1 files changed, 10 insertions, 0 deletions

diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 7e5df23cbe7b..3d71c7d6102c 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -223,6 +223,16 @@ static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev,
         if (ipv6_addr_is_multicast(&hdr->saddr))
                 goto err;
 
+        /* While RFC4291 is not explicit about v4mapped addresses
+         * in IPv6 headers, it seems clear linux dual-stack
+         * model can not deal properly with these.
+         * Security models could be fooled by ::ffff:127.0.0.1 for example.
+         *
+         * https://tools.ietf.org/html/draft-itojun-v6ops-v4mapped-harmful-02
+         */
+        if (ipv6_addr_v4mapped(&hdr->saddr))
+                goto err;
+
         skb->transport_header = skb->network_header + sizeof(*hdr);
         IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);