Patchwork [58/78] tcp: force a dst refcount when prequeue packet

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Submitter Kamal Mostafa
Date May 28, 2013, 9:20 p.m.
Message ID <1369776027-17859-59-git-send-email-kamal@canonical.com>
Download mbox | patch
Permalink /patch/247030/
State New
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Comments

Kamal Mostafa - May 28, 2013, 9:20 p.m.
3.8.13.1 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@google.com>

commit 093162553c33e9479283e107b4431378271c735d upstream.

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>
[ luis: adjust context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 include/net/tcp.h | 1 +
 1 file changed, 1 insertion(+)

Patch

diff --git a/include/net/tcp.h b/include/net/tcp.h
index aed42c7..4da2167 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1045,6 +1045,7 @@  static inline bool tcp_prequeue(struct sock *sk, struct sk_buff *skb)
 	if (sysctl_tcp_low_latency || !tp->ucopy.task)
 		return false;
 
+	skb_dst_force(skb);
 	__skb_queue_tail(&tp->ucopy.prequeue, skb);
 	tp->ucopy.memory += skb->truesize;
 	if (tp->ucopy.memory > sk->sk_rcvbuf) {