Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7e8fc428 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Greg Kroah-Hartman
Browse files

tcp: Fix data-races around sysctl_tcp_mtu_probing. 



[ Upstream commit f47d00e077e7d61baf69e46dde3210c886360207 ]

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

Fixes: 5d424d5a ("[TCP]: MTU probing")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent abf70de2

net/ipv4/tcp_output.c

+1 −1
Original line number Diff line number Diff line
@@ -1523,7 +1523,7 @@ void tcp_mtup_init(struct sock *sk) 
	struct inet_connection_sock *icsk = inet_csk(sk);

	struct net *net = sock_net(sk);



	icsk->icsk_mtup.enabled = net->ipv4.sysctl_tcp_mtu_probing > 1;

	icsk->icsk_mtup.enabled = READ_ONCE(net->ipv4.sysctl_tcp_mtu_probing) > 1;

	icsk->icsk_mtup.search_high = tp->rx_opt.mss_clamp + sizeof(struct tcphdr) +

			       icsk->icsk_af_ops->net_header_len;

	icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, net->ipv4.sysctl_tcp_base_mss);

net/ipv4/tcp_timer.c

+1 −1
Original line number Diff line number Diff line
@@ -144,7 +144,7 @@ static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk) 
	int mss;



	/* Black hole detection */

	if (!net->ipv4.sysctl_tcp_mtu_probing)

	if (!READ_ONCE(net->ipv4.sysctl_tcp_mtu_probing))

		return;



	if (!icsk->icsk_mtup.enabled) {