From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Dave Jones , Yuchung Cheng , Dave Jones , "David S. Miller" Subject: [PATCH 3.10 14/58] net-tcp: fix panic in tcp_fastopen_cache_set() Date: Fri, 6 Dec 2013 13:51:45 -0800 Message-Id: <20131206214846.244555713@linuxfoundation.org> In-Reply-To: <20131206214844.906193530@linuxfoundation.org> References: <20131206214844.906193530@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit dccf76ca6b626c0c4a4e09bb221adee3270ab0ef ] 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: 1fe4c481ba637 ("net-tcp: Fast Open client - cookie cache") Signed-off-by: Eric Dumazet Reported-by: Dave Jones Cc: Yuchung Cheng Acked-by: Yuchung Cheng Tested-by: Dave Jones Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_metrics.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/net/ipv4/tcp_metrics.c +++ b/net/ipv4/tcp_metrics.c @@ -665,10 +665,13 @@ void tcp_fastopen_cache_get(struct sock 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;