Re: KASAN: use-after-free Read in hiddev_release

* Re: KASAN: use-after-free Read in hiddev_release
       [not found] <20190805081212.3144-1-hdanton@sina.com>
@ 2019-08-05 12:24 ` Jiri Kosina
  0 siblings, 0 replies; 3+ messages in thread
From: Jiri Kosina @ 2019-08-05 12:24 UTC (permalink / raw)
  To: Hillf Danton
  Cc: syzbot, andreyknvl, benjamin.tissoires, linux-input,
	linux-kernel, linux-usb, syzkaller-bugs

On Mon, 5 Aug 2019, Hillf Danton wrote:

> 1, no dev no open.
> 
> --- a/drivers/hid/usbhid/hiddev.c
> +++ b/drivers/hid/usbhid/hiddev.c
> @@ -284,6 +284,10 @@ static int hiddev_open(struct inode *ino
>  	spin_unlock_irq(&list->hiddev->list_lock);
>  
>  	mutex_lock(&hiddev->existancelock);
> +	if (!list->hiddev->exist) {
> +		res = -ENODEV;
> +		goto bail_unlock;
> +	}
>  	if (!list->hiddev->open++)
>  		if (list->hiddev->exist) {
>  			struct hid_device *hid = hiddev->hid;
> --
> 
> 2, list_del before vfree.
> 
> --- a/drivers/hid/usbhid/hiddev.c
> +++ b/drivers/hid/usbhid/hiddev.c
> @@ -300,6 +304,9 @@ bail_normal_power:
>  	hid_hw_power(hid, PM_HINT_NORMAL);
>  bail_unlock:
>  	mutex_unlock(&hiddev->existancelock);
> +	spin_lock_irq(&list->hiddev->list_lock);
> +	list_del(&list->node);
> +	spin_unlock_irq(&list->hiddev->list_lock);
>  bail:
>  	file->private_data = NULL;
>  	vfree(list);

Hilf,

both patches look good to me. Could you please resend them properly so 
that I could apply them? Thanks,

-- 
Jiri Kosina
SUSE Labs

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