There is some codes of tun/tap module which did not check the return
value of register_netdevice_notifier. Add the check now.
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
                goto err_misc;
        }
 
-       register_netdevice_notifier(&tun_notifier_block);
+       ret = register_netdevice_notifier(&tun_notifier_block);
+       if (ret) {
+               pr_err("Can't register netdevice notifier\n");
+               goto err_notifier;
+       }
+
        return  0;
+
+err_notifier:
+       misc_deregister(&tun_miscdev);
 err_misc:
        rtnl_link_unregister(&tun_link_ops);
 err_linkops: