[PATCH net v3] mctp: check register_netdevice_notifier() error in mctp_device_init()

[PATCH net v3] mctp: check register_netdevice_notifier() error in mctp_device_init()

[Minhong He]

mctp_device_init() handles errors from rtnl_af_register() and
rtnl_register_many(), but ignores the return value of
register_netdevice_notifier(). If notifier registration fails, init can
still return success while the module is only partially initialized.

Check the notifier registration error and fail module init early.

Fixes: 583be982d934 ("mctp: Add device handling and netlink interface")
Signed-off-by: Minhong He <heminhong@kylinos.cn>
---
v3:
- Correct Fixes tag to 583be982d934 (bug predates d51705614f66).
- No Cc:stable (unlikely init failure path; stable would also need
  d51705614f66 as a prereq on older trees).
v2: https://lore.kernel.org/netdev/20260716063534.116793-1-heminhong@kylinos.cn/
v1: https://lore.kernel.org/netdev/20260713073918.419422-1-heminhong@kylinos.cn/

 net/mctp/device.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/mctp/device.c b/net/mctp/device.c
index 2c84df674669..822120e860c8 100644
--- a/net/mctp/device.c
+++ b/net/mctp/device.c
@@ -536,7 +536,9 @@ int __init mctp_device_init(void)
 {
 	int err;
 
-	register_netdevice_notifier(&mctp_dev_nb);
+	err = register_netdevice_notifier(&mctp_dev_nb);
+	if (err)
+		return err;
 
 	err = rtnl_af_register(&mctp_af_ops);
 	if (err)
-- 
2.25.1

Re: [PATCH net v3] mctp: check register_netdevice_notifier() error in mctp_device_init()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Mon, 20 Jul 2026 15:25:18 +0800 you wrote:
> mctp_device_init() handles errors from rtnl_af_register() and
> rtnl_register_many(), but ignores the return value of
> register_netdevice_notifier(). If notifier registration fails, init can
> still return success while the module is only partially initialized.
> 
> Check the notifier registration error and fail module init early.
> 
> [...]

Here is the summary with links:
  - [net,v3] mctp: check register_netdevice_notifier() error in mctp_device_init()
    https://git.kernel.org/netdev/net/c/d9a33cadc70a

You are awesome, thank you!
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