Re: [PATCH] r8152: Allocate interrupt buffer as part of struct r8152

[Guenter Roeck <linux@roeck-us.net>]

On Tue, Jan 31, 2017 at 11:53:31AM -0800, Eric Dumazet wrote:
> On Tue, 2017-01-31 at 11:06 -0800, Guenter Roeck wrote:
> > When unloading the r8152 driver using the 'unbind' sysfs attribute
> > in a system with KASAN enabled, the following error message is seen
> > on a regular basis.
> 
> >  
> >  static int alloc_all_mem(struct r8152 *tp)
> > @@ -1423,10 +1420,6 @@ static int alloc_all_mem(struct r8152 *tp)
> >  	if (!tp->intr_urb)
> >  		goto err1;
> >  
> > -	tp->intr_buff = kmalloc(INTBUFSIZE, GFP_KERNEL);
> > -	if (!tp->intr_buff)
> > -		goto err1;
> > -
> >  	tp->intr_interval = (int)ep_intr->desc.bInterval;
> >  	usb_fill_int_urb(tp->intr_urb, tp->udev, usb_rcvintpipe(tp->udev, 3),
> >  			 tp->intr_buff, INTBUFSIZE, intr_callback,
> 
> This might lead to intr_buff being backed by vzalloc() instead of
> kzalloc() (check alloc_netdev_mqs())
> 
> It looks like it could cause a bug.
> 
I also strongly suspect that it just fixes the symptom, but not the root cause
of the problem.

Thanks,
Guenter