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-Url: http://git.maquefel.me/?a=commitdiff_plain;h=e0bb4ab9dfddd872622239f49fb2bd403b70853b;p=linux.git tcp: Fix a data-race around sysctl_tcp_min_tso_segs. 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 --- diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 80c9bed733372..6e29cf391a645 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1995,7 +1995,7 @@ 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);