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=-13.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham 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 A9F27C00523 for ; Wed, 8 Jan 2020 06:14:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6ED2B206DB for ; Wed, 8 Jan 2020 06:14:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Zj8kKYVX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726390AbgAHGOn (ORCPT ); Wed, 8 Jan 2020 01:14:43 -0500 Received: from mail-qt1-f193.google.com ([209.85.160.193]:36963 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725773AbgAHGOm (ORCPT ); Wed, 8 Jan 2020 01:14:42 -0500 Received: by mail-qt1-f193.google.com with SMTP id w47so1921169qtk.4 for ; Tue, 07 Jan 2020 22:14:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=IL5H6BVWsjOKu38tp80zn0Zw6bpfmA7mi1czq+34HME=; b=Zj8kKYVXNnHKwFkoDYLuTkP1arcL+pmlPQk+IZm4dmruOQG90yzNhW0cCQtwAALejD BNR7U3THo+546LQBodb3/TI9eO/l2O28b+l9X1ukHcJ+IxoWRWWHjS6I5l+apJ/eJEdN H5nXpy5x/qZ/6hZFLftn7mnlz/iL6loct5GOKHR63hl6yGRRSl6ybnXd+8m8CekFhOLd nkMADCalAaBGtL9Pue4XQcxbEFDcV6w7ZXiFwX+fhbUkMZUW9pWlUWLKrrUH8qifGmwq i44YoFGmYqJ2pLXID3DwRu4U0PCobay8PIi0yUSVNlGnrXppPxrbhR2To/F3I0sJ5O75 3SJA== 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=IL5H6BVWsjOKu38tp80zn0Zw6bpfmA7mi1czq+34HME=; b=QlR6RGXFGW4KZOgeAxA/4DLNhE/R65MFPYTWqDkEM42l8Xwo0bH2ECSke4j4u3mEYa o1Y+agDK+ESS+3S72QXIFlIAczYF1AY5MdGRR5vNBPYPZURZ0ixOu0LHr/Mcl0Tr5MMD HXI/NQltkgNRLhNNAZ/YUmcinIC+ZmIX8if49Qmj9Jcffc3+0NT7GwHltyb91kTWB/nq y5+K5F0g8nPSxhHw6WyNaxiLRJhQiDzWvHej2BD9uSI535AD6sPoE8ISv3TBVH2qiFfX 5pDrTBCvjDXN//P+OIQT27Ud6HKjQRpwqOpkyi70hFKwqmzCqcA2K7NT16Lfwb7OHIO/ /GJQ== X-Gm-Message-State: APjAAAVtaGkbWdUwT51spV/Ty8LHeLOkLzxD8wXRuej+4ja7m/vZu646 s64UlFz2xRyUIBbYuALQSDJQGMULJQAyOS6UNaAAwg== X-Google-Smtp-Source: APXvYqz7sFMRqKoX5sVA8toZHcYkBZYhu0sU96m9RuKT1xWr5EvpdX+n+EhLZYaeVgbULU13Iv/MzAu024m4/mkhaR0= X-Received: by 2002:ac8:30f7:: with SMTP id w52mr2234007qta.380.1578464081688; Tue, 07 Jan 2020 22:14:41 -0800 (PST) MIME-Version: 1.0 References: <0000000000003683a5059b9aa99c@google.com> In-Reply-To: <0000000000003683a5059b9aa99c@google.com> From: Dmitry Vyukov Date: Wed, 8 Jan 2020 07:14:30 +0100 Message-ID: Subject: Re: INFO: rcu detected stall in pipe_release (2) To: syzbot , Daniel Axtens , Tetsuo Handa Cc: Andrew Morton , Christian Brauner , Kees Cook , LKML , Andy Lutomirski , Ingo Molnar , Peter Zijlstra , syzkaller-bugs , Thomas Gleixner , Will Drewry Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 8, 2020 at 7:04 AM syzbot wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: ae608821 Merge tag 'trace-v5.5-rc5' of git://git.kernel.or.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=10a30876e00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=db5ff86cbb23b415 > dashboard link: https://syzkaller.appspot.com/bug?extid=1e8dd3a6665d477d5835 > compiler: clang version 9.0.0 (/home/glider/llvm/clang > 80fee25776c2fb61e74c1ecb1a523375c2500b69) > > 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+1e8dd3a6665d477d5835@syzkaller.appspotmail.com This is: #syz dup: INFO: rcu detected stall in sys_kill For details see: https://groups.google.com/g/syzkaller-bugs/c/Vv3ARjLvagc/m/nZAubeo9AQAJ https://syzkaller.appspot.com/bug?extid=de8d933e7d153aa0c1bb I temporarily re-enabled smack instance and it produces another 50 stalls all over the kernel. So smack + KASAN + VMAP stack combination is sitll problematic. > rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: > (detected by 1, t=10502 jiffies, g=7173, q=85) > rcu: All QSes seen, last rcu_preempt kthread activity 10503 > (4294955373-4294944870), jiffies_till_next_fqs=1, root ->qsmask 0x0 > blkid R running task 28312 8628 8580 0x8000400a > Call Trace: > > sched_show_task+0x40f/0x560 kernel/sched/core.c:5954 > print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline] > check_cpu_stall kernel/rcu/tree_stall.h:538 [inline] > rcu_pending