From: Jonathan T. Leighton <jtleight@udel.edu>
Date: Sun, 12 Feb 2017 22:26:06 +0000 (-0500)
Subject: ipv6: Inhibit IPv4-mapped src address on the wire.
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ec5e3b0a1d41;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

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

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>
---

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index b6a94ff0bbd0..e164684456df 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1021,6 +1021,9 @@ 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;