[PATCH] phonet: check register_netdevice_notifier() error in phonet_device_init()

[PATCH] phonet: check register_netdevice_notifier() error in phonet_device_init()

[Minhong He]

phonet_device_init() registers a netdevice notifier before calling
phonet_netlink_register(), but does not check whether notifier
registration succeeded. On failure, netlink setup still proceeds and
init may return success without the notifier in place.

Check the notifier registration error and unwind through
phonet_device_exit() on failure.

Signed-off-by: Minhong He <heminhong@kylinos.cn>
---
 net/phonet/pn_dev.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/phonet/pn_dev.c b/net/phonet/pn_dev.c
index ad44831d6745..0445f7ef0320 100644
--- a/net/phonet/pn_dev.c
+++ b/net/phonet/pn_dev.c
@@ -356,7 +356,11 @@ int __init phonet_device_init(void)
 
 	proc_create_net("pnresource", 0, init_net.proc_net, &pn_res_seq_ops,
 			sizeof(struct seq_net_private));
-	register_netdevice_notifier(&phonet_device_notifier);
+	err = register_netdevice_notifier(&phonet_device_notifier);
+	if (err) {
+		phonet_device_exit();
+		return err;
+	}
 	err = phonet_netlink_register();
 	if (err)
 		phonet_device_exit();
-- 
2.25.1

Re: [PATCH] phonet: check register_netdevice_notifier() error in phonet_device_init()

[Rémi Denis-Courmont]

Le maanantaina 13. heinäkuuta 2026, 10.52.12 Itä-Euroopan kesäaika Minhong He 
a écrit :
> phonet_device_init() registers a netdevice notifier before calling
> phonet_netlink_register(), but does not check whether notifier
> registration succeeded. On failure, netlink setup still proceeds and
> init may return success without the notifier in place.

> Check the notifier registration error and unwind through
> phonet_device_exit() on failure.

That will unregister a notifier that is not registered. While I believe that 
would fail safe, I am not sure if that is really considered proper by 
contemporary kernel coding standards.

-- 
Rémi Denis-Courmont
https://www.remlab.net/