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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CEDA5C77B73 for ; Wed, 24 May 2023 15:11:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235966AbjEXPLj (ORCPT ); Wed, 24 May 2023 11:11:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235865AbjEXPLi (ORCPT ); Wed, 24 May 2023 11:11:38 -0400 Received: from mail-yb1-xb30.google.com (mail-yb1-xb30.google.com [IPv6:2607:f8b0:4864:20::b30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F77818E for ; Wed, 24 May 2023 08:11:35 -0700 (PDT) Received: by mail-yb1-xb30.google.com with SMTP id 3f1490d57ef6-bab8f66d3a2so1561746276.3 for ; Wed, 24 May 2023 08:11:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=paul-moore.com; s=google; t=1684941094; x=1687533094; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=HqqN7STJH2LoGCrwrill0kIUbhodoox7qSOdJoH92o8=; b=EFehSwqT4xP3Dsgl9bmiZS3CIEPYx7oE8YP/dagGWOYw22jxpzPgKbLa+z/ZmWlOwX sbDUYJK1SF3CUXwmwlypvEibDRI9nS0D2DX+1qVKP8T5GElGdyojL5b5LWCxsc3eJabx TAQKujaM7/wvTwHsVvSiJVHxSnfB7NkBNEEEy0m67Z1moTU+gNl374iCNxVEG4RM6sZW 9VpQVnKwVC9ltwPttucugKAFTxlXCjokxJbv+TppvKl4cWmkpEiNAzPg+S0RLyaHL2T5 8746YxI3TCs5u9PRcnTlk2UxGUeRQTfCZaRTwVv3wIyHrEIF5SBSX4BfjZzx6oLbdaGJ X1Tg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684941094; x=1687533094; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=HqqN7STJH2LoGCrwrill0kIUbhodoox7qSOdJoH92o8=; b=KnAL/sdyizs6fGJbsAgonkwPkmX4dlGUx56ZeeWRICwCPdVsw6TW1kPBWMosTwuQvi UZCSWLnV9ggDIbbvS9avsuaeEU0Plou5sb1DIrJw0OkH8z1jlwkdPTEBEcDBakh/wala 3asILk2e/kA+5UAdxgwGKqFH5yIimwnF8uffV9FdfClB+WzDPedk5DG158fL6P2FCpxt rVBwqmRdffLg4HPsqGTjoNNUCcGaMRvE0MzB/wWQ2x9J4Gx3I9pd1hhyDb0n2VB6d5vn scX+a4ITjfCIUYwIlekis+7mbO+Z0UOx+k3ZYSF6hjEDdKDsr+BgkkBScBxQf2Ts+OUN 8NPg== X-Gm-Message-State: AC+VfDyDQ26wSrU4mxk7mmCdj1bVWbLc4vciBrWqiX+hoFdrltm4mGeT brB9azpvdb0rLF2CIMxba53Je5pSm3G5sR4rnRxs X-Google-Smtp-Source: ACHHUZ7h5ztNlZIBSemxHTQoG+pdx9LkR0k/enQ4NmhLwlTYFQsLUTSuCVlVruca0i0KPIlmFIwlSwu/781g1QjhNk8= X-Received: by 2002:a0d:cc95:0:b0:561:7ec:cf90 with SMTP id o143-20020a0dcc95000000b0056107eccf90mr18983019ywd.42.1684941094273; Wed, 24 May 2023 08:11:34 -0700 (PDT) MIME-Version: 1.0 References: <000000000000be039005fc540ed7@google.com> <00000000000018faf905fc6d9056@google.com> In-Reply-To: <00000000000018faf905fc6d9056@google.com> From: Paul Moore Date: Wed, 24 May 2023 11:11:23 -0400 Message-ID: Subject: Re: [syzbot] [reiserfs?] INFO: task hung in flush_old_commits To: linux-security-module@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, reiserfs-devel@vger.kernel.org, roberto.sassu@huawei.com, syzkaller-bugs@googlegroups.com, syzbot Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, May 24, 2023 at 5:59=E2=80=AFAM syzbot wrote: > > syzbot has bisected this issue to: > > commit d82dcd9e21b77d338dc4875f3d4111f0db314a7c > Author: Roberto Sassu > Date: Fri Mar 31 12:32:18 2023 +0000 > > reiserfs: Add security prefix to xattr name in reiserfs_security_writ= e() > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=3D11c3963928= 0000 > start commit: 421ca22e3138 Merge tag 'nfs-for-6.4-2' of git://git.linux= -.. > git tree: upstream > final oops: https://syzkaller.appspot.com/x/report.txt?x=3D13c3963928= 0000 > console output: https://syzkaller.appspot.com/x/log.txt?x=3D15c3963928000= 0 > kernel config: https://syzkaller.appspot.com/x/.config?x=3D7d8067683055e= 3f5 > dashboard link: https://syzkaller.appspot.com/bug?extid=3D0a684c061589dcc= 30e51 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=3D14312791280= 000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=3D12da860528000= 0 > > Reported-by: syzbot+0a684c061589dcc30e51@syzkaller.appspotmail.com > Fixes: d82dcd9e21b7 ("reiserfs: Add security prefix to xattr name in reis= erfs_security_write()") > > For information about bisection process see: https://goo.gl/tpsmEJ#bisect= ion Roberto, I think we need to resolve this somehow. As I mentioned earlier, I don't believe this to be a fault in your patch, rather that patch simply triggered a situation that had not been present before, likely because the reiserfs code always failed when writing LSM xattrs. Regardless, we still need to fix the deadlocks that sysbot has been reporting. Has anyone dug into the reiserfs code to try and resolve the deadlock? Considering the state of reiserfs, I'm guessing no one has, and I can't blame them; I personally would have a hard time justifying significant time spent on reiserfs at this point. Unless someone has any better ideas, I'm wondering if we shouldn't just admit defeat with reiserfs and LSM xattrs and disable/remove the reiserfs LSM xattr support? Given the bug that Roberto was fixing with the patch in question, it's unlikely this was working anyway. -- paul-moore.com