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

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:

quoted

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.

quoted

 
 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