[PATCH 3.19.y-ckt 017/160] skbuff: Fix offset error in skb_reorder_vlan_header

[Kamal Mostafa]

3.19.8-ckt13 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Vlad Yasevich <vyasevich@xxxxxxxxx>

[ Upstream commit f654861569872d10dcb79d9d7ca219b316f94ff0 ]

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@xxxxxxxxx>
CC: Patrick McHardy <kaber@xxxxxxxxx>
Signed-off-by: Vladislav Yasevich <vyasevich@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
 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 060b5f7..35012ad 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4216,7 +4216,7 @@ 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;
-- 
1.9.1