Index: uspace/srv/net/dhcp/dhcp.c
===================================================================
--- uspace/srv/net/dhcp/dhcp.c	(revision 3daf1979a17491817827b139853413d45023ef21)
+++ uspace/srv/net/dhcp/dhcp.c	(revision 23ce2d9b2671122cc7a4e8618a227ebbfc5b139c)
@@ -304,6 +304,7 @@
 			break;
 		case opt_dns_server:
-			if (opt_len != 4)
+			if (opt_len < 4 || opt_len % 4 != 0)
 				return EINVAL;
+			/* XXX Handle multiple DNS servers properly */
 			inet_addr_set(dhcp_uint32_decode(&msgb[i]),
 			    &offer->dns_server);