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=-9.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 4878FC433E9 for ; Mon, 8 Mar 2021 16:43:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 215EC65243 for ; Mon, 8 Mar 2021 16:43:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230301AbhCHQm5 (ORCPT ); Mon, 8 Mar 2021 11:42:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57726 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230165AbhCHQmw (ORCPT ); Mon, 8 Mar 2021 11:42:52 -0500 Received: from mail-io1-xd36.google.com (mail-io1-xd36.google.com [IPv6:2607:f8b0:4864:20::d36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35FDFC06174A; Mon, 8 Mar 2021 08:42:52 -0800 (PST) Received: by mail-io1-xd36.google.com with SMTP id i8so10607175iog.7; Mon, 08 Mar 2021 08:42:52 -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=BNlx4YPfM1nidlUove0a2nwdF4iPwX2FX54lO9BqECo=; b=PrcHqWM7PnbSdR1uQ2JziJWlKjjLrk2YVlkPA6r/nL9C/TPD9MIerRj2HQKQ71IvB5 JZU4S05UPtRRGfcpGqJtEnZv4A7oASYA2vliIUFOdfFaoWy2tITkB2UETbyZ9QQ6EjCJ KUjWfSANCUvDkJYwX9160gXx8laQ8HA5OFt9Jcjv63VLYFq7e7Q7812gxrMeSAx9Rc2y HCRy9naWrSGM4I0ISYuLtmW5rYiX/RKy0a7rg7uJfNC5W8IkWhZ/hbIcpLkATg8bTaaJ uwcj/UHKS1bqp8Qf7+5Jddb55e5G5zDtBp/9y3nZBfCZAl3WYaW4VhQ234YZY1hBZPuw G+Kg== 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=BNlx4YPfM1nidlUove0a2nwdF4iPwX2FX54lO9BqECo=; b=kNLzruWJJepRVn7Ab6CavNZY2IxmyDii6tACNCzPSnjg+c6p0ZLuA62YSyy79+e8KO zJuOVPzRMXfrzMm5v9PO+iDIen9ieCr84F9PCN/0Kto1Htvya9R2B3aX67/Q8DOzQUGt 6bwOaWy33x8wOP9dwPvwHFbjd2kQCOISCwwMxU8temcnblSuXtZSB/kizFEpCI9YWJuE ty/gcN69hBvom0jNPs3gKHChcJBhwJZz+Zqyvymd3Fpb9GXoHkd5J1+KAe/O7trHwV0U djiIz/tk5NQ6oSYaqNc3dU9N9gSvgH3t4bSe7ttewb/YroclLFzwOoLz4X3ujccg8YoV 0Yxw== X-Gm-Message-State: AOAM5322MNDtyg3rcVBUvMykMQiNZ+YsVqgqFpOvhSIA7gYClLO0feyd BQ5ua3/SiY8oybJW7VDk+p0= X-Google-Smtp-Source: ABdhPJzIqKfSoF0sdk0JhHyfLAp1Hk3pGQs1ueevQq3Q58YZsgerxVcRu7ZhXkyZOXOPDB84Yy0r/g== X-Received: by 2002:a6b:7302:: with SMTP id e2mr19112165ioh.106.1615221771648; Mon, 08 Mar 2021 08:42:51 -0800 (PST) Received: from Davids-MacBook-Pro.local ([8.48.134.40]) by smtp.googlemail.com with ESMTPSA id k10sm6291465iop.42.2021.03.08.08.42.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 08 Mar 2021 08:42:51 -0800 (PST) Subject: Re: [PATCH v2 2/2] net: avoid infinite loop in mpls_gso_segment when mpls_hlen == 0 To: Balazs Nemeth , Willem de Bruijn Cc: Network Development , linux-kernel , "Michael S. Tsirkin" , Jason Wang , David Miller , virtualization@lists.linux-foundation.org References: <85e04e1e6367f19c8f538d145b32f5bb93788d8a.1615199056.git.bnemeth@redhat.com> <718e4f13-31a8-037c-9725-08ae3cd93ccd@gmail.com> <543ebc518aa31f04bb6a85b66f37d984ede4b031.camel@redhat.com> From: David Ahern Message-ID: Date: Mon, 8 Mar 2021 09:42:49 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <543ebc518aa31f04bb6a85b66f37d984ede4b031.camel@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/8/21 9:26 AM, Balazs Nemeth wrote: > On Mon, 2021-03-08 at 09:17 -0700, David Ahern wrote: >> On 3/8/21 9:07 AM, Willem de Bruijn wrote: >>>> diff --git a/net/mpls/mpls_gso.c b/net/mpls/mpls_gso.c >>>> index b1690149b6fa..cc1b6457fc93 100644 >>>> --- a/net/mpls/mpls_gso.c >>>> +++ b/net/mpls/mpls_gso.c >>>> @@ -27,7 +27,7 @@ static struct sk_buff *mpls_gso_segment(struct >>>> sk_buff *skb, >>>> >>>>         skb_reset_network_header(skb); >>>>         mpls_hlen = skb_inner_network_header(skb) - >>>> skb_network_header(skb); >>>> -       if (unlikely(!pskb_may_pull(skb, mpls_hlen))) >>>> +       if (unlikely(!mpls_hlen || !pskb_may_pull(skb, >>>> mpls_hlen))) >>>>                 goto out; >>> >>> Good cathc. Besides length zero, this can be more strict: a label >>> is >>> 4B, so mpls_hlen needs to be >= 4B. >>> >>> Perhaps even aligned to 4B, too, but not if there may be other >>> encap on top. >>> >>> Unfortunately there is no struct or type definition that we can use >>> a >>> sizeof instead of open coding the raw constant. >>> >> >> MPLS_HLEN can be used here. >> > > What about sizeof(struct mpls_label), like in net/ipv4/tunnel4.c? > I was thinking MPLS_HLEN because of its consistent use with skb manipulations. net/mpls code uses mpls_shim_hdr over mpls_label. Looks like the MPLS code could use some cleanups to make this consistent.