[PATCH 4.19 155/243] tcp: fix off-by-one bug on aborting window-probing socket

From: Greg Kroah-Hartman
Date: Wed Dec 11 2019 - 10:24:58 EST


From: Yuchung Cheng <ycheng@xxxxxxxxxx>

[ Upstream commit 3976535af0cb9fe34a55f2ffb8d7e6b39a2f8188 ]

Previously there is an off-by-one bug on determining when to abort
a stalled window-probing socket. This patch fixes that so it is
consistent with tcp_write_timeout().

Signed-off-by: Yuchung Cheng <ycheng@xxxxxxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Neal Cardwell <ncardwell@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv4/tcp_timer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index c719a41d2eba2..50b15e1c633b4 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -378,7 +378,7 @@ static void tcp_probe_timer(struct sock *sk)
return;
}

- if (icsk->icsk_probes_out > max_probes) {
+ if (icsk->icsk_probes_out >= max_probes) {
abort: tcp_write_err(sk);
} else {
/* Only send another probe if we didn't close things up. */
--
2.20.1