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authorEric Dumazet <edumazet@google.com>2013-11-13 15:00:46 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-12-08 07:29:24 -0800
commit5e8c945dc7573ba2f28bddf51ca06b152b4bf749 (patch)
treed23eb26dbe12448feac4b63d1aeb4212f3fb107b
parent9571243bac246e21eab0301fe48b7456d8804821 (diff)
net-tcp: fix panic in tcp_fastopen_cache_set()
[ 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 <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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/ipv4/tcp_metrics.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index f6a005c485a9..306dbd9a9441 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -665,10 +665,13 @@ 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;