From: Kuniyuki Iwashima Date: Wed, 13 Jul 2022 20:52:04 +0000 (-0700) Subject: tcp: Fix a data-race around sysctl_tcp_probe_threshold. X-Git-Tag: microblaze-v6.1~271^2~29^2~1 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=92c0aa4175474483d6cf373314343d4e624e882a;p=linux-2.6-microblaze.git tcp: Fix a data-race around sysctl_tcp_probe_threshold. While reading sysctl_tcp_probe_threshold, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 6b58e0a5f32d ("ipv4: Use binary search to choose tcp PMTU probe_size") 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 7130b405da21..aa757c74dad4 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2367,7 +2367,7 @@ static int tcp_mtu_probe(struct sock *sk) * probing process by not resetting search range to its orignal. */ if (probe_size > tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_high) || - interval < net->ipv4.sysctl_tcp_probe_threshold) { + interval < READ_ONCE(net->ipv4.sysctl_tcp_probe_threshold)) { /* Check whether enough time has elaplased for * another round of probing. */