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 3A49CC43603 for ; Thu, 12 Dec 2019 23:33:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0C3DA214AF for ; Thu, 12 Dec 2019 23:33:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731262AbfLLXdL (ORCPT ); Thu, 12 Dec 2019 18:33:11 -0500 Received: from mail-io1-f72.google.com ([209.85.166.72]:46498 "EHLO mail-io1-f72.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731170AbfLLXdL (ORCPT ); Thu, 12 Dec 2019 18:33:11 -0500 Received: by mail-io1-f72.google.com with SMTP id p206so425125iod.13 for ; Thu, 12 Dec 2019 15:33:10 -0800 (PST) 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=uPmT7H1u4tQQr91gsmUmlGu51pKPCSerupF0+mBYR+A=; b=BlZnm9YH0y6rnUig/2/FVQfgklLRpgY5VW1iI5rBnfkJpV+Daqe0UX92kNxx7CrK9E m7CaDBT/s6CwLx2VudL6n4qjuPa77BMkMEuIjmjxErlRtOqMPAbf1Rcmh+QgqRkQkfLo wqK8ip7oqqNDgdygGPpjFVCEBEH1P1X6giRmmrwgP0gidwJlL2aKz3XJkhqdYynBEe+7 vO0GATTO0FFMFj58mhVfw/++4eZrmRpUJ/GLWaG/eiXXGBWftSY5VGXW7Q/xig88BVl5 HzHoMsoypwSXbrVgV7ihEcOdg5dJXkNNEJA533rk+Xc0X8GnTjT1lKv82tgekKDo9x8t a4bw== X-Gm-Message-State: APjAAAUJgU7XZ6jleRHvZnr1IGPkL/yQm2gvq83G0KhAwX9u8JmGPytG TeMLOjUszY5fetRP1K73t9g4RjzQyIV6PXgWooiw3aIXJ0Rc X-Google-Smtp-Source: APXvYqxRonIBYq3QlOSfLTDmRhr3h1LOT5KDkHtrZySgylant5xgPnByJCRl6xs7oY/bbF7kt3LOHlPciackUCos0rlrM+RWe26+ MIME-Version: 1.0 X-Received: by 2002:a92:7606:: with SMTP id r6mr10592785ilc.120.1576193590352; Thu, 12 Dec 2019 15:33:10 -0800 (PST) Date: Thu, 12 Dec 2019 15:33:10 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000000ce4b105998a2b08@google.com> Subject: KCSAN: data-race in add_timer / timer_clear_idle (2) From: syzbot To: a@unstable.cc, b.a.t.m.a.n@lists.open-mesh.org, davem@davemloft.net, elver@google.com, linux-kernel@vger.kernel.org, mareklindner@neomailbox.ch, netdev@vger.kernel.org, sven@narfation.org, sw@simonwunderlich.de, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: ef798c30 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=156e052ee00000 kernel config: https://syzkaller.appspot.com/x/.config?x=8077a73bd604a9d4 dashboard link: https://syzkaller.appspot.com/bug?extid=c051abeff5e2e8ac40f0 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+c051abeff5e2e8ac40f0@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in add_timer / timer_clear_idle read to 0xffff88812be1b6e4 of 1 bytes by task 23 on cpu 1: forward_timer_base kernel/time/timer.c:892 [inline] __mod_timer kernel/time/timer.c:1009 [inline] mod_timer kernel/time/timer.c:1100 [inline] add_timer+0x3a6/0x550 kernel/time/timer.c:1136 __queue_delayed_work+0x13b/0x1d0 kernel/workqueue.c:1649 queue_delayed_work_on+0xf3/0x110 kernel/workqueue.c:1674 queue_delayed_work include/linux/workqueue.h:509 [inline] batadv_mcast_start_timer net/batman-adv/multicast.c:71 [inline] batadv_mcast_mla_update+0x11ad/0x19e0 net/batman-adv/multicast.c:949 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269 worker_thread+0xa0/0x800 kernel/workqueue.c:2415 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 write to 0xffff88812be1b6e4 of 1 bytes by task 0 on cpu 0: timer_clear_idle+0x42/0x50 kernel/time/timer.c:1675 tick_nohz_restart_sched_tick kernel/time/tick-sched.c:839 [inline] __tick_nohz_idle_restart_tick+0x36/0x1b0 kernel/time/tick-sched.c:1140 tick_nohz_idle_exit+0x1af/0x1e0 kernel/time/tick-sched.c:1181 do_idle+0xb1/0x280 kernel/sched/idle.c:276 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:355 rest_init+0xec/0xf6 init/main.c:452 arch_call_rest_init+0x17/0x37 start_kernel+0x838/0x85e init/main.c:786 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490 x86_64_start_kernel+0x72/0x76 arch/x86/kernel/head64.c:471 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-syzkaller #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.