From: Kuniyuki Iwashima Date: Wed, 20 Jul 2022 16:50:22 +0000 (-0700) Subject: tcp: Fix a data-race around sysctl_tcp_min_tso_segs. X-Git-Tag: v5.10.135~40 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f47e7e5b49e3f14a7dff5c1085f7a9e6f5a18b7b;p=users%2Fdwmw2%2Flinux.git 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 1a144c38039c1..657b0a4d93599 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);