 'include')

diff --git a/include/net/tcp.h b/include/net/tcp.h
index b28a49f..4881cb6 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -902,6 +902,7 @@ static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb)
 	if (sysctl_tcp_low_latency || !tp->ucopy.task)
 		return 0;
 
+	skb_dst_force(skb);
 	__skb_queue_tail(&tp->ucopy.prequeue, skb);
 	tp->ucopy.memory += skb->truesize;
 	if (tp->ucopy.memory > sk->sk_rcvbuf) {
-- 
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