dlci: acquire rtnl_lock before calling __dev_get_by_name()
Otherwise the net device returned can be freed at anytime.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/wan/dlci.c b/drivers/net/wan/dlci.c
index 147614e..1f6e053 100644
--- a/drivers/net/wan/dlci.c
+++ b/drivers/net/wan/dlci.c
@@ -385,20 +385,24 @@
struct net_device *master, *slave;
int err;
+ rtnl_lock();
+
/* validate slave device */
master = __dev_get_by_name(&init_net, dlci->devname);
- if (!master)
- return -ENODEV;
+ if (!master) {
+ err = -ENODEV;
+ goto out;
+ }
if (netif_running(master)) {
- return -EBUSY;
+ err = -EBUSY;
+ goto out;
}
dlp = netdev_priv(master);
slave = dlp->slave;
flp = netdev_priv(slave);
- rtnl_lock();
err = (*flp->deassoc)(slave, master);
if (!err) {
list_del(&dlp->list);
@@ -407,8 +411,8 @@
dev_put(slave);
}
+out:
rtnl_unlock();
-
return err;
}
