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=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE, SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 C2B66C433DB for ; Mon, 1 Feb 2021 17:59:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80C2764E9C for ; Mon, 1 Feb 2021 17:59:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232647AbhBAR7J (ORCPT ); Mon, 1 Feb 2021 12:59:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232326AbhBAR7F (ORCPT ); Mon, 1 Feb 2021 12:59:05 -0500 Received: from mail-io1-xd2c.google.com (mail-io1-xd2c.google.com [IPv6:2607:f8b0:4864:20::d2c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E39AC06174A for ; Mon, 1 Feb 2021 09:58:25 -0800 (PST) Received: by mail-io1-xd2c.google.com with SMTP id 16so18360454ioz.5 for ; Mon, 01 Feb 2021 09:58:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Bv8ZgkdpbtWRz3CeKeqPHjo/hOCKsBVIEdmTNlxLJSM=; b=klKDnUELxUZeEjyVuPIjtkORiqDrPDKxzUfGKgFJ8y8IYEVq7fDn+tN4RCOOYQJDIi yvj4eVFn2BjhA5at4JWsUXeIa3B2lzIkzfeZwKMcS+4XELsCUhy/0gugDnbAeu+0K8xR UWS10sPUqt7GwwHrkhURpyvJcuU2giHTUmrvopCEgnHfx1KiMqbB9CUxqlERhf2IX5aL jl5TosryvAyFvAosWd0Wyvhd0vEy4u1cqL5KbIy1RyeXlXUiAei/U9tmhXNypbbM4GuR d/NPY0RPjtGKTMpiZwDTl5EY+i8TQGVorYk686FAkIaX6iM2zDcodSx5pFSFHAG8wBB+ G/Kw== 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=Bv8ZgkdpbtWRz3CeKeqPHjo/hOCKsBVIEdmTNlxLJSM=; b=rjsYcynVHjd6okNz9+MV6x6LDaQ0Q/fAeMBJttedHHLi0sobTAcbKdq2+ZcNZ2Fb32 mUNSQ6bMiF3u1DQUG6LTQStXwkhS35B9I8ksDwhRtpWfKrDS7xsyn5s6ZVjDOITMJtpZ jraKimRqAv7xzvns3VLSWDD/w0LOI/h8jC4kPBIa+mfcGmcZa1A//LEIeptJYLn2F1qE tF8o2cTYbTPGa7hD17iu2TnYhZ/JRpIahDw65dPu9+oDj5eR28vGAfrJXI1C3FcROW4+ h0xdvHiC/N1p15Fa7eKdJErKrPub/4Ot2KINOvhZOjj43eGaA67oaq4Ajzo7RgaurqYc tsmA== X-Gm-Message-State: AOAM532OS8/7/EryT3r7cSGfn9RRIMP8fshubbT/C8tLxa8hc0UazBo4 zrGpmekbmZGF5F07KFP6/a5zpfjLfDBxYnwl2813VQ== X-Google-Smtp-Source: ABdhPJworOiTAhpDnz2geF6mGwnmzvskFQFo+HEu27UpDCq/rJieGNrWIG4qKLQUHm18Mj12jU/n1y9UKsQq4odITi4= X-Received: by 2002:a02:e87:: with SMTP id 129mr15622009jae.34.1612202304740; Mon, 01 Feb 2021 09:58:24 -0800 (PST) MIME-Version: 1.0 References: <20210201160420.2826895-1-elver@google.com> In-Reply-To: From: Eric Dumazet Date: Mon, 1 Feb 2021 18:58:12 +0100 Message-ID: Subject: Re: [PATCH net-next] net: fix up truesize of cloned skb in skb_prepare_for_shift() To: Marco Elver Cc: Christoph Paasch , LKML , kasan-dev , David Miller , Jakub Kicinski , Jonathan Lemon , Willem de Bruijn , linmiaohe , Guillaume Nault , Dongseok Yi , Yadu Kishore , Al Viro , netdev , Alexander Potapenko , syzbot Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 1, 2021 at 6:34 PM Marco Elver wrote: > > On Mon, 1 Feb 2021 at 17:50, Christoph Paasch > > just a few days ago we found out that this also fixes a syzkaller > > issue on MPTCP (https://github.com/multipath-tcp/mptcp_net-next/issues/136). > > I confirmed that this patch fixes the issue for us as well: > > > > Tested-by: Christoph Paasch > > That's interesting, because according to your config you did not have > KFENCE enabled. Although it's hard to say what exactly caused the > truesize mismatch in your case, because it clearly can't be KFENCE > that caused ksize(kmalloc(S))!=ksize(kmalloc(S)) for you. Indeed, this seems strange. This might be a different issue. Maybe S != S ;)