This is a note to let you know that I've just added the patch titled
tcp: Fix a data-race around sysctl_tcp_tso_rtt_log.
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tcp-fix-a-data-race-around-sysctl_tcp_tso_rtt_log.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 32e56d364a747fcbd462c5f42fe5c67a57b23f57
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Wed Jul 20 09:50:23 2022 -0700
tcp: Fix a data-race around sysctl_tcp_tso_rtt_log.
[ Upstream commit 2455e61b85e9c99af38cd889a7101f1d48b33cb4 ]
While reading sysctl_tcp_tso_rtt_log, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: 65466904b015 ("tcp: adjust TSO packet sizes based on min_rtt")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 08466421e7e0..60c9f7f444e0 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1971,7 +1971,7 @@ static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now,
bytes = sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift);
- r = tcp_min_rtt(tcp_sk(sk)) >> sock_net(sk)->ipv4.sysctl_tcp_tso_rtt_log;
+ r = tcp_min_rtt(tcp_sk(sk)) >> READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_tso_rtt_log);
if (r < BITS_PER_TYPE(sk->sk_gso_max_size))
bytes += sk->sk_gso_max_size >> r;
