From: Jason Xing <kernelxing@xxxxxxxxxxx> [ 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@xxxxxxxxxxx> Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 7859217249124..4fb5959a7f070 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