Index: /trunk/src/VBox/Devices/Network/slirp/bootp.c
===================================================================
--- /trunk/src/VBox/Devices/Network/slirp/bootp.c	(revision 83579)
+++ /trunk/src/VBox/Devices/Network/slirp/bootp.c	(revision 83580)
@@ -388,4 +388,6 @@
 static int dhcp_send_ack(PNATState pData, struct bootp_t *bp, BOOTPClient *bc, struct mbuf *m, int fDhcpRequest)
 {
+    AssertReturn(bc != NULL, -1);
+
     int offReply = 0; /* boot_reply will fill general options and add END before sending response */
 
@@ -571,9 +573,13 @@
             break;
 
+        case REBINDING:
+            LogRel(("NAT: REBINDING state isn't impemented\n"));
+            return -1;
+
+        case SELECTING:
+            LogRel(("NAT: SELECTING state isn't impemented\n"));
+            return -1;
+
         case NONE:
-            if (dhcp_stat == REBINDING)
-                LogRel(("NAT: REBINDING state isn't impemented\n"));
-            else if (dhcp_stat == SELECTING)
-                LogRel(("NAT: SELECTING state isn't impemented\n"));
             return -1;
 
@@ -581,4 +587,7 @@
             break;
     }
+
+    if (bc == NULL)
+        return -1;
 
     LogRel(("NAT: DHCP offered IP address %RTnaipv4\n", bc->addr.s_addr));