[PATCH 3.16.y-ckt 096/126] skbuff: Fix offset error in skb_reorder_vlan_header

[Luis Henriques]

3.16.7-ckt22 -stable review patch.  If anyone has any objections, please let me know.

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

From: Vlad Yasevich <vyasevich at gmail.com>

commit f654861569872d10dcb79d9d7ca219b316f94ff0 upstream.

skb_reorder_vlan_header is called after the vlan header has
been pulled.  As a result the offset of the begining of
the mac header has been incrased by 4 bytes (VLAN_HLEN).
When moving the mac addresses, include this incrase in
the offset calcualation so that the mac addresses are
copied correctly.

Fixes: a6e18ff1117 (vlan: Fix untag operations of stacked vlans with REORDER_HEADER off)
CC: Nicolas Dichtel <nicolas.dichtel at 6wind.com>
CC: Patrick McHardy <kaber at trash.net>
Signed-off-by: Vladislav Yasevich <vyasevich at gmail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/core/skbuff.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index d50deee76502..7e31a99e0ed9 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3996,7 +3996,7 @@ static struct sk_buff *skb_reorder_vlan_header(struct sk_buff *skb)
 		return NULL;
 	}
 
-	memmove(skb->data - ETH_HLEN, skb->data - skb->mac_len,
+	memmove(skb->data - ETH_HLEN, skb->data - skb->mac_len - VLAN_HLEN,
 		2 * ETH_ALEN);
 	skb->mac_header += VLAN_HLEN;
 	return skb;