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Diffstat (limited to 'net')
-rw-r--r--net/ipv6/ip6_input.c10
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);