Commit 2a85388f authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by David S. Miller
Browse files

tcp: Fix a data-race around sysctl_tcp_probe_interval. 



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

Fixes: 05cbc0db ("ipv4: Create probe timer for tcp PMTU as per RFC4821")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 92c0aa41

net/ipv4/tcp_output.c

+1 −1
Original line number Diff line number Diff line
@@ -2283,7 +2283,7 @@ static inline void tcp_mtu_check_reprobe(struct sock *sk) 
	u32 interval;

	s32 delta;



	interval = net->ipv4.sysctl_tcp_probe_interval;

	interval = READ_ONCE(net->ipv4.sysctl_tcp_probe_interval);

	delta = tcp_jiffies32 - icsk->icsk_mtup.probe_timestamp;

	if (unlikely(delta >= interval * HZ)) {

		int mss = tcp_current_mss(sk);