static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
 			  loff_t *ppos)
 {
 	struct usb_yurex *dev;
	int retval = 0;
	int bytes_read = 0;
 	char in_buffer[20];
 	unsigned long flags;
 
 	dev = file->private_data;
 
 	mutex_lock(&dev->io_mutex);
 	if (!dev->interface) {		/* already disconnected */
		retval = -ENODEV;
		goto exit;
 	}
 
 	spin_lock_irqsave(&dev->lock, flags);
	bytes_read = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
 	spin_unlock_irqrestore(&dev->lock, flags);
	if (*ppos < bytes_read) {
		if (copy_to_user(buffer, in_buffer + *ppos, bytes_read - *ppos))
			retval = -EFAULT;
		else {
			retval = bytes_read - *ppos;
			*ppos += bytes_read;
		}
	}
exit:
 	mutex_unlock(&dev->io_mutex);
	return retval;
 }

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.