From e7d2ef837e14a971a05f60ea08c47f3fed1a36e4 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 18 Jul 2022 10:26:46 -0700 Subject: tcp: Fix data-races around sysctl_tcp_recovery. While reading sysctl_tcp_recovery, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 4f41b1c58a32 ("tcp: use RACK to detect losses") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller --- net/ipv4/tcp_recovery.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'net/ipv4/tcp_recovery.c') diff --git a/net/ipv4/tcp_recovery.c b/net/ipv4/tcp_recovery.c index 48f30e7209f2..50abaa941387 100644 --- a/net/ipv4/tcp_recovery.c +++ b/net/ipv4/tcp_recovery.c @@ -14,7 +14,8 @@ static u32 tcp_rack_reo_wnd(const struct sock *sk) return 0; if (tp->sacked_out >= tp->reordering && - !(sock_net(sk)->ipv4.sysctl_tcp_recovery & TCP_RACK_NO_DUPTHRESH)) + !(READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_recovery) & + TCP_RACK_NO_DUPTHRESH)) return 0; } @@ -187,7 +188,8 @@ void tcp_rack_update_reo_wnd(struct sock *sk, struct rate_sample *rs) { struct tcp_sock *tp = tcp_sk(sk); - if (sock_net(sk)->ipv4.sysctl_tcp_recovery & TCP_RACK_STATIC_REO_WND || + if ((READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_recovery) & + TCP_RACK_STATIC_REO_WND) || !rs->prior_delivered) return; -- cgit v1.2.3-70-g09d2