netrom: Fix a data-race around sysctl_netrom_transport_acknowledge_delay

[ Upstream commit 806f462ba9029d41aadf8ec93f2f99c5305deada ]

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>

diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
index be404ace98786bb6aeecae07426ea532c7184c2d..7428ea436e3185eb6bdbc956f94dc54b28576030 100644 (file)
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -455,7 +455,7 @@ static int nr_create(struct net *net, struct socket *sock, int protocol,
        nr->t1     =
                msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_timeout));
        nr->t2     =
-               msecs_to_jiffies(sysctl_netrom_transport_acknowledge_delay);
+               msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_acknowledge_delay));
        nr->n2     =
                msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_maximum_tries));
        nr->t4     =