static int get_chars(u32 vtermno, char *buf, int count)
{
	struct port *port;

	/* If we've not set up the port yet, we have no input to give. */
	if (unlikely(early_put_chars))
		return 0;

	port = find_port_by_vtermno(vtermno);
	if (!port)
		return -EPIPE;

	/* If we don't have an input queue yet, we can't get input. */
	BUG_ON(!port->in_vq);

	return fill_readbuf(port, (__force char __user *)buf, count, false);
}

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.