[PATCH] net: fec: fix receive VLAN CTAG HW acceleration issue

[Fugang Duan <b38611@freescale.com>]

The current driver support receive VLAN CTAG HW acceleration feature
(NETIF_F_HW_VLAN_CTAG_RX) through software simulation. There calls the
api .skb_copy_to_linear_data_offset() to skip the VLAN tag, but there
have overlap between the two memory data point range. The patch just fix
the issue.

Reported-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Fugang Duan <B38611@freescale.com>
---
 drivers/net/ethernet/freescale/fec_main.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 9bb6220..c9b1dbb 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1475,12 +1475,14 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
 			/* Push and remove the vlan tag */
 			struct vlan_hdr *vlan_header =
 					(struct vlan_hdr *) (data + ETH_HLEN);
+			unsigned char eth_hdr[12];
 			vlan_tag = ntohs(vlan_header->h_vlan_TCI);
 
 			vlan_packet_rcvd = true;
 
+			memcpy(eth_hdr, data, 2 * ETH_ALEN);
 			skb_copy_to_linear_data_offset(skb, VLAN_HLEN,
-						       data, (2 * ETH_ALEN));
+						       eth_hdr, (2 * ETH_ALEN));
 			skb_pull(skb, VLAN_HLEN);
 		}
 
-- 
1.7.8