From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756652AbcEXSCR (ORCPT ); Tue, 24 May 2016 14:02:17 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:37999 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753601AbcEXR4O (ORCPT ); Tue, 24 May 2016 13:56:14 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Daniel Borkmann , "David S . Miller" , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 38/53] vlan: pull on __vlan_insert_tag error path and fix csum correction Date: Tue, 24 May 2016 10:55:08 -0700 Message-Id: <1464112523-3701-39-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1464112523-3701-1-git-send-email-kamal@canonical.com> References: <1464112523-3701-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.2.8-ckt11 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Daniel Borkmann [ Upstream commit 9241e2df4fbc648a92ea0752918e05c26255649e ] When __vlan_insert_tag() fails from skb_vlan_push() path due to the skb_cow_head(), we need to undo the __skb_push() in the error path as well that was done earlier to move skb->data pointer to mac header. Moreover, I noticed that when in the non-error path the __skb_pull() is done and the original offset to mac header was non-zero, we fixup from a wrong skb->data offset in the checksum complete processing. So the skb_postpush_rcsum() really needs to be done before __skb_pull() where skb->data still points to the mac header start and thus operates under the same conditions as in __vlan_insert_tag(). Fixes: 93515d53b133 ("net: move vlan pop/push functions into common code") Signed-off-by: Daniel Borkmann Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- net/core/skbuff.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index c412278..efcfd04 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4409,13 +4409,16 @@ int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci) __skb_push(skb, offset); err = __vlan_insert_tag(skb, skb->vlan_proto, skb_vlan_tag_get(skb)); - if (err) + if (err) { + __skb_pull(skb, offset); return err; + } + skb->protocol = skb->vlan_proto; skb->mac_len += VLAN_HLEN; - __skb_pull(skb, offset); skb_postpush_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN); + __skb_pull(skb, offset); } __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci); return 0; -- 2.7.4