Commit dccf76ca authored Nov 13, 2013 by Eric Dumazet Committed by David S. Miller Nov 14, 2013

net-tcp: fix panic in tcp_fastopen_cache_set()



We had some reports of crashes using TCP fastopen, and Dave Jones
gave a nice stack trace pointing to the error.

Issue is that tcp_get_metrics() should not be called with a NULL dst

Fixes: 1fe4c481 ("net-tcp: Fast Open client - cookie cache")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dave Jones <davej@redhat.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Tested-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent b869ccfa

net/ipv4/tcp_metrics.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -663,10 +663,13 @@ void tcp_fastopen_cache_get(struct sock sk, u16 mss,
		void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
		struct tcp_fastopen_cookie *cookie, bool syn_lost)
		{
		struct dst_entry *dst = __sk_dst_get(sk);
		struct tcp_metrics_block *tm;

		if (!dst)
		return;
		rcu_read_lock();
		tm = tcp_get_metrics(sk, __sk_dst_get(sk), true);
		tm = tcp_get_metrics(sk, dst, true);
		if (tm) {
		struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen;