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=-7.8 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,MENTIONS_GIT_HOSTING, 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 39B8CC432BE for ; Tue, 3 Aug 2021 14:57:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 208EE60243 for ; Tue, 3 Aug 2021 14:57:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235892AbhHCO5a (ORCPT ); Tue, 3 Aug 2021 10:57:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37092 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234206AbhHCO53 (ORCPT ); Tue, 3 Aug 2021 10:57:29 -0400 Received: from mail-yb1-xb2d.google.com (mail-yb1-xb2d.google.com [IPv6:2607:f8b0:4864:20::b2d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 648E9C061757; Tue, 3 Aug 2021 07:57:17 -0700 (PDT) Received: by mail-yb1-xb2d.google.com with SMTP id a93so16123872ybi.1; Tue, 03 Aug 2021 07:57:17 -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=9IoTpQSoFN8X9feSI035kPuC1yq++XFdeyD5Oq4YGKU=; b=tfU660ceP9Cw9lVo5xVG4iqGiQldb5dnzTWtjqNPtgZ59X5oh/8gmpazWSHzOiYRHs 4YPnjMgkpVunHrAZj+hd+fqCPVyGNFqT0oCt795YrACgmSxgu7d2SsSCoiz5H/HbBXEa mqZIagubbvvRpG3QhQXy0PMZY6fgAOnaqFt8i/z3YQYs2xdVnB0UrMpHzt8eEXUTQ8Jy IhiPfdb2rJirBFo3vDdH0lSO8nIfPqbZ6b7Sla5JZJoptP17RzqoLk+SAxwkBAkDZUv2 Eb5RaXl6wj3rGr4Aso8br/GioipTt1kKzLXHTiaVcGeCymdzYPCCGKZS3ODB2xRkE9po 2z6Q== 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=9IoTpQSoFN8X9feSI035kPuC1yq++XFdeyD5Oq4YGKU=; b=A9HkzsNA0qaOIJmdkSEaZOXtZv6M0/M6vet31cUOszRXtgWciCVqfqaJUq9OMRmst3 trFHwDGWHJYzGDOJ5lDQkZszIcSmxQQY8KD3NnPxl1AskeVluuAUN8rKW+nKW1/oeFhV MeH/Xv88CU62/xCPSH4Lo6jMrfG9tXZ3K+CDA2gl3a1SI4+NqGPOv409GWqw0HOs7tXL RgBIa5hxyXlvE2P46mAF9kpFTNvqbjUTYtqv6nXL4eySlSUsueo4bmxPfPB505CE2lHM tOTAFsfxWWZrXQUVV4w2qF9X71JUxj333Uq+KdmsBY1b2sim/mj0Gv9oWA3UgyGGXWZe Hcmg== X-Gm-Message-State: AOAM530IkRVeX4ikxTc8omYbH9gfs3Bfr5uYv+PRmR3R9eM3k/tfRrUp 337zDgsuvQSEtBLeiXcfUMJeLVBzksx++P7zh90= X-Google-Smtp-Source: ABdhPJzznB420tcQq5+eEEI7CtIXVisjpepyS5Oyo434ofvSlrzRcz+2mrznrUI0oge3JgIa+IQmUWB6vwiOZr23O58= X-Received: by 2002:a25:1546:: with SMTP id 67mr29005241ybv.331.1628002636674; Tue, 03 Aug 2021 07:57:16 -0700 (PDT) MIME-Version: 1.0 References: <4c339bea-87ff-cb41-732f-05fc5aff18fa@gmail.com> <8db71657-bd61-6b1f-035f-9a69221e7cb3@gmail.com> <98f8ec51-9d84-0e74-4c1c-a463f2d69d9d@gmail.com> In-Reply-To: <98f8ec51-9d84-0e74-4c1c-a463f2d69d9d@gmail.com> From: Sudip Mukherjee Date: Tue, 3 Aug 2021 15:56:40 +0100 Message-ID: Subject: Re: KASAN: stack-out-of-bounds in iov_iter_revert To: Pavel Begunkov Cc: Jens Axboe , io-uring@vger.kernel.org, linux-kernel Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 3, 2021 at 11:34 AM Pavel Begunkov wrote: > > On 8/3/21 8:47 AM, Sudip Mukherjee wrote: > > On Mon, Aug 2, 2021 at 12:55 PM Pavel Begunkov wrote: > >> > >> On 8/1/21 9:28 PM, Sudip Mukherjee wrote: > >>> Hi Pavel, > >>> > >>> On Sun, Aug 1, 2021 at 9:52 AM Pavel Begunkov wrote: > >>>> > >>>> On 8/1/21 1:10 AM, Pavel Begunkov wrote: > >>>>> On 7/31/21 7:21 PM, Sudip Mukherjee wrote: > >>>>>> Hi Jens, Pavel, > >>>>>> > >>>>>> We had been running syzkaller on v5.10.y and a "KASAN: > >>>>>> stack-out-of-bounds in iov_iter_revert" was being reported on it. I > >>>>>> got some time to check that today and have managed to get a syzkaller > >>>>>> reproducer. I dont have a C reproducer which I can share but I can use > >>>>>> the syz-reproducer to reproduce this with v5.14-rc3 and also with > >>>>>> next-20210730. > >>>>> > >>>>> Can you try out the diff below? Not a full-fledged fix, but need to > >>>>> check a hunch. > >>>>> > >>>>> If that's important, I was using this branch: > >>>>> git://git.kernel.dk/linux-block io_uring-5.14 > >>>> > >>>> Or better this one, just in case it ooopses on warnings. > >>> > >>> I tested this one on top of "git://git.kernel.dk/linux-block > >>> io_uring-5.14" and the issue was still seen, but after the BUG trace I > >>> got lots of "truncated wr" message. The trace is: > >> > >> That's interesting, thanks > >> Can you share the syz reproducer? > > > > Unfortunately I dont have a C reproducer, but this is the reproducer > > for syzkaller: > > Thanks. Maybe I'm not perfectly familiar with syz, but were there > any options? Like threaded, collide, etc.? Sorry, my mistake. I am still learning how syzkaller works. And I should have given the link to the report with my mail. https://elisa-builder-00.iol.unh.edu/syzkaller/report?id=959057ecd2886ff0c38cc53fa9c8eae46c1d7496 And also, I now have a C reproducer also, if that helps. -- Regards Sudip