Commit f39b03bd authored Jul 18, 2022 by Kuniyuki Iwashima Committed by Greg Kroah-Hartman Jul 29, 2022

udp: Fix a data-race around sysctl_udp_l3mdev_accept.



[ Upstream commit 3d72bb4188c708bb16758c60822fc4dda7a95174 ]

While reading sysctl_udp_l3mdev_accept, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.

Fixes: 63a6fff3 ("net: Avoid receiving packets with an l3mdev on unbound UDP sockets")
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>

parent 6727f39e

include/net/udp.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -252,7 +252,7 @@ static inline bool udp_sk_bound_dev_eq(struct net *net, int bound_dev_if,
		int dif, int sdif)
		{
		#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
		return inet_bound_dev_eq(!!net->ipv4.sysctl_udp_l3mdev_accept,
		return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_udp_l3mdev_accept),
		bound_dev_if, dif, sdif);
		#else
		return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);