Commit 88f8598d authored Jan 16, 2019 by Yuchung Cheng Committed by David S. Miller Jan 17, 2019

tcp: exit if nothing to retransmit on RTO timeout



Previously TCP only warns if its RTO timer fires and the
retransmission queue is empty, but it'll cause null pointer
reference later on. It's better to avoid such catastrophic failure
and simply exit with a warning.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 9b420eff

net/ipv4/tcp_timer.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -443,10 +443,8 @@ void tcp_retransmit_timer(struct sock *sk)
		*/
		return;
		}
		if (!tp->packets_out)
		goto out;

		WARN_ON(tcp_rtx_queue_empty(sk));
		if (!tp->packets_out \|\| WARN_ON_ONCE(tcp_rtx_queue_empty(sk)))
		return;

		tp->tlp_high_seq = 0;