From 2dfff4b607c4b75339d3ec4adaa06dbf0a7261d9 Mon Sep 17 00:00:00 2001
From: Kuniyuki Iwashima <kuniyu@amazon.com>
Date: Wed, 6 Jul 2022 16:39:58 -0700
Subject: [PATCH] tcp: Fix a data-race around sysctl_tcp_max_orphans.
[ Upstream commit 47e6ab24e8c6e3ca10ceb5835413f401f90de4bf ]
While reading sysctl_tcp_max_orphans, it can be changed concurrently.
So, we need to add READ_ONCE() to avoid a data-race.
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>
---
net/ipv4/tcp.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f79b5a98888c1..4ac53c8f0583a 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2714,7 +2714,8 @@ static void tcp_orphan_update(struct timer_list *unused)
static bool tcp_too_many_orphans(int shift)
{
- return READ_ONCE(tcp_orphan_cache) << shift > sysctl_tcp_max_orphans;
+ return READ_ONCE(tcp_orphan_cache) << shift >
+ READ_ONCE(sysctl_tcp_max_orphans);
}
bool tcp_check_oom(struct sock *sk, int shift)
--
2.30.2