diff options
| author | Yuchung Cheng <ycheng@google.com> | 2018-12-05 14:38:38 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-17 09:28:47 +0100 |
| commit | 6293016fbd9ba1b5ecc7d1afe67fb359d4c05512 (patch) | |
| tree | eac1f2c713e0d0e7d78444472c06407ff64c9644 | |
| parent | 5567e5fefaa904d051ce03a330183125f92d2d37 (diff) | |
tcp: fix NULL ref in tail loss probe
[ Upstream commit b2b7af861122a0c0f6260155c29a1b2e594cd5b5 ]
TCP loss probe timer may fire when the retranmission queue is empty but
has a non-zero tp->packets_out counter. tcp_send_loss_probe will call
tcp_rearm_rto which triggers NULL pointer reference by fetching the
retranmission queue head in its sub-routines.
Add a more detailed warning to help catch the root cause of the inflight
accounting inconsistency.
Reported-by: Rafael Tinoco <rafael.tinoco@linaro.org>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv4/tcp_output.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 12cd64382768..1b31b0a1c7fa 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2476,14 +2476,18 @@ void tcp_send_loss_probe(struct sock *sk) skb = tcp_write_queue_tail(sk); } + if (unlikely(!skb)) { + WARN_ONCE(tp->packets_out, + "invalid inflight: %u state %u cwnd %u mss %d\n", + tp->packets_out, sk->sk_state, tp->snd_cwnd, mss); + inet_csk(sk)->icsk_pending = 0; + return; + } + /* At most one outstanding TLP retransmission. */ if (tp->tlp_high_seq) goto rearm_timer; - /* Retransmit last segment. */ - if (WARN_ON(!skb)) - goto rearm_timer; - if (skb_still_in_host_queue(sk, skb)) goto rearm_timer; |