This is a note to let you know that I've just added the patch titled vlan: Fix untag operations of stacked vlans with REORDER_HEADER off to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: vlan-fix-untag-operations-of-stacked-vlans-with-reorder_header-off.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Mon Jan 18 21:17:42 PST 2016 From: Vlad Yasevich <vyasevich@xxxxxxxxx> Date: Mon, 16 Nov 2015 15:43:44 -0500 Subject: vlan: Fix untag operations of stacked vlans with REORDER_HEADER off Status: RO Content-Length: 1704 Lines: 46 From: Vlad Yasevich <vyasevich@xxxxxxxxx> [ Upstream commit a6e18ff111701b4ff6947605bfbe9594ec42a6e8 ] When we have multiple stacked vlan devices all of which have turned off REORDER_HEADER flag, the untag operation does not locate the ethernet addresses correctly for nested vlans. The reason is that in case of REORDER_HEADER flag being off, the outer vlan headers are put back and the mac_len is adjusted to account for the presense of the header. Then, the subsequent untag operation, for the next level vlan, always use VLAN_ETH_HLEN to locate the begining of the ethernet header and that ends up being a multiple of 4 bytes short of the actuall beginning of the mac header (the multiple depending on the how many vlan encapsulations ethere are). As a reslult, if there are multiple levles of vlan devices with REODER_HEADER being off, the recevied packets end up being dropped. To solve this, we use skb->mac_len as the offset. The value is always set on receive path and starts out as a ETH_HLEN. The value is also updated when the vlan header manupations occur so we know it will be correct. Signed-off-by: Vladislav Yasevich <vyasevic@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/core/skbuff.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3997,7 +3997,8 @@ static struct sk_buff *skb_reorder_vlan_ return NULL; } - memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN); + memmove(skb->data - ETH_HLEN, skb->data - skb->mac_len, + 2 * ETH_ALEN); skb->mac_header += VLAN_HLEN; return skb; } Patches currently in stable-queue which might be from vyasevich@xxxxxxxxx are queue-3.14/sctp-use-the-same-clock-as-if-sock-source-timestamps-were-on.patch queue-3.14/ipv6-sctp-clone-options-to-avoid-use-after-free.patch queue-3.14/sctp-update-the-netstamp_needed-counter-when-copying-sockets.patch queue-3.14/skbuff-fix-offset-error-in-skb_reorder_vlan_header.patch queue-3.14/sctp-translate-host-order-to-network-order-when-setting-a-hmacid.patch queue-3.14/vlan-fix-untag-operations-of-stacked-vlans-with-reorder_header-off.patch -- 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