From 34c9977b4dcaa22a86dab752284329f746925613 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Fri, 22 Jul 2022 11:22:02 -0700 Subject: [PATCH] tcp: Fix a data-race around sysctl_tcp_comp_sack_slack_ns. [ Upstream commit 22396941a7f343d704738360f9ef0e6576489d43 ] While reading sysctl_tcp_comp_sack_slack_ns, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: a70437cc09a1 ("tcp: add hrtimer slack to sack compression") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 486ca1d5b436..7b593865b4ae 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5517,7 +5517,7 @@ send_now: rtt * (NSEC_PER_USEC >> 3)/20); sock_hold(sk); hrtimer_start_range_ns(&tp->compressed_ack_timer, ns_to_ktime(delay), - sock_net(sk)->ipv4.sysctl_tcp_comp_sack_slack_ns, + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_comp_sack_slack_ns), HRTIMER_MODE_REL_PINNED_SOFT); }