static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
{
	struct port_buffer *buf;
	unsigned int nr_added_bufs;
	int ret;

	nr_added_bufs = 0;
	do {
		buf = alloc_buf(vq, PAGE_SIZE, 0);
		if (!buf)
			break;

		spin_lock_irq(lock);
		ret = add_inbuf(vq, buf);
		if (ret < 0) {
			spin_unlock_irq(lock);
			free_buf(buf, true);
			break;
		}
		nr_added_bufs++;
		spin_unlock_irq(lock);
	} while (ret > 0);

	return nr_added_bufs;
}

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.