usb: gadget: g_ether: fix frame size check for 802.1Q

Checking skb->len against ETH_FRAME_LEN assumes a 1514
ethernet frame size. With an 802.1Q VLAN header, ethernet
frame length can now be 1518. Validate frame length against that.
Signed-off-by: Ian Coolidge <iancoolidge@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/usb/gadget/u_ether.c

@@ -20,6 +20,7 @@
 #include <linux/ctype.h>
 #include <linux/etherdevice.h>
 #include <linux/ethtool.h>
+#include <linux/if_vlan.h>
 
 #include "u_ether.h"
 
@@ -295,7 +296,7 @@ static void rx_complete(struct usb_ep *ep, struct usb_request *req)
 		while (skb2) {
 			if (status < 0
 					|| ETH_HLEN > skb2->len
-					|| skb2->len > ETH_FRAME_LEN) {
+					|| skb2->len > VLAN_ETH_FRAME_LEN) {
 				dev->net->stats.rx_errors++;
 				dev->net->stats.rx_length_errors++;
 				DBG(dev, "rx length %d\n", skb2->len);