This is a note to let you know that I've just added the patch titled tcp: Fix a data-race around sysctl_tcp_min_tso_segs. to the 5.10-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_min_tso_segs.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f1b5c1814939520d2fb691068248e2f6b8b2abfb Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> Date: Wed Jul 20 09:50:22 2022 -0700 tcp: Fix a data-race around sysctl_tcp_min_tso_segs. [ Upstream commit e0bb4ab9dfddd872622239f49fb2bd403b70853b ] While reading sysctl_tcp_min_tso_segs, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 95bd09eb2750 ("tcp: TSO packets automatic sizing") 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 1a144c38039c..657b0a4d9359 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1984,7 +1984,7 @@ static u32 tcp_tso_segs(struct sock *sk, unsigned int mss_now) min_tso = ca_ops->min_tso_segs ? ca_ops->min_tso_segs(sk) : - sock_net(sk)->ipv4.sysctl_tcp_min_tso_segs; + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_min_tso_segs); tso_segs = tcp_tso_autosize(sk, mss_now, min_tso); return min_t(u32, tso_segs, sk->sk_gso_max_segs);