static int test_halt(struct usbtest_dev *tdev, int ep, struct urb *urb)
{
	int	retval;

	/* shouldn't look or act halted now */
	retval = verify_not_halted(tdev, ep, urb);
	if (retval < 0)
		return retval;

	/* set halt (protocol test only), verify it worked */
	retval = usb_control_msg(urb->dev, usb_sndctrlpipe(urb->dev, 0),
			USB_REQ_SET_FEATURE, USB_RECIP_ENDPOINT,
			USB_ENDPOINT_HALT, ep,
			NULL, 0, USB_CTRL_SET_TIMEOUT);
	if (retval < 0) {
		ERROR(tdev, "ep %02x couldn't set halt, %d\n", ep, retval);
		return retval;
	}
	retval = verify_halted(tdev, ep, urb);
	if (retval < 0) {
		int ret;

		/* clear halt anyways, else further tests will fail */
		ret = usb_clear_halt(urb->dev, urb->pipe);
		if (ret)
			ERROR(tdev, "ep %02x couldn't clear halt, %d\n",
			      ep, ret);

		return retval;
	}

	/* clear halt (tests API + protocol), verify it worked */
	retval = usb_clear_halt(urb->dev, urb->pipe);
	if (retval < 0) {
		ERROR(tdev, "ep %02x couldn't clear halt, %d\n", ep, retval);
		return retval;
	}
	retval = verify_not_halted(tdev, ep, urb);
	if (retval < 0)
		return retval;

	/* NOTE:  could also verify SET_INTERFACE clear halts ... */

	return 0;
}

The product dereferences a pointer that it expects to be valid but is NULL.