cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses)
{
	int rc = 0;
	struct TCP_Server_Info *server = ses->server;

	if (!server->ops->need_neg || !server->ops->negotiate)
		return -ENOSYS;

	/* only send once per connect */
	if (!server->ops->need_neg(server))
		return 0;

	set_credits(server, 1);

	rc = server->ops->negotiate(xid, ses);
	if (rc == 0) {
		spin_lock(&GlobalMid_Lock);
		if (server->tcpStatus == CifsNeedNegotiate)
			server->tcpStatus = CifsGood;
		else
			rc = -EHOSTDOWN;
		spin_unlock(&GlobalMid_Lock);
	}

	return rc;
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.