Re: [PATCH net] net: pppoe: check register_netdevice_notifier() error in pppoe_init()

[Qingfang Deng]

Hi,

On 2026/8/3 16:59, Minhong He wrote:
> pppoe_init() ignores register_netdevice_notifier() errors and always
> returns success after installing packet handlers, which can leave the
> module loaded without its netdev notifier registered.
>
> Check the error and unwind the packet handlers and protocol registration
> on failure.

A patch for the net tree requires a Fixes tag. As the notifier has been 
present since day 1 of the Linux git repository, you can use:

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")

> Signed-off-by: Minhong He <heminhong@xxxxxxxxxx>
> ---
>   drivers/net/ppp/pppoe.c | 11 ++++++++++-
>   1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c
> index 4a018acb5262..035795b120e0 100644
> --- a/drivers/net/ppp/pppoe.c
> +++ b/drivers/net/ppp/pppoe.c
> @@ -1278,10 +1278,19 @@ static int __init pppoe_init(void)
>   		dev_add_offload(&pppoe_packet_offload);
>   	dev_add_pack(&pppoes_ptype);
>   	dev_add_pack(&pppoed_ptype);
> -	register_netdevice_notifier(&pppoe_notifier);
> +
> +	err = register_netdevice_notifier(&pppoe_notifier);
> +	if (err)
> +		goto out_unregister_packs;


You can move the registration above the dev_add_offload(), so that the 
unwind path is cleaner.


>   
>   	return 0;
>   
> +out_unregister_packs:
> +	dev_remove_pack(&pppoed_ptype);
> +	dev_remove_pack(&pppoes_ptype);
> +	if (IS_ENABLED(CONFIG_INET))
> +		dev_remove_offload(&pppoe_packet_offload);
> +	unregister_pppox_proto(PX_PROTO_OE);
>   out_unregister_pppoe_proto:
>   	proto_unregister(&pppoe_sk_proto);
>   out_unregister_net_ops:

Best regards,

Qingfang