kernel/rcu/tree.c:2827 [inline] > rcu_sched_clock_irq+0x1861/0x1ad0 kernel/rcu/tree.c:2271 > update_process_times+0x12d/0x180 kernel/time/timer.c:1726 > tick_sched_handle kernel/time/tick-sched.c:167 [inline] > tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 > __run_hrtimer kernel/time/hrtimer.c:1517 [inline] > __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579 > hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641 > local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] > smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 > apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 > > RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] > RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x50 kernel/kcov.c:186 > Code: 84 00 00 00 00 00 55 48 89 e5 53 48 89 fb e8 13 00 00 00 48 8b 3d f4 > f4 ed 07 48 89 de e8 84 f4 3b 00 5b 5d c3 cc 48 8b 04 24 <65> 48 8b 0c 25 > c0 1d 02 00 65 8b 15 38 5f 8b 7e f7 c2 00 01 1f 00 > RSP: 0018:ffffc900023079b8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 > RAX: ffffffff814897d3 RBX: 0000000000000000 RCX: ffff88808c84a240 > RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea000251a840 > RBP: ffffc900023079e0 R08: dffffc0000000000 R09: fffffbfff12c962d > R10: fffffbfff12c962d R11: 0000000000000000 R12: dffffc0000000000 > R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff88808fb67538 > free_thread_stack+0x168/0x590 kernel/fork.c:280 > release_task_stack kernel/fork.c:440 [inline] > put_task_stack+0xa3/0x130 kernel/fork.c:451 > finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 > context_switch kernel/sched/core.c:3388 [inline] > __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 > preempt_schedule_common kernel/sched/core.c:4236 [inline] > preempt_schedule+0xdb/0x120 kernel/sched/core.c:4261 > ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50 > __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] > _raw_spin_unlock_irqrestore+0xcc/0xe0 kernel/locking/spinlock.c:191 > spin_unlock_irqrestore include/linux/spinlock.h:393 [inline] > __wake_up_common_lock kernel/sched/wait.c:125 [inline] > __wake_up_sync_key+0xe2/0x150 kernel/sched/wait.c:190 > pipe_release+0x17b/0x330 fs/pipe.c:709 > __fput+0x2e4/0x740 fs/file_table.c:280 > ____fput+0x15/0x20 fs/file_table.c:313 > task_work_run+0x17e/0x1b0 kernel/task_work.c:113 > exit_task_work include/linux/task_work.h:22 [inline] > do_exit+0x5f2/0x2000 kernel/exit.c:801 > do_group_exit+0x15c/0x2b0 kernel/exit.c:899 > __do_sys_exit_group+0x17/0x20 kernel/exit.c:910 > __se_sys_exit_group+0x14/0x20 kernel/exit.c:908 > __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:908 > do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x7f3a61a3a1e8 > Code: Bad RIP value. > RSP: 002b:00007ffe3c81a5e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f3a61a3a1e8 > RDX: 0000000000000002 RSI: 000000000000003c RDI: 0000000000000002 > RBP: 00007f3a61d0f840 R08: 00000000000000e7 R09: ffffffffffffffa8 > R10: 00007f3a61d15740 R11: 0000000000000246 R12: 00007f3a61d0f840 > R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 > rcu: rcu_preempt kthread starved for 10537 jiffies! g7173 f0x2 > RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 > rcu: RCU grace-period kthread stack dump: > rcu_preempt R running task 29032 10 2 0x80004000 > Call Trace: > context_switch kernel/sched/core.c:3385 [inline] > __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 > schedule+0x181/0x210 kernel/sched/core.c:4155 > schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 > rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] > rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 > kthread+0x332/0x350 kernel/kthread.c:255 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > > --- > 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. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0000000000003683a5059b9aa99c%40google.com.