tcp: Fix a data-race around sysctl_tcp_comp_sack_delay_ns.

[ Upstream commit 4866b2b0f7 ]

While reading sysctl_tcp_comp_sack_delay_ns, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its reader.

Fixes: 6d82aa2420 ("tcp: add tcp_comp_sack_delay_ns sysctl")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Kuniyuki Iwashima 2022-07-22 11:22:01 -07:00 committed by Greg Kroah-Hartman
parent 618116a273
commit 6842c94de9

View file

@ -5512,7 +5512,8 @@ static void __tcp_ack_snd_check(struct sock *sk, int ofo_possible)
if (tp->srtt_us && tp->srtt_us < rtt)
rtt = tp->srtt_us;
delay = min_t(unsigned long, sock_net(sk)->ipv4.sysctl_tcp_comp_sack_delay_ns,
delay = min_t(unsigned long,
READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_comp_sack_delay_ns),
rtt * (NSEC_PER_USEC >> 3)/20);
sock_hold(sk);
hrtimer_start_range_ns(&tp->compressed_ack_timer, ns_to_ktime(delay),