tcp: Fix a data-race around sysctl_tcp_thin_linear_timeouts.

[ Upstream commit 7c6f2a86ca590d5187a073d987e9599985fb1c7c ]

While reading sysctl_tcp_thin_linear_timeouts, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its reader.

Fixes: 36e31b0af5 ("net: TCP thin linear timeouts")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Kuniyuki Iwashima
2022-07-18 10:26:47 -07:00
committed by Greg Kroah-Hartman
parent d8781f7cd0
commit cc133e4f4b

View File

@@ -574,7 +574,7 @@ out_reset_timer:
* linear-timeout retransmissions into a black hole * linear-timeout retransmissions into a black hole
*/ */
if (sk->sk_state == TCP_ESTABLISHED && if (sk->sk_state == TCP_ESTABLISHED &&
(tp->thin_lto || net->ipv4.sysctl_tcp_thin_linear_timeouts) && (tp->thin_lto || READ_ONCE(net->ipv4.sysctl_tcp_thin_linear_timeouts)) &&
tcp_stream_is_thin(tp) && tcp_stream_is_thin(tp) &&
icsk->icsk_retransmits <= TCP_THIN_LINEAR_RETRIES) { icsk->icsk_retransmits <= TCP_THIN_LINEAR_RETRIES) {
icsk->icsk_backoff = 0; icsk->icsk_backoff = 0;