Commit 706c6202 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by David S. Miller
Browse files

tcp: Fix a data-race around sysctl_tcp_frto. 



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

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 36eeee75

net/ipv4/tcp_input.c

+1 −1
Original line number Diff line number Diff line
@@ -2175,7 +2175,7 @@ void tcp_enter_loss(struct sock *sk) 
	 * loss recovery is underway except recurring timeout(s) on

	 * the same SND.UNA (sec 3.2). Disable F-RTO on path MTU probing

	 */

	tp->frto = net->ipv4.sysctl_tcp_frto &&

	tp->frto = READ_ONCE(net->ipv4.sysctl_tcp_frto) &&

		   (new_recovery || icsk->icsk_retransmits) &&

		   !inet_csk(sk)->icsk_mtup.probe_size;

}