From 6e1a8eb4ed3f954059ffae5563710275bc63d4fa Mon Sep 17 00:00:00 2001 From: Toshiaki Makita Date: Mon, 22 Dec 2014 19:04:14 +0900 Subject: [PATCH] net: Fix stacked vlan offload features computation [ Upstream commit 796f2da81bead71ffc91ef70912cd8d1827bf756 ] When vlan tags are stacked, it is very likely that the outer tag is stored in skb->vlan_tci and skb->protocol shows the inner tag's vlan_proto. Currently netif_skb_features() first looks at skb->protocol even if there is the outer tag in vlan_tci, thus it incorrectly retrieves the protocol encapsulated by the inner vlan instead of the inner vlan protocol. This allows GSO packets to be passed to HW and they end up being corrupted. Fixes: 58e998c6d239 ("offloading: Force software GSO for multiple vlan tags.") Signed-off-by: Toshiaki Makita Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- net/core/dev.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 70876db1ade2b..5f26b64da9ac6 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2504,11 +2504,14 @@ netdev_features_t netif_skb_dev_features(struct sk_buff *skb, if (skb_shinfo(skb)->gso_segs > dev->gso_max_segs) features &= ~NETIF_F_GSO_MASK; - if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD)) { - struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data; - protocol = veh->h_vlan_encapsulated_proto; - } else if (!vlan_tx_tag_present(skb)) { - return harmonize_features(skb, dev, features); + if (!vlan_tx_tag_present(skb)) { + if (unlikely(protocol == htons(ETH_P_8021Q) || + protocol == htons(ETH_P_8021AD))) { + struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data; + protocol = veh->h_vlan_encapsulated_proto; + } else { + return harmonize_features(skb, dev, features); + } } features = netdev_intersect_features(features, -- 2.47.3