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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 14/51] netrom: Fix a data-race around sysctl_netrom_obsolescence_count_initialiser
Date: Wed, 13 Mar 2024 13:01:35 -0400
Message-ID: <20240313170212.616443-15-sashal@kernel.org>
In-Reply-To: <20240313170212.616443-1-sashal@kernel.org>
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From: Jason Xing <kernelxing@tencent.com>

[ Upstream commit cfd9f4a740f772298308b2e6070d2c744fb5cf79 ]

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 b7be86d41d965..7859217249124 100644
--- a/net/netrom/nr_route.c
+++ b/net/netrom/nr_route.c
@@ -763,7 +763,7 @@ int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25)
 	if (ax25 != NULL) {
 		ret = nr_add_node(nr_src, "", &ax25->dest_addr, ax25->digipeat,
 				  ax25->ax25_dev->dev, 0,
-				  sysctl_netrom_obsolescence_count_initialiser);
+				  READ_ONCE(sysctl_netrom_obsolescence_count_initialiser));
 		if (ret)
 			return ret;
 	}
-- 
2.43.0