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); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 1e7acdc30732..857e4e6f751a 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5028,8 +5028,10 @@ static struct sk_buff *skb_reorder_vlan_header(struct sk_buff *skb) } mac_len = skb->data - skb_mac_header(skb); - memmove(skb_mac_header(skb) + VLAN_HLEN, skb_mac_header(skb), - mac_len - VLAN_HLEN - ETH_TLEN); + if (likely(mac_len > VLAN_HLEN + ETH_TLEN)) { + memmove(skb_mac_header(skb) + VLAN_HLEN, skb_mac_header(skb), + mac_len - VLAN_HLEN - ETH_TLEN); + } skb->mac_header += VLAN_HLEN; return skb; }