From: Shmulik Ladkani <shmulik.ladk...@gmail.com> Date: Thu, 29 Sep 2016 12:10:40 +0300
> Generic skb_vlan_push/skb_vlan_pop functions don't properly handle the > case where the input skb data pointer does not point at the mac header: > > - They're doing push/pop, but fail to properly unwind data back to its > original location. > For example, in the skb_vlan_push case, any subsequent > 'skb_push(skb, skb->mac_len)' calls make the skb->data point 4 bytes > BEFORE start of frame, leading to bogus frames that may be transmitted. > > - They update rcsum per the added/removed 4 bytes tag. > Alas if data is originally after the vlan/eth headers, then these > bytes were already pulled out of the csum. > > OTOH calling skb_vlan_push/skb_vlan_pop with skb->data at mac_header > present no issues. > > act_vlan is the only caller to skb_vlan_*() that has skb->data pointing > at network header (upon ingress). > Other calles (ovs, bpf) already adjust skb->data at mac_header. > > This patch fixes act_vlan to point to the mac_header prior calling > skb_vlan_*() functions, as other callers do. > > Signed-off-by: Shmulik Ladkani <shmulik.ladk...@gmail.com> Applied and queued up for -stable.
