[PATCH net] can: isotp: check register_netdevice_notifier() error in module init

[Minhong He]

Check the return value of register_netdevice_notifier() after a successful
can_proto_register(). If notifier registration fails, unregister the CAN
protocol before returning the error.

Fixes: 8d0caedb7596 ("can: bcm/raw/isotp: use per module netdevice notifier")

Signed-off-by: Minhong He <heminhong@xxxxxxxxxx>
---
 net/can/isotp.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/net/can/isotp.c b/net/can/isotp.c
index 54becaf6898f..65e890cafd7a 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -1908,12 +1908,18 @@ static __init int isotp_module_init(void)
 	pr_info("can: isotp protocol (max_pdu_size %d)\n", max_pdu_size);
 
 	err = can_proto_register(&isotp_can_proto);
-	if (err < 0)
+	if (err < 0) {
 		pr_err("can: registration of isotp protocol failed %pe\n", ERR_PTR(err));
-	else
-		register_netdevice_notifier(&canisotp_notifier);
+		return err;
+	}
 
-	return err;
+	err = register_netdevice_notifier(&canisotp_notifier);
+	if (err) {
+		can_proto_unregister(&isotp_can_proto);
+		return err;
+	}
+
+	return 0;
 }
 
 static __exit void isotp_module_exit(void)
-- 
2.25.1