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=-3.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 6F295C9DCC3 for ; Tue, 13 Oct 2020 02:42:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 349542072C for ; Tue, 13 Oct 2020 02:42:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="KUjWt7Jz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728455AbgJMB4n (ORCPT ); Mon, 12 Oct 2020 21:56:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726168AbgJMB4n (ORCPT ); Mon, 12 Oct 2020 21:56:43 -0400 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F8E3C0613D0 for ; Mon, 12 Oct 2020 18:56:43 -0700 (PDT) Received: by mail-pl1-x62b.google.com with SMTP id 1so3952185ple.2 for ; Mon, 12 Oct 2020 18:56:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Qhtp9DcsHC+50o/dFFEBEUFxetslYLjDExV0KXZhOvU=; b=KUjWt7JzbiSYqznwkix6e2uekYJi2Oha8ca4Eo6ZvLUEAA6ipLKYQ5N0Ti8H2wxgZi 6GWlwSrk2Qkd/yxNnddUGtwGgJOXZp76Ls0ZfNs6UcFf5NbY/uhtnDE5WkqtkS0f/ZB3 hf59IQ4bCJq6doOgRthi4Smpc2xu+8YcvTlIwGByKetKWgm15mSvCbkskppC3eNKaV6O XezVH4l4JjEg4CPL6BT2D6wVtk7tB+/0MRwKCggonW05Dw4r2k7ky3fHa8OvXVoO27PO dnY3AYdUA86q2yQel85SbsUIOsJNQs1Q4j5oiFO7GwRS5T4CaKlQk3yzg8QXX3mve0JR UKVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Qhtp9DcsHC+50o/dFFEBEUFxetslYLjDExV0KXZhOvU=; b=riBf5qxMi1JY6/kO9dFE6lQHa5a3if5i+56uuFsVuoQteZldfKIB9XLerx5cgBEm7q 4s/Qm3GWYTLT1Zbi9ihvs9/lRyAby5ZluGNf+rmZGeSkXOI3G/wwhHjtp8Batb5stm+e wflK+l7C9ISn3WwMjMLvLpO6EzpLcgHEy3D7LNQHcjy/nbvhwXMAhXBFUUkiXB5LjIqG ZqOa9iaBagqBMbsaSIGQMrWaIHqhPP2SahByLXpeS7gY39uUAPAULQapkKC+87alZPHy OXk0XyHGmoh2rF0uZaAvlXs+7ruabRunJMVZ26WiTlRYiuDLvfW3TlqfiO1zUzP05zJb kVOQ== X-Gm-Message-State: AOAM533vtsi4kwBVDRXvMKa/gLs7u2otRCTQnzsUi7xHmBsZdiJGDmxb 6AX2oDZobtanPzx/nL/wpbLsxPGBqsd1Pw+1AIk= X-Google-Smtp-Source: ABdhPJwaxZ/tYZO+6w1kUxalOo1vgKDAqySQcITC5SDv5QYEB2X9bGk3RMhKFbLBXP9TcA6uzFt+BGexGf7GU8LPsAI= X-Received: by 2002:a17:902:9694:b029:d2:1b52:f46 with SMTP id n20-20020a1709029694b02900d21b520f46mr27187256plp.78.1602554202940; Mon, 12 Oct 2020 18:56:42 -0700 (PDT) MIME-Version: 1.0 References: <20201012231721.20374-1-xiyou.wangcong@gmail.com> In-Reply-To: <20201012231721.20374-1-xiyou.wangcong@gmail.com> From: Xie He Date: Mon, 12 Oct 2020 18:56:32 -0700 Message-ID: Subject: Re: [Patch net v3] ip_gre: set dev->hard_header_len and dev->needed_headroom properly To: Cong Wang Cc: Linux Kernel Network Developers , syzbot , William Tu , Willem de Bruijn Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Oct 12, 2020 at 4:17 PM Cong Wang wrote: > > GRE tunnel has its own header_ops, ipgre_header_ops, and sets it > conditionally. When it is set, it assumes the outer IP header is > already created before ipgre_xmit(). > > This is not true when we send packets through a raw packet socket, > where L2 headers are supposed to be constructed by user. Packet > socket calls dev_validate_header() to validate the header. But > GRE tunnel does not set dev->hard_header_len, so that check can > be simply bypassed, therefore uninit memory could be passed down > to ipgre_xmit(). Similar for dev->needed_headroom. > > dev->hard_header_len is supposed to be the length of the header > created by dev->header_ops->create(), so it should be used whenever > header_ops is set, and dev->needed_headroom should be used when it > is not set. Acked-by: Xie He Thank you for your work, Cong!