lkml.org 
[lkml]   [2019]   [Feb]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.20 17/32] tcp: clear icsk_backoff in tcp_write_queue_purge()
Date
4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit 04c03114be82194d4a4858d41dba8e286ad1787c ]

soukjin bae reported a crash in tcp_v4_err() handling
ICMP_DEST_UNREACH after tcp_write_queue_head(sk)
returned a NULL pointer.

Current logic should have prevented this :

if (seq != tp->snd_una || !icsk->icsk_retransmits ||
!icsk->icsk_backoff || fastopen)
break;

Problem is the write queue might have been purged
and icsk_backoff has not been cleared.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: soukjin bae <soukjin.bae@samsung.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/tcp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 40cbe5609663f..b102973102b9e 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2532,6 +2532,7 @@ void tcp_write_queue_purge(struct sock *sk)
sk_mem_reclaim(sk);
tcp_clear_all_retrans_hints(tcp_sk(sk));
tcp_sk(sk)->packets_out = 0;
+ inet_csk(sk)->icsk_backoff = 0;
}

int tcp_disconnect(struct sock *sk, int flags)
@@ -2580,7 +2581,6 @@ int tcp_disconnect(struct sock *sk, int flags)
tp->write_seq += tp->max_window + 2;
if (tp->write_seq == 0)
tp->write_seq = 1;
- icsk->icsk_backoff = 0;
tp->snd_cwnd = 2;
icsk->icsk_probes_out = 0;
tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
--
2.19.1


\
 
 \ /
  Last update: 2019-02-21 16:10    [W:0.153 / U:2.920 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site