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=-5.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS 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 E4482FA373A for ; Thu, 17 Oct 2019 12:36:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BF3042064A for ; Thu, 17 Oct 2019 12:36:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2502462AbfJQMgJ (ORCPT ); Thu, 17 Oct 2019 08:36:09 -0400 Received: from mail-io1-f70.google.com ([209.85.166.70]:43172 "EHLO mail-io1-f70.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2502451AbfJQMgJ (ORCPT ); Thu, 17 Oct 2019 08:36:09 -0400 Received: by mail-io1-f70.google.com with SMTP id i2so2997221ioo.10 for ; Thu, 17 Oct 2019 05:36:08 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=5t4yqDt+mBIkGJEjjJGiGmX6FdFp97lRinnPxkeZsbg=; b=fedkuiiFuS6gy8VyOM9grTgA/rkDVEr/45AfsvHcYNrtpOMAFQc/3qk6LNzpDSiQaH dBwGbDJbr4zICwnXkf4SocN/CJoqzjt10XJGvW2SxsRVCuAKFd0ZsMARL0Jyz/6RQLFr XCGJ4AVEQehoe4g7Zf4Js9YL957y3o2TvSuGpw2545CBSQDcLm8Q2h/LjIghYSj3rjyx F2S3iPsovkfcvO6g04xYc4MapCnK0HeNOjtlG1D/1p4HHCChTPCSLhBT1GyuY25S/2JN 6Yctnf8yq5UnwK+ORrIOr2Ijh71k/8+qymavH6SJfCrX0YmlxFlG4b14uR02+jaG5DJz t2aQ== X-Gm-Message-State: APjAAAXzGw4Dnz4WaR1PgpnXb7gWWKF2wTwYuwV/n1jEZITT3yy2xcOo Z5sE3OcurCAgaM5AJSXJkiluyJH2MfXuES8eDRqbonDphuT1 X-Google-Smtp-Source: APXvYqzB8gJtlUXLPgJonp1LfCe0tLXtXHbbpq4ADGFI8YMv/2ntWneIkikxCxslAZV/kWQ6JCcMn2qAGmAut/KPw4CjeFynQQ4/ MIME-Version: 1.0 X-Received: by 2002:a02:bb01:: with SMTP id y1mr3062982jan.117.1571315768264; Thu, 17 Oct 2019 05:36:08 -0700 (PDT) Date: Thu, 17 Oct 2019 05:36:08 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000328b2905951a7667@google.com> Subject: KCSAN: data-race in task_dump_owner / task_dump_owner From: syzbot To: adobriyan@gmail.com, akpm@linux-foundation.org, casey@schaufler-ca.com, christian@brauner.io, elver@google.com, keescook@chromium.org, kent.overstreet@gmail.com, khlebnikov@yandex-team.ru, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, mhocko@suse.com, shakeelb@google.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: d724f94f x86, kcsan: Enable KCSAN for x86 git tree: https://github.com/google/ktsan.git kcsan console output: https://syzkaller.appspot.com/x/log.txt?x=17884db3600000 kernel config: https://syzkaller.appspot.com/x/.config?x=c0906aa620713d80 dashboard link: https://syzkaller.appspot.com/bug?extid=e392f8008a294fdf8891 compiler: gcc (GCC) 9.0.0 20181231 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+e392f8008a294fdf8891@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in task_dump_owner / task_dump_owner write to 0xffff8881255bb7fc of 4 bytes by task 7804 on cpu 0: task_dump_owner+0xd8/0x260 fs/proc/base.c:1742 pid_update_inode+0x3c/0x70 fs/proc/base.c:1818 pid_revalidate+0x91/0xd0 fs/proc/base.c:1841 d_revalidate fs/namei.c:765 [inline] d_revalidate fs/namei.c:762 [inline] lookup_fast+0x7cb/0x7e0 fs/namei.c:1613 walk_component+0x6d/0xe80 fs/namei.c:1804 link_path_walk.part.0+0x5d3/0xa90 fs/namei.c:2139 link_path_walk fs/namei.c:2070 [inline] path_openat+0x14f/0x3530 fs/namei.c:3532 do_filp_open+0x11e/0x1b0 fs/namei.c:3563 do_sys_open+0x3b3/0x4f0 fs/open.c:1089 __do_sys_open fs/open.c:1107 [inline] __se_sys_open fs/open.c:1102 [inline] __x64_sys_open+0x55/0x70 fs/open.c:1102 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 write to 0xffff8881255bb7fc of 4 bytes by task 7813 on cpu 1: task_dump_owner+0xd8/0x260 fs/proc/base.c:1742 pid_update_inode+0x3c/0x70 fs/proc/base.c:1818 pid_revalidate+0x91/0xd0 fs/proc/base.c:1841 d_revalidate fs/namei.c:765 [inline] d_revalidate fs/namei.c:762 [inline] lookup_fast+0x7cb/0x7e0 fs/namei.c:1613 walk_component+0x6d/0xe80 fs/namei.c:1804 lookup_last fs/namei.c:2271 [inline] path_lookupat.isra.0+0x13a/0x5a0 fs/namei.c:2316 filename_lookup+0x145/0x2d0 fs/namei.c:2346 user_path_at_empty+0x4c/0x70 fs/namei.c:2606 user_path_at include/linux/namei.h:60 [inline] vfs_statx+0xd9/0x190 fs/stat.c:187 vfs_stat include/linux/fs.h:3188 [inline] __do_sys_newstat+0x51/0xb0 fs/stat.c:341 __se_sys_newstat fs/stat.c:337 [inline] __x64_sys_newstat+0x3a/0x50 fs/stat.c:337 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 7813 Comm: ps Not tainted 5.3.0+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.