static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
{
	struct usb_device *dev = chip->dev;
	struct usb_host_interface *alts;
	struct usb_interface_descriptor *altsd;
	struct usb_interface *iface = usb_ifnum_to_if(dev, interface);

	if (!iface) {
		dev_err(&dev->dev, "%u:%d : does not exist\n",
			ctrlif, interface);
		return -EINVAL;
	}

	alts = &iface->altsetting[0];
	altsd = get_iface_desc(alts);

	/*
	 * Android with both accessory and audio interfaces enabled gets the
	 * interface numbers wrong.
	 */
	if ((chip->usb_id == USB_ID(0x18d1, 0x2d04) ||
	     chip->usb_id == USB_ID(0x18d1, 0x2d05)) &&
	    interface == 0 &&
	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
	    altsd->bInterfaceSubClass == USB_SUBCLASS_VENDOR_SPEC) {
		interface = 2;
		iface = usb_ifnum_to_if(dev, interface);
		if (!iface)
			return -EINVAL;
		alts = &iface->altsetting[0];
		altsd = get_iface_desc(alts);
	}

	if (usb_interface_claimed(iface)) {
		dev_dbg(&dev->dev, "%d:%d: skipping, already claimed\n",
			ctrlif, interface);
		return -EINVAL;
	}

	if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
	     altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
	    altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
		int err = __snd_usbmidi_create(chip->card, iface,
					     &chip->midi_list, NULL,
					     chip->usb_id);
		if (err < 0) {
			dev_err(&dev->dev,
				"%u:%d: cannot create sequencer device\n",
				ctrlif, interface);
			return -EINVAL;
		}
		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);

		return 0;
	}

	if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
	     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
	    altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
		dev_dbg(&dev->dev,
			"%u:%d: skipping non-supported interface %d\n",
			ctrlif, interface, altsd->bInterfaceClass);
		/* skip non-supported classes */
		return -EINVAL;
	}

	if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
		dev_err(&dev->dev, "low speed audio streaming not supported\n");
		return -EINVAL;
	}

	if (! snd_usb_parse_audio_interface(chip, interface)) {
		usb_set_interface(dev, interface, 0); /* reset the current interface */
		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
	}

	return 0;
}

The product reads data past the end, or before the beginning, of the intended buffer.