Re: [PATCH] kthread: Unpark only parked kthreads (was Re: [syzbot] [wireguard?] WARNING in kthread_unpark (2))

[Frederic Weisbecker <frederic@kernel.org>]

Le Fri, Sep 13, 2024 at 08:11:09PM +0800, Hillf Danton a écrit :
> Test Frederic's idea.
> 
> #syz test upstream master

Thanks!

> 
> --- a/kernel/kthread.c
> +++ b/kernel/kthread.c
> @@ -623,6 +623,8 @@ void kthread_unpark(struct task_struct *
>  {
>  	struct kthread *kthread = to_kthread(k);
>  
> +	if (!test_bit(KTHREAD_SHOULD_PARK, &kthread->flags))
> +		return;
>  	/*
>  	 * Newly created kthread was parked when the CPU was offline.
>  	 * The binding was lost and we need to set it again.

But are the following bits deliberate?

> --- l/drivers/input/misc/yealink.c
> +++ y/drivers/input/misc/yealink.c
> @@ -438,7 +438,7 @@ static void urb_irq_callback(struct urb
>  
>  	yealink_do_idle_tasks(yld);
>  
> -	if (!yld->shutdown) {
> +	if (!yld->shutdown && status != -EPROTO) {
>  		ret = usb_submit_urb(yld->urb_ctl, GFP_ATOMIC);
>  		if (ret && ret != -EPERM)
>  			dev_err(&yld->intf->dev,
> @@ -460,13 +460,13 @@ static void urb_ctl_callback(struct urb
>  	case CMD_KEYPRESS:
>  	case CMD_SCANCODE:
>  		/* ask for a response */
> -		if (!yld->shutdown)
> +		if (!yld->shutdown && status != -EPROTO)
>  			ret = usb_submit_urb(yld->urb_irq, GFP_ATOMIC);
>  		break;
>  	default:
>  		/* send new command */
>  		yealink_do_idle_tasks(yld);
> -		if (!yld->shutdown)
> +		if (!yld->shutdown && status != -EPROTO)
>  			ret = usb_submit_urb(yld->urb_ctl, GFP_ATOMIC);
>  		break;
>  	}
> --
>