netdev - Re: [PATCH V3] usbnet: Prevents free active kevent

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Message-ID: <20251021183252.2eb25aac@kernel.org>
Date: Tue, 21 Oct 2025 18:32:52 -0700
From: Jakub Kicinski <kuba@...nel.org>
To: Lizhi Xu <lizhi.xu@...driver.com>
Cc: <samsun1006219@...il.com>, <ahmed.zaki@...el.com>,
 <aleksander.lobakin@...el.com>, <davem@...emloft.net>,
 <edumazet@...gle.com>, <horms@...nel.org>, <kuniyu@...zon.com>,
 <linux-kernel@...r.kernel.org>, <netdev@...r.kernel.org>,
 <pabeni@...hat.com>, <sdf@...ichev.me>, <syzkaller-bugs@...glegroups.com>,
 <syzkaller@...glegroups.com>
Subject: Re: [PATCH V3] usbnet: Prevents free active kevent

On Sat, 18 Oct 2025 22:49:40 +0800 Lizhi Xu wrote:
> --- a/drivers/net/usb/usbnet.c
> +++ b/drivers/net/usb/usbnet.c
> @@ -1672,6 +1672,9 @@ void usbnet_disconnect (struct usb_interface *intf)
>  	usb_free_urb(dev->interrupt);
>  	kfree(dev->padding_pkt);
>  
> +	cancel_work_sync(&dev->kevent);
> +	timer_delete_sync(&dev->delay);
> +
>  	free_netdev(net);

Is this the best spot to place the cancel?
I think it may be better right after unregister_netdev().
I haven't analyze this driver too closely but for example since
kevent may call the sub-driver having it running after we already
called dev->driver_info->unbind() seems risky.
-- 
pw-bot: cr