From 3f2ac2d6511bb0652abf4d7388d65bb9ff1c641c Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 18 Jul 2022 10:26:43 -0700 Subject: [PATCH] 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: 63a6fff353d0 ("net: Avoid receiving packets with an l3mdev on unbound UDP sockets") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- include/net/udp.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/udp.h b/include/net/udp.h index 909ecf4..438b1b0 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -262,7 +262,7 @@ 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); -- 2.7.4