From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>
Cc: netdev <netdev@vger.kernel.org>,
Eric Dumazet <edumazet@google.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
Neal Cardwell <ncardwell@google.com>,
Yuchung Cheng <ycheng@google.com>,
soukjin bae <soukjin.bae@samsung.com>
Subject: [PATCH net 1/2] tcp: clear icsk_backoff in tcp_write_queue_purge()
Date: Fri, 15 Feb 2019 13:36:20 -0800 [thread overview]
Message-ID: <20190215213621.183537-2-edumazet@google.com> (raw)
In-Reply-To: <20190215213621.183537-1-edumazet@google.com>
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>
---
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 2079145a3b7c5f498af429c9a8289342e4421fca..cf3c5095c10e8e7e56621beae2f93c93de184489 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2528,6 +2528,7 @@ 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)
@@ -2576,7 +2577,6 @@ 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;
--
2.21.0.rc0.258.g878e2cd30e-goog
next prev parent reply other threads:[~2019-02-15 21:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-15 21:36 [PATCH net 0/2] tcp: fix possible crash in tcp_v4_err() Eric Dumazet
2019-02-15 21:36 ` Eric Dumazet [this message]
2019-02-16 2:21 ` [PATCH net 1/2] tcp: clear icsk_backoff in tcp_write_queue_purge() Neal Cardwell
2019-02-15 21:36 ` [PATCH net 2/2] tcp: tcp_v4_err() should be more careful Eric Dumazet
2019-02-16 2:21 ` Neal Cardwell
2019-02-16 2:31 ` Soheil Hassas Yeganeh
2019-02-17 23:47 ` [PATCH net 0/2] tcp: fix possible crash in tcp_v4_err() David Miller
2019-02-18 2:20 ` Eric Dumazet
2019-02-18 19:59 ` David Miller
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