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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Cc: Jason Xing <kernelxing@tencent.com>,
	Paolo Abeni <pabeni@redhat.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 23/51] netrom: Fix a data-race around sysctl_netrom_link_fails_count
Date: Wed, 13 Mar 2024 13:01:44 -0400
Message-ID: <20240313170212.616443-24-sashal@kernel.org>
In-Reply-To: <20240313170212.616443-1-sashal@kernel.org>
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From: Jason Xing <kernelxing@tencent.com>

[ Upstream commit bc76645ebdd01be9b9994dac39685a3d0f6f7985 ]

We need to protect the reader reading the sysctl value because the
value can be changed concurrently.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netrom/nr_route.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netrom/nr_route.c b/net/netrom/nr_route.c
index 4fb5959a7f070..37cfa880c2d05 100644
--- a/net/netrom/nr_route.c
+++ b/net/netrom/nr_route.c
@@ -725,7 +725,7 @@ void nr_link_failed(ax25_cb *ax25, int reason)
 	nr_neigh->ax25 = NULL;
 	ax25_cb_put(ax25);
 
-	if (++nr_neigh->failed < sysctl_netrom_link_fails_count) {
+	if (++nr_neigh->failed < READ_ONCE(sysctl_netrom_link_fails_count)) {
 		nr_neigh_put(nr_neigh);
 		return;
 	}
-- 
2.43.0