[PATCH 5.10 27/73] netrom: Fix a data-race around sysctl_netrom_routing_control

Sasha Levin
2024-03-13T16:47:12Z

From: Jason Xing <kernelxing@tencent.com>

[ Upstream commit b5dffcb8f71bdd02a4e5799985b51b12f4eeaf76 ]

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 8a5375e1dcc77..88c59bd0f7397 100644
--- a/net/netrom/nr_route.c
+++ b/net/netrom/nr_route.c
@@ -777,7 +777,7 @@ 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 */
--
2.43.0