From: Kuniyuki Iwashima Date: Mon, 18 Jul 2022 17:26:45 +0000 (-0700) Subject: tcp: Fix a data-race around sysctl_tcp_early_retrans. X-Git-Tag: baikal/aarch64/sdk6.1~3518^2~3^2~8 X-Git-Url: https://git.baikalelectronics.ru/?a=commitdiff_plain;h=cadd859b45b7dee4d1694247cad2bcded6485a63;p=kernel.git tcp: Fix a data-race around sysctl_tcp_early_retrans. While reading sysctl_tcp_early_retrans, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: c3b2487f9ff9 ("tcp: early retransmit") 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 38a71e711edc9..898fcdcb7989b 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2741,7 +2741,7 @@ bool tcp_schedule_loss_probe(struct sock *sk, bool advancing_rto) if (rcu_access_pointer(tp->fastopen_rsk)) return false; - early_retrans = sock_net(sk)->ipv4.sysctl_tcp_early_retrans; + early_retrans = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_early_retrans); /* Schedule a loss probe in 2*RTT for SACK capable connections * not in loss recovery, that are either limited by cwnd or application. */