From: Fernando Luis Vazquez Cao <fernando@xxxxxxxxxxxxx> 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ Upstream commit 6671b2240c54585d4afb5286a29f1569fe5e40a8 ] Even though only the outer vlan tag can be HW accelerated in the transmission path, in the TUN/TAP driver vlan_features mirrors hw_features, which happens to have the NETIF_F_HW_VLAN_?TAG_TX flags set. Because of this, during packet tranmisssion through a stacked vlan device dev_hard_start_xmit, (incorrectly) assuming that the vlan device supports hardware vlan acceleration, does not add the vlan header to the skb payload and the inner vlan tags are lost (vlan_tci contains the outer vlan tag when userspace reads the packet from the tap device). Signed-off-by: Fernando Luis Vazquez Cao <fernando@xxxxxxxxxxxxx> Signed-off-by: Toshiaki Makita <makita.toshiaki@xxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- drivers/net/tun.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 7c8343a4f918..10636cbd3807 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1650,7 +1650,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; dev->features = dev->hw_features; - dev->vlan_features = dev->features; + dev->vlan_features = dev->features & + ~(NETIF_F_HW_VLAN_CTAG_TX | + NETIF_F_HW_VLAN_STAG_TX); INIT_LIST_HEAD(&tun->disabled); err = tun_attach(tun, file, false); -- 1.9.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html