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=-0.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 72D52C0044C for ; Thu, 1 Nov 2018 16:52:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2DBE220830 for ; Thu, 1 Nov 2018 16:52:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2DBE220830 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727525AbeKBBzv (ORCPT ); Thu, 1 Nov 2018 21:55:51 -0400 Received: from mail-it1-f198.google.com ([209.85.166.198]:57638 "EHLO mail-it1-f198.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726115AbeKBBzu (ORCPT ); Thu, 1 Nov 2018 21:55:50 -0400 Received: by mail-it1-f198.google.com with SMTP id q7so2283060itj.7 for ; Thu, 01 Nov 2018 09:52:04 -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=WVOutJVhm4dhQe7McfVDIb46g0xOU4UEvTNTRuFh36g=; b=KkzXF81aXVgYCeu2nIuF0QiE0cAbhseaHmOaT3rKkIowrDgJw0rFjt+22afIBmJBHm RKESKj3a63K87mReHH11gykBgolBRK0tWFBr26aHJV+5gjznY7ndHU5V7qXjQVLaFS8g l1yXiRz9Vhafd+2z2KwjAY+aLTVSQlyqiIDAeYwsmjeIWuPo5vGdhuZdGsobwJgGdW5g Ldi20w7PKlZkZ7ZCDWQgj7QvpnTbHzsP4DxBLpIVBl8keev9jBX7QxsB0VdjlVwNV7iv Inp7y643fJxGu/3wjR0S3A3utHNj990EGVSg0GQZI9uwkGlCicN4sUFBtegPYdt4SRTK 36vg== X-Gm-Message-State: AGRZ1gJ8NzjLyVm8DhalwcNlJj5EVvjyrEI70u6GybIki/OVoAZf53kC X1L+hf7euxy62B3rMMu9ny7SF8qTi5yNxZV3h1oVzzxYdsTN X-Google-Smtp-Source: AJdET5dQdb/CTRYLgpUUY19Q13DrbzZMfmT/PSbnvizL1MQMH9PvVN4oIlECfL6yUIIESsjJJ6DQLQHgSQk7msClTlCTzo3ADZlo MIME-Version: 1.0 X-Received: by 2002:a24:2ecd:: with SMTP id i196-v6mr6124932ita.7.1541091124039; Thu, 01 Nov 2018 09:52:04 -0700 (PDT) Date: Thu, 01 Nov 2018 09:52:04 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000003dc7805799d3dd8@google.com> Subject: INFO: task hung in flush_workqueue From: syzbot To: ezequiel@collabora.com, hansverk@cisco.com, keescook@chromium.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@kernel.org, sakari.ailus@linux.intel.com, scileont@gmail.com, syzkaller-bugs@googlegroups.com 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: 4db9d11bcbef Add linux-next specific files for 20181101 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=16bb4425400000 kernel config: https://syzkaller.appspot.com/x/.config?x=2a22859d870756c1 dashboard link: https://syzkaller.appspot.com/bug?extid=69780d144754b8071f4b compiler: gcc (GCC) 8.0.1 20180413 (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+69780d144754b8071f4b@syzkaller.appspotmail.com IPVS: wrr: SCTP 172.20.20.170:0 - no destination available EXT4-fs error (device sda1): ext4_remount:5216: Abort forced by user EXT4-fs (sda1): Remounting filesystem read-only INFO: task syz-executor0:12469 blocked for more than 140 seconds. Not tainted 4.19.0-next-20181101+ #103 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D21208 12469 11524 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 schedule_timeout+0x1cc/0x260 kernel/time/timer.c:1780 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x427/0x8a0 kernel/sched/completion.c:136 flush_workqueue+0x742/0x1e10 kernel/workqueue.c:2707 flush_scheduled_work include/linux/workqueue.h:599 [inline] vim2m_stop_streaming+0x7c/0x2c0 drivers/media/platform/vim2m.c:811 __vb2_queue_cancel+0x171/0xd20 drivers/media/common/videobuf2/videobuf2-core.c:1823 vb2_core_queue_release+0x26/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2229 vb2_queue_release+0x15/0x20 drivers/media/common/videobuf2/videobuf2-v4l2.c:837 v4l2_m2m_ctx_release+0x2a/0x35 drivers/media/v4l2-core/v4l2-mem2mem.c:931 vim2m_release+0xe6/0x150 drivers/media/platform/vim2m.c:977 v4l2_release+0x224/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:456 __fput+0x3bc/0xa70 fs/file_table.c:279 ____fput+0x15/0x20 fs/file_table.c:312 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: Bad RIP value. RSP: 002b:00007fac56403c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fac564046d4 R13: 00000000004efe32 R14: 00000000004cc6e0 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1009: #0: 00000000e84c6b38 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by udevd/3501: 1 lock held by rsyslogd/5533: #0: 000000006dc20f7b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5623: #0: 