[PATCH net] batman-adv: check register_netdevice_notifier() and rtnl_link_register() errors

[Minhong He]

batadv_init() ignores errors from register_netdevice_notifier() and
rtnl_link_register(), so the module can load without those registrations
in place.

Check both return values and unwind prior initialization in reverse order
of acquisition on failure.

Signed-off-by: Minhong He <heminhong@xxxxxxxxxx>
---
 net/batman-adv/main.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index 73becb054948..e6bcaf2d14ed 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -108,8 +108,14 @@ static int __init batadv_init(void)
 	if (ret < 0)
 		goto err_init_wifi;
 
-	register_netdevice_notifier(&batadv_hard_if_notifier);
-	rtnl_link_register(&batadv_link_ops);
+	ret = register_netdevice_notifier(&batadv_hard_if_notifier);
+	if (ret < 0)
+		goto err_reg_notifier;
+
+	ret = rtnl_link_register(&batadv_link_ops);
+	if (ret < 0)
+		goto err_rtnl_link;
+
 	batadv_netlink_register();
 
 	pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
@@ -117,6 +123,10 @@ static int __init batadv_init(void)
 
 	return 0;
 
+err_rtnl_link:
+	unregister_netdevice_notifier(&batadv_hard_if_notifier);
+err_reg_notifier:
+	batadv_wifi_net_devices_deinit();
 err_init_wifi:
 	destroy_workqueue(batadv_event_workqueue);
 	batadv_event_workqueue = NULL;
-- 
2.25.1