 int usb_cypress_load_firmware(struct usb_device *udev, const struct firmware *fw, int type)
 {
 	struct hexline *hx;
	u8 *buf;
	int ret, pos = 0;
	u16 cpu_cs_register = cypress[type].cpu_cs_register;
 
	buf = kmalloc(sizeof(*hx), GFP_KERNEL);
	if (!buf)
 		return -ENOMEM;
	hx = (struct hexline *)buf;
 
 	/* stop the CPU */
	buf[0] = 1;
	if (usb_cypress_writemem(udev, cpu_cs_register, buf, 1) != 1)
 		err("could not stop the USB controller CPU.");
 
 	while ((ret = dvb_usb_get_hexline(fw, hx, &pos)) > 0) {
		deb_fw("writing to address 0x%04x (buffer: 0x%02x %02x)\n", hx->addr, hx->len, hx->chk);
		ret = usb_cypress_writemem(udev, hx->addr, hx->data, hx->len);

		if (ret != hx->len) {
			err("error while transferring firmware (transferred size: %d, block size: %d)",
				ret, hx->len);
			ret = -EINVAL;
			break;
		}
 	}
 	if (ret < 0) {
 		err("firmware download failed at %d with %d",pos,ret);
		kfree(buf);
 		return ret;
 	}
 
 	if (ret == 0) {
 		/* restart the CPU */
		buf[0] = 0;
		if (usb_cypress_writemem(udev, cpu_cs_register, buf, 1) != 1) {
 			err("could not restart the USB controller CPU.");
 			ret = -EINVAL;
 		}
 	} else
 		ret = -EIO;
 
	kfree(buf);
 
 	return ret;
 }

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.