From 3da812d860755925da890e8c713f2d2e2d7b1bae Mon Sep 17 00:00:00 2001
From: Hannes Frederic Sowa <hannes@stressinduktion.org>
Date: Sun, 29 Sep 2013 05:40:50 +0200
Subject: [PATCH] ipv6: gre: correct calculation of max_headroom

gre_hlen already accounts for sizeof(struct ipv6_hdr) + gre header,
so initialize max_headroom to zero. Otherwise the

	if (encap_limit >= 0) {
		max_headroom += 8;
		mtu -= 8;
	}

increments an uninitialized variable before max_headroom was reset.

Found with coverity: 728539

Cc: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
Reading git-format-patch failed