diff -Nur linux-2.4.20/net/ipv6/exthdrs.c linux-2.4.20.flo/net/ipv6/exthdrs.c
--- linux-2.4.20/net/ipv6/exthdrs.c	Thu Jun 21 06:00:55 2001
+++ linux-2.4.20.flo/net/ipv6/exthdrs.c	Sat Jan 25 19:34:24 2003
@@ -276,7 +276,7 @@
 
 	addr_type = ipv6_addr_type(addr);
 
-	if (addr_type&IPV6_ADDR_MULTICAST) {
+	if (addr_type&(IPV6_ADDR_MULTICAST|IPV6_ADDR_MAPPED)) {
 		kfree_skb(skb);
 		return -1;
 	}
Binary files linux-2.4.20/net/ipv6/icmp.o and linux-2.4.20.flo/net/ipv6/icmp.o differ
Binary files linux-2.4.20/net/ipv6/ip6_fib.o and linux-2.4.20.flo/net/ipv6/ip6_fib.o differ
diff -Nur linux-2.4.20/net/ipv6/ip6_input.c linux-2.4.20.flo/net/ipv6/ip6_input.c
--- linux-2.4.20/net/ipv6/ip6_input.c	Thu Apr 12 21:11:39 2001
+++ linux-2.4.20.flo/net/ipv6/ip6_input.c	Sat Jan 25 19:46:35 2003
@@ -79,6 +79,12 @@
 	if (hdr->version != 6)
 		goto err;
 
+	/* Silently drop all IPv4 mapped packets */
+	if (ipv6_addr_type(&hdr->saddr) & IPV6_ADDR_MAPPED)
+		goto err;
+	if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_MAPPED)
+		goto err;
+
 	pkt_len = ntohs(hdr->payload_len);
 
 	/* pkt_len may be zero if Jumbo payload option is present */