0000000031a1a60d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000015d4fdea (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5624: #0: 000000004fa09fe3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e2ec2afa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5625: #0: 000000000b6bdc9d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000000ad48c56 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5626: #0: 000000007720a28b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000090a35a2c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5627: #0: 00000000c511ad6c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000beb7d44a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5628: #0: 000000009dbb3d36 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000de06e26d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5629: #0: 00000000ccb92b09 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000191edc69 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by kworker/0:4/7412: #0: 00000000062cd1fa ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 00000000062cd1fa ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000062cd1fa ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000062cd1fa ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000062cd1fa ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000062cd1fa ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000062cd1fa ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 000000003fe6abd7 ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 2 locks held by syz-executor0/12469: #0: 00000000e32d2d8c (&mdev->req_queue_mutex){+.+.}, at: v4l2_release+0x1d7/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:455 #1: 0000000023d4a01f (&dev->dev_mutex){+.+.}, at: vim2m_release+0xbc/0x150 drivers/media/platform/vim2m.c:976 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1009 Comm: khungtaskd Not tainted 4.19.0-next-20181101+ #103 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb4c/0x1060 kernel/hung_task.c:289 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.004 msecs NMI backtrace for cpu 0 CPU: 0 PID: 3501 Comm: udevd Not tainted 4.19.0-next-20181101+ #103 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0xc9/0x4c20 kernel/locking/lockdep.c:3206 Code: c7 40 24 f2 f2 f2 f2 c7 40 28 04 f2 f2 f2 c7 40 2c f2 f2 f2 f2 c7 40 30 00 f2 f2 f2 c7 40 34 f2 f2 f2 f2 c7 40 38 00 f2 f2 f2 40 3c f2 f2 f2 f2 c7 40 40 00 f2 f2 f2 c7 40 44 f2 f2 f2 f2 c7 RSP: 0018:ffff8801c7387190 EFLAGS: 00000082 RAX: ffffed0038e70e46 RBX: 1ffff10038e70eae RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8801c6a42b18 RBP: ffff8801c7387518 R08: 0000000000000001 R09: 0000000000000001 R10: ffffed0038e6c6f7 R11: ffff8801c73637bf R12: ffff8801c7378580 R13: ffff8801c6a42b18 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fa5bdbf37a0(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001c72bd000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000020000000 DR2: 0000000020000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000010602 Call Trace: lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x61/0x80 kernel/locking/spinlock.c:160 spin_lock_irq include/linux/spinlock.h:354 [inline] ep_scan_ready_list+0x4cb/0x1050 fs/eventpoll.c:710 ep_send_events fs/eventpoll.c:1713 [inline] ep_poll+0x572/0x13d0 fs/eventpoll.c:1840 do_epoll_wait+0x1b0/0x200 fs/eventpoll.c:2198 __do_sys_epoll_wait fs/eventpoll.c:2208 [inline] __se_sys_epoll_wait fs/eventpoll.c:2205 [inline] __x64_sys_epoll_wait+0x97/0xf0 fs/eventpoll.c:2205 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fa5bd307943 Code: 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 83 3d b5 dc 2a 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 3b c4 00 00 48 89 04 24 RSP: 002b:00007ffd0f4810e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007fa5bd307943 RDX: 0000000000000008 RSI: 00007ffd0f4811e0 RDI: 000000000000000a RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000bb8 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000000db8230 R15: 0000000000db2250 --- This bug is generated by a bot. 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