From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755329AbcEQBWJ (ORCPT ); Mon, 16 May 2016 21:22:09 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34287 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755110AbcEQBWD (ORCPT ); Mon, 16 May 2016 21:22:03 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Borkmann , Jiri Pirko , "David S. Miller" Subject: [PATCH 4.5 010/101] vlan: pull on __vlan_insert_tag error path and fix csum correction Date: Mon, 16 May 2016 18:20:15 -0700 Message-Id: <20160517011506.732985179@linuxfoundation.org> X-Mailer: git-send-email 2.8.2 In-Reply-To: <20160517011506.359924439@linuxfoundation.org> References: <20160517011506.359924439@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.5-stable review patch. If anyone has any objections, please let me know. ------------------ 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: Greg Kroah-Hartman --- net/core/skbuff.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4427,13 +4427,16 @@ int skb_vlan_push(struct sk_buff *skb, _ __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;