netrom: Fix a data-race around sysctl_netrom_transport_busy_delay

[ Upstream commit 43547d8699439a67b78d6bb39015113f7aa360fd ]

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 5a5cca18ae0c6aa459250e89f237ddda8f73d8bb..76d66eb0de2552b3e7c1918da6bb4d3c65bc269c 100644 (file)
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -459,7 +459,7 @@ static int nr_create(struct net *net, struct socket *sock, int protocol,
        nr->n2     =
                msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_maximum_tries));
        nr->t4     =
-               msecs_to_jiffies(sysctl_netrom_transport_busy_delay);
+               msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_busy_delay));
        nr->idle   =
                msecs_to_jiffies(sysctl_netrom_transport_no_activity_timeout);
        nr->window = sysctl_netrom_transport_requested_window_size;