netrom: Fix a data-race around sysctl_netrom_transport_timeout

[ Upstream commit 60a7a152abd494ed4f69098cf0f322e6bb140612 ]

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 24747163122bb1e9acbdd97269ada900d8b8acf7..685751096744834613d800bee68c53c6fdc74980 100644 (file)
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -453,7 +453,7 @@ static int nr_create(struct net *net, struct socket *sock, int protocol,
        nr_init_timers(sk);
 
        nr->t1     =
-               msecs_to_jiffies(sysctl_netrom_transport_timeout);
+               msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_timeout));
        nr->t2     =
                msecs_to_jiffies(sysctl_netrom_transport_acknowledge_delay);
        nr->n2     =