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 98DD0C7EE23 for ; Wed, 24 May 2023 15:50:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236782AbjEXPuj (ORCPT ); Wed, 24 May 2023 11:50:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229919AbjEXPuh (ORCPT ); Wed, 24 May 2023 11:50:37 -0400 Received: from frasgout12.his.huawei.com (unknown [14.137.139.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B58D93; Wed, 24 May 2023 08:50:36 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.18.147.228]) by frasgout12.his.huawei.com (SkyGuard) with ESMTP id 4QRFj419Ltz9xFZy; Wed, 24 May 2023 23:39:04 +0800 (CST) Received: from roberto-ThinkStation-P620 (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwDXVQEvMm5kDA3ZAg--.2184S2; Wed, 24 May 2023 16:50:18 +0100 (CET) Message-ID: <813148798c14a49cbdf0f500fbbbab154929e6ed.camel@huaweicloud.com> Subject: Re: [syzbot] [reiserfs?] INFO: task hung in flush_old_commits From: Roberto Sassu To: Paul Moore , 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 Date: Wed, 24 May 2023 17:50:03 +0200 In-Reply-To: References: <000000000000be039005fc540ed7@google.com> <00000000000018faf905fc6d9056@google.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5-0ubuntu1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: LxC2BwDXVQEvMm5kDA3ZAg--.2184S2 X-Coremail-Antispam: 1UD129KBjvJXoW7CFW7ZFW8GryfJryxArW3GFg_yoW8Kw18pr WrGFnIkrsYvr1jyFn2vF1DWw1I9rZ5CrW7J3yDtryj9anaqrnrtrs29F4fW3yDCr4DCF90 v3W3uwn5Xwn5u37anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUgmb4IE77IF4wAFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Jr0_JF4l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Jr0_Gr1l84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxV AFwI0_Gr0_Gr1UM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40E x7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x 0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_ Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1V AY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAI cVC0I7IYx2IY6xkF7I0E14v26r1j6r4UMIIF0xvE42xK8VAvwI8IcIk0rVWrZr1j6s0DMI IF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr0_GrUvcSsGvfC2 KfnxnUUI43ZEXa7IU1zuWJUUUUU== X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAQAHBF1jj42dyAADso X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2023-05-24 at 11:11 -0400, Paul Moore wrote: > On Wed, May 24, 2023 at 5:59 AM 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_write() > > > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11c39639280000 > > 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=13c39639280000 > > console output: https://syzkaller.appspot.com/x/log.txt?x=15c39639280000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=7d8067683055e3f5 > > dashboard link: https://syzkaller.appspot.com/bug?extid=0a684c061589dcc30e51 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14312791280000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12da8605280000 > > > > Reported-by: syzbot+0a684c061589dcc30e51@syzkaller.appspotmail.com > > Fixes: d82dcd9e21b7 ("reiserfs: Add security prefix to xattr name in reiserfs_security_write()") > > > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > > 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. Hi Paul ok, I will try. Roberto > 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roberto Sassu Subject: Re: [syzbot] [reiserfs?] INFO: task hung in flush_old_commits Date: Wed, 24 May 2023 17:50:03 +0200 Message-ID: <813148798c14a49cbdf0f500fbbbab154929e6ed.camel@huaweicloud.com> References: <000000000000be039005fc540ed7@google.com> <00000000000018faf905fc6d9056@google.com> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-ID: Content-Type: text/plain; charset="windows-1252" To: Paul Moore , 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 On Wed, 2023-05-24 at 11:11 -0400, Paul Moore wrote: > On Wed, May 24, 2023 at 5:59=E2=80=AFAM syzbot > wrote: > > syzbot has bisected this issue to: > >=20 > > commit d82dcd9e21b77d338dc4875f3d4111f0db314a7c > > Author: Roberto Sassu > > Date: Fri Mar 31 12:32:18 2023 +0000 > >=20 > > reiserfs: Add security prefix to xattr name in reiserfs_security_wr= ite() > >=20 > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=3D11c39639= 280000 > > start commit: 421ca22e3138 Merge tag 'nfs-for-6.4-2' of git://git.lin= ux-.. > > git tree: upstream > > final oops: https://syzkaller.appspot.com/x/report.txt?x=3D13c39639= 280000 > > console output: https://syzkaller.appspot.com/x/log.txt?x=3D15c39639280= 000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=3D7d806768305= 5e3f5 > > dashboard link: https://syzkaller.appspot.com/bug?extid=3D0a684c061589d= cc30e51 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=3D143127912= 80000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=3D12da8605280= 000 > >=20 > > Reported-by: syzbot+0a684c061589dcc30e51@syzkaller.appspotmail.com > > Fixes: d82dcd9e21b7 ("reiserfs: Add security prefix to xattr name in re= iserfs_security_write()") > >=20 > > For information about bisection process see: https://goo.gl/tpsmEJ#bise= ction >=20 > 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. Hi Paul ok, I will try. Roberto > 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. >=20 > -- > paul-moore.com