[PATCH 4.9 001/172] ipv6: release dst on error in ip6_dst_lookup_tail

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

------------------

From: Willem de Bruijn <willemb@google.com>

commit 00ea1ceebe0d9f2dc1cc2b7bd575a00100c27869 upstream.

If ip6_dst_lookup_tail has acquired a dst and fails the IPv4-mapped
check, release the dst before returning an error.

Fixes: ec5e3b0a1d41 ("ipv6: Inhibit IPv4-mapped src address on the wire.")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/ipv6/ip6_output.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1020,8 +1020,10 @@ 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;
+	    !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) {
+		err = -EAFNOSUPPORT;
+		goto out_err_release;
+	}
 
 	return 0;