[PATCH 4.9 011/108] ipv6: Inhibit IPv4-mapped src address on the wire.

Greg Kroah-Hartman
2017-06-15T18:28:03Z

From: "Jonathan T. Leighton" <jtleight@udel.edu>

[ Upstream commit ec5e3b0a1d41fbda0cc33a45bc9e54e91d9d12c7 ]

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 <jtleight@udel.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv6/ip6_output.c | 3 +++
1 file changed, 3 insertions(+)

--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1019,6 +1019,9 @@ static int ip6_dst_lookup_tail(struct ne
}
}
#endif
+ if (ipv6_addr_v4mapped(&fl6->saddr) &&
+ !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr)))
+ return -EAFNOSUPPORT;

return 0;