From dccf8a67f30e18980d13f07006e5a536bbd1e136 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Wed, 13 Jul 2022 13:51:57 -0700 Subject: [PATCH] ip: Fix a data-race around sysctl_fwmark_reflect. [ Upstream commit 85d0b4dbd74b95cc492b1f4e34497d3f894f5d9a ] While reading sysctl_fwmark_reflect, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: e110861f8609 ("net: add a sysctl to reflect the fwmark on replies") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- include/net/ip.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/ip.h b/include/net/ip.h index c69dd114f367..a0ac57af82dc 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -379,7 +379,7 @@ void ipfrag_init(void); void ip_static_sysctl_init(void); #define IP4_REPLY_MARK(net, mark) \ - ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0) + (READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0) static inline bool ip_is_fragment(const struct iphdr *iph) { -- 2.34.1