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;