usb: iowarrior: replace kmalloc with kmalloc_array

A common flaw in the kernel is integer overflow during memory allocation size calculations. In an effort to reduce the frequency of these bugs, kmalloc_array was implemented, which allocates memory for an array, while at the same time detects integer overflow.

This patch replaces cases of:

kmalloc(a * b, gfp)

with:
kmalloc_array(a * b, gfp)

---
Changes in v2:
- Align GFP_KERNEL to open parenthesis.

 drivers/usb/misc/iowarrior.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

index c2991b8..ba05dd8 100644
@@ -808,8 +808,8 @@ static int iowarrior_probe(struct usb_interface *interface,
 			 dev->int_in_endpoint->bInterval);
 	/* create an internal buffer for interrupt data from the device */
 	dev->read_queue =
-	    kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
-		    GFP_KERNEL);
+	    kmalloc_array(dev->report_size + 1, MAX_INTERRUPT_BUFFER,
+			  GFP_KERNEL);
 	if (!dev->read_queue)
 		goto error;
 	/* Get the serial-number of the chip */

I am afraid there is a problem here. The driver currently is a gross violation of the DMA rules. Unfortunately your patch does not fix that.

That is on anyrhing other than x86 you cannot take the size of a report,
but you must use the size of a cache line.

Regards
Oliver