From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95EDDC4332F for ; Wed, 4 Jan 2023 12:43:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239260AbjADMnz (ORCPT ); Wed, 4 Jan 2023 07:43:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234944AbjADMnu (ORCPT ); Wed, 4 Jan 2023 07:43:50 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16623186CE; Wed, 4 Jan 2023 04:43:49 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B64D1B8162F; Wed, 4 Jan 2023 12:43:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9CEAC433EF; Wed, 4 Jan 2023 12:43:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672836226; bh=gKK35ke75uzbLNdiFo+ZUF6+OSLS2q0DB62aiLXqFus=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=R/7nfHYE0649pnd56Dza8eBumthC+1bmiU/8A0efpKWDA9tLXbh+bR/ew+v+6yt7S r98T4XdbtBoNszBgq6/jjGeVS955ekatwSuOgQ1l1gBR4yVM8M/H57jlug9U8wYQrd rhqBIzXzaf6LhifUtNuy4PDCFiCNOYwIwU6c2XNs= Date: Wed, 4 Jan 2023 13:43:43 +0100 From: Greg KH To: Tudor Ambarus Cc: stable@vger.kernel.org, willemdebruijn.kernel@gmail.com, mst@redhat.com, jasowang@redhat.com, edumazet@google.com, virtualization@lists.linux-foundation.org, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org, willemb@google.com, syzkaller@googlegroups.com, liuhangbin@gmail.com, linux-kernel@vger.kernel.org, joneslee@google.com Subject: Re: [PATCH 0/2] net/af_packet: Fix kernel BUG in __skb_gso_segment Message-ID: References: <20221222083545.1972489-1-tudor.ambarus@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221222083545.1972489-1-tudor.ambarus@linaro.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 22, 2022 at 10:35:43AM +0200, Tudor Ambarus wrote: > The series is intended for stable@vger.kernel.org # 5.4+ > > Syzkaller reported the following bug on linux-5.{4, 10, 15}.y: > https://syzkaller.appspot.com/bug?id=ce5575575f074c33ff80d104f5baee26f22e95f5 > > The upstream commit that introduces this bug is: > 1ed1d5921139 ("net: skip virtio_net_hdr_set_proto if protocol already set") > > Upstream fixes the bug with the following commits, one of which introduces > new support: > e9d3f80935b6 ("net/af_packet: make sure to pull mac header") > dfed913e8b55 ("net/af_packet: add VLAN support for AF_PACKET SOCK_RAW GSO") > > The additional logic and risk backported seems manageable. > > The blammed commit introduces a kernel BUG in __skb_gso_segment for > AF_PACKET SOCK_RAW GSO VLAN tagged packets. What happens is that > virtio_net_hdr_set_proto() exists early as skb->protocol is already set to > ETH_P_ALL. Then in packet_parse_headers() skb->protocol is set to > ETH_P_8021AD, but neither the network header position is adjusted, nor the > mac header is pulled. Thus when we get to validate the xmit skb and enter > skb_mac_gso_segment(), skb->mac_len has value 14, but vlan_depth gets > updated to 18 after skb_network_protocol() is called. This causes the > BUG_ON from __skb_pull(skb, vlan_depth) to be hit, as the mac header has > not been pulled yet. > > The fixes from upstream backported cleanly without conflicts. I updated > the commit message of the first patch to describe the problem encountered, > and added Cc, Fixes, Reported-by and Tested-by tags. For the second patch > I just added Cc to stable indicating the versions to be fixed, and added > my Tested and Signed-off-by tags. > > I tested the patches on linux-5.{4, 10, 15}.y. > > Eric Dumazet (1): > net/af_packet: make sure to pull mac header > > Hangbin Liu (1): > net/af_packet: add VLAN support for AF_PACKET SOCK_RAW GSO > > net/packet/af_packet.c | 20 +++++++++++++++----- > 1 file changed, 15 insertions(+), 5 deletions(-) Now queued up, thanks. greg k-h