[PATCH 1/2] ipv6: Inhibit IPv4-mapped src address on the wire.

[Jonathan T. Leighton]

This patch adds a check for the problematic case of an IPv4-mapped IPv6
source address and a destination address that is neither an IPv4-mapped
IPv6 address nor in6addr_any, and returns an appropriate error. The
check in done before returning from looking up the route.

Signed-off-by: Jonathan T. Leighton <jtlei...@udel.edu>
---
 net/ipv6/ip6_output.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index a75871c..d0f51b4 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1022,6 +1022,9 @@ static int ip6_dst_lookup_tail(struct net *net, const 
struct sock *sk,
                }
        }
 #endif
+       if (ipv6_addr_v4mapped(&fl6->saddr) &&
+           !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr)))
+               return -EAFNOSUPPORT;
 
        return 0;
 
-- 
2.7.4