Subject: [PATCH net 10/12] netrom: Fix a data-race around sysctl_netrom_routing_control

From: Jason Xing <[email-masked]>
Date: Mon, 4 Mar 2024 16:20:44 +0800

From: Jason Xing <[email-masked]>

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 <[email-masked]>
---
 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 b8ddd8048f35..89e12e6eea2e 100644
--- a/net/netrom/nr_route.c
+++ b/net/netrom/nr_route.c
@@ -780,7 +780,7 @@ int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25)
 		return ret;
 	}
 
-	if (!sysctl_netrom_routing_control && ax25 != NULL)
+	if (!READ_ONCE(sysctl_netrom_routing_control) && ax25 != NULL)
 		return 0;
 
 	/* Its Time-To-Live has expired */
-- 
2.37.3