From: Jonathan T. Leighton <jtleight@udel.edu>
Date: Wed, 24 May 2017 01:53:34 +0000 (-0400)
Subject: ipv6: Inhibit IPv4-mapped src address on the wire.
X-Git-Tag: C0P2-H0.0--20200415~8657
X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=cb351da6f2badf45d87cf0d21826d81a77f5e433;p=linux.git

ipv6: Inhibit IPv4-mapped src address on the wire.


[ 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>
---

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 1ac3cea49171..3ab32ac57ccd 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1019,6 +1019,9 @@ 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;