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 X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0DC82C43381 for ; Fri, 15 Feb 2019 17:36:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE23E218D9 for ; Fri, 15 Feb 2019 17:36:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AyxssUrq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728593AbfBORgj (ORCPT ); Fri, 15 Feb 2019 12:36:39 -0500 Received: from mail-pg1-f194.google.com ([209.85.215.194]:42152 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726045AbfBORgj (ORCPT ); Fri, 15 Feb 2019 12:36:39 -0500 Received: by mail-pg1-f194.google.com with SMTP id d72so5103711pga.9 for ; Fri, 15 Feb 2019 09:36:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=RQgXZasJPYr2Ee7fVwdaM4uFa9YCkEwManeQ+CnJTFA=; b=AyxssUrqg+Q33SL8k3Y/vTkKQTKGAVMwfRPNnpMMedxWDkFPUdfx+rX3FLMip0KMVr D5o7iSsk3L2j7GFyiUP9tvKx08rByJJF1rLGtM1DKYWj/DYh1m84ly8LgOsDHhM9wT8F WN2hQ85xKokjYrRjvMlchASJ/am+YKgkiuxCM9EcGrj9x4dug/DL0vJCRVHnwATm7FHE DbYXc6CSgTVJWph0VkDy6EdfXyOBxczMdCCo8g+1XzoKGFA6eYi+mpsRJ0N6jqd8aLYf w4ua+NGQEisE/Ir70RJLBpVGfpMpCZY08Sh/vt3CI0+eQieiRhT9dUZpAQb+wB6dffee F6lQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=RQgXZasJPYr2Ee7fVwdaM4uFa9YCkEwManeQ+CnJTFA=; b=aaNcdnTX+c7LHLnfUxPJegO71o+Ae/MQRsRhuD09Tv0ViHEZUUAKNMU7IC5VS7xX31 GeMFvxxllcVkztTlarcGlhV7mdfNRKOT5MzFgbBSZlsDwK8tJD8w1yWfMEfCi96/BZ7R GRPAikqrT/G3w4Z1tv1JfwXDvYymXoTVoImihkDtldFeAgxv4MuVBHPd2H1b5ZHGCZbR 7Q+Gk2q5/k2XaWiFOA9sFfIIBnbjSjp2CxGtyGxgiWu07ykSiLX48v+A+38Xpm9xPDA4 YlPLHebvdg8uIkhcOPsR8SjUJRtcNAunOYLkrGby6KDPLCprRhhDuI3ULMpRP9gIwrdh 0+OQ== X-Gm-Message-State: AHQUAuYM/DauOjNf1ZGJFGjwSoLxWdSPa4pGNsWSw/r7Jx4arRQxLhrm y39YzgCXtyD3E0qxBRg0+tM= X-Google-Smtp-Source: AHgI3IaJYj4FTTO2y4PDatQnJZA8q3rgi35isQ6pamNYj+nFCC3neCm+weCH8jLkVRDwcn67zpIEow== X-Received: by 2002:a63:2d6:: with SMTP id 205mr10522732pgc.180.1550252198592; Fri, 15 Feb 2019 09:36:38 -0800 (PST) Received: from ?IPv6:2620:15c:2c1:200:55c7:81e6:c7d8:94b? ([2620:15c:2c1:200:55c7:81e6:c7d8:94b]) by smtp.gmail.com with ESMTPSA id z13sm9600115pgf.84.2019.02.15.09.36.36 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Feb 2019 09:36:37 -0800 (PST) Subject: Re: [PATCH net] net: validate untrusted gso packets without csum offload To: Willem de Bruijn , netdev@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, jasowang@redhat.com, maximmi@mellanox.com, Willem de Bruijn , syzbot References: <20190215171547.247018-1-willemdebruijn.kernel@gmail.com> From: Eric Dumazet Message-ID: <0116d20d-a2ea-e4b8-8aa6-a1c4d0128fc5@gmail.com> Date: Fri, 15 Feb 2019 09:36:36 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20190215171547.247018-1-willemdebruijn.kernel@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 02/15/2019 09:15 AM, Willem de Bruijn wrote: > From: Willem de Bruijn > > Syzkaller again found a path to a kernel crash through bad gso input. > By building an excessively large packet to cause an skb field to wrap. > > If VIRTIO_NET_HDR_F_NEEDS_CSUM was set this would have been dropped in > skb_partial_csum_set. > > GSO packets that do not set checksum offload are suspicious and rare. > Most callers of virtio_net_hdr_to_skb already pass them to > skb_probe_transport_header. > > Move that test forward, change it to detect parse failure and drop > packets on failure as those cleary are not one of the legitimate > VIRTIO_NET_HDR_GSO types. > > Fixes: bfd5f4a3d605 ("packet: Add GSO/csum offload support.") > Fixes: f43798c27684 ("tun: Allow GSO using virtio_net_hdr") > Reported-by: syzbot > Signed-off-by: Willem de Bruijn Reviewed-by: Eric Dumazet