From: Kuniyuki Iwashima <kuniyu@amazon.com>
Date: Tue, 12 Jul 2022 00:15:28 +0000 (-0700)
Subject: icmp: Fix a data-race around sysctl_icmp_ratemask.
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=8d7a13654a988a8433bfbe3474f83b82c0dea6ab;p=linux.git

icmp: Fix a data-race around sysctl_icmp_ratemask.

[ Upstream commit 1ebcb25ad6fc3d50fca87350acf451b9a66dd31e ]

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

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
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>
---

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 3a36c198965d9..a5cc89506c1e4 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -290,7 +290,7 @@ static bool icmpv4_mask_allow(struct net *net, int type, int code)
 		return true;
 
 	/* Limit if icmp type is enabled in ratemask. */
-	if (!((1 << type) & net->ipv4.sysctl_icmp_ratemask))
+	if (!((1 << type) & READ_ONCE(net->ipv4.sysctl_icmp_ratemask)))
 		return true;
 
 	return false;