static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf)
{
	int err;

	if (dev->have_langid)
		return 0;

	if (dev->string_langid < 0)
		return -EPIPE;

	err = usb_string_sub(dev, 0, 0, tbuf);

	/* If the string was reported but is malformed, default to english
	 * (0x0409) */
	if (err == -ENODATA || (err > 0 && err < 4)) {
		dev->string_langid = 0x0409;
		dev->have_langid = 1;
		dev_err(&dev->dev,
			"language id specifier not provided by device, defaulting to English\n");
		return 0;
	}

	/* In case of all other errors, we assume the device is not able to
	 * deal with strings at all. Set string_langid to -1 in order to
	 * prevent any string to be retrieved from the device */
	if (err < 0) {
		dev_err(&dev->dev, "string descriptor 0 read error: %d\n",
					err);
		dev->string_langid = -1;
		return -EPIPE;
	}

	/* always use the first langid listed */
	dev->string_langid = tbuf[2] | (tbuf[3] << 8);
	dev->have_langid = 1;
	dev_dbg(&dev->dev, "default language 0x%04x\n",
				dev->string_langid);
	return 0;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.