[PATCH 3.18 07/32] ipv6: Inhibit IPv4-mapped src address on the wire.

From: Greg Kroah-Hartman
Date: Mon Jun 19 2017 - 11:35:14 EST

3.18-stable review patch. If anyone has any objections, please let me know.


From: "Jonathan T. Leighton" <jtleight@xxxxxxxx>

[ 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@xxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
net/ipv6/ip6_output.c | 3 +++
1 file changed, 3 insertions(+)

--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -960,6 +960,9 @@ static int ip6_dst_lookup_tail(struct so
+ if (ipv6_addr_v4mapped(&fl6->saddr) &&
+ !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr)))

return 0;