[PATCH RT 2/6] tcp: force a dst refcount when prequeue packet

From: Steven Rostedt
Date: Fri May 03 2013 - 21:00:49 EST


From: Eric Dumazet <edumazet@xxxxxxxxxx>

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

Cc: stable-rt@xxxxxxxxxxxxxxx
Reported-by: Mike Galbraith <bitbucket@xxxxxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
include/net/tcp.h | 1 +
1 file changed, 1 insertion(+)

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 0768715..fe46019 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -931,6 +931,7 @@ 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) {
--
1.7.10.4


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