Commit 22396941 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by David S. Miller
Browse files

tcp: Fix a data-race around sysctl_tcp_comp_sack_slack_ns. 



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

Fixes: a70437cc ("tcp: add hrtimer slack to sack compression")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4866b2b0

net/ipv4/tcp_input.c

+1 −1
Original line number Diff line number Diff line
@@ -5547,7 +5547,7 @@ static void __tcp_ack_snd_check(struct sock *sk, int ofo_possible) 
		      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);

}