1 files changed, 13 insertions, 2 deletions

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index c4a1cff9c768..7d30892da064 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -323,13 +323,24 @@ static inline int __vlan_insert_inner_tag(struct sk_buff *skb,
         skb_push(skb, VLAN_HLEN);
 
         /* Move the mac header sans proto to the beginning of the new header. */
-        memmove(skb->data, skb->data + VLAN_HLEN, mac_len - ETH_TLEN);
+        if (likely(mac_len > ETH_TLEN))
+                memmove(skb->data, skb->data + VLAN_HLEN, mac_len - ETH_TLEN);
         skb->mac_header -= VLAN_HLEN;
 
         veth = (struct vlan_ethhdr *)(skb->data + mac_len - ETH_HLEN);
 
         /* first, the ethernet type */
-        veth->h_vlan_proto = vlan_proto;
+        if (likely(mac_len >= ETH_TLEN)) {
+                /* h_vlan_encapsulated_proto should already be populated, and
+                 * skb->data has space for h_vlan_proto
+                 */
+                veth->h_vlan_proto = vlan_proto;
+        } else {
+                /* h_vlan_encapsulated_proto should not be populated, and
+                 * skb->data has no space for h_vlan_proto
+                 */
+                veth->h_vlan_encapsulated_proto = skb->protocol;
+        }
 
         /* now, the TCI */
         veth->h_vlan_TCI = htons(vlan_tci);