--- server/dhcp.c	2008-01-22 12:28:24.000000000 -0500
+++ server/dhcp.c.oden	2009-07-19 08:37:18.000000000 -0400
@@ -1800,6 +1800,8 @@ void ack_lease (packet, lease, offer, wh
 				host_reference (&host, h, MDL);
 		}
 		if (!host) {
+			if (hp)
+				host_dereference (&hp, MDL);
 			find_hosts_by_haddr (&hp,
 					     packet -> raw -> htype,
 					     packet -> raw -> chaddr,