INFO: task kworker/u4:7:31768 blocked for more than 140 seconds. Not tainted 4.20.0-rc7+ #376 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:7 D12016 31768 2 0x80000000 Workqueue: events_unbound fsnotify_connector_destroy_workfn 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 __synchronize_srcu+0x20a/0x2d0 kernel/rcu/srcutree.c:941 synchronize_srcu_expedited kernel/rcu/srcutree.c:966 [inline] synchronize_srcu+0x1d6/0x5b0 kernel/rcu/srcutree.c:1017 fsnotify_connector_destroy_workfn+0x44/0xa0 fs/notify/mark.c:176 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 INFO: task kworker/u4:2:32315 blocked for more than 140 seconds. Not tainted 4.20.0-rc7+ #376 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:2 D21256 32315 2 0x80000000 Workqueue: events_unbound fsnotify_mark_destroy_workfn 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 __synchronize_srcu+0x20a/0x2d0 kernel/rcu/srcutree.c:941 synchronize_srcu+0x44c/0x5b0 kernel/rcu/srcutree.c:1019 fsnotify_mark_destroy_workfn+0x1be/0x510 fs/notify/mark.c:799 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 3 locks held by kworker/0:1/12: 4 locks held by kworker/u4:1/21: #0: 000000002c5752cc ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 000000002c5752cc ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000002c5752cc ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000002c5752cc ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000002c5752cc ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000002c5752cc ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000002c5752cc ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 00000000e52f3d41 (net_cleanup_work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 #2: 0000000004606366 (pernet_ops_rwsem){++++}, at: cleanup_net+0x13f/0xb10 net/core/net_namespace.c:518 #3: 00000000065cd332 (rcu_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline] #3: 00000000065cd332 (rcu_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited.constprop.58+0x7af/0x9d0 kernel/rcu/tree_exp.h:620 1 lock held by khungtaskd/1019: #0: 00000000ad23a553 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5874: #0: 00000000c4fd9f1a (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5965: #0: 0000000044bcfcde (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a5282b27 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5966: #0: 00000000ade6e14b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000008ec6e4f7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5967: #0: 000000009809a1d9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000097c794c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5968: #0: 0000000047ad9a28 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000050943ed3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5969: #0: 00000000208eb7fa (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c2e0382a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5970: #0: 00000000b8fe070c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000f678a10f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5971: #0: 00000000d6d54fb5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000204d8261 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by kworker/u4:7/31768: #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 0000000097931562 (connector_reaper_work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 2 locks held by kworker/u4:2/32315: #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000081f6fd0a ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 0000000007421944 ((reaper_work).work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 2 locks held by syz-executor3/536: #0: 000000007571bfe0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 #1: 00000000065cd332 (rcu_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:296 [inline] #1: 00000000065cd332 (rcu_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited.constprop.58+0x7c7/0x9d0 kernel/rcu/tree_exp.h:620 1 lock held by syz-executor4/552: #0: 00000000add7dc10 (&kvm->slots_lock){+.+.}, at: kvm_vm_ioctl_register_coalesced_mmio+0x1a7/0x4f0 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:155 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1019 Comm: khungtaskd Not tainted 4.20.0-rc7+ #376 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb51/0x1060 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: 1.163 msecs NMI backtrace for cpu 0 CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 4.20.0-rc7+ #376 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events rtc_timer_do_work RIP: 0010:mark_held_locks+0xc7/0x130 kernel/locking/lockdep.c:2737 Code: 03 83 e2 07 42 0f b6 04 38 38 d0 7f 04 84 c0 75 5e 0f b6 46 22 8b 55 d4 a8 03 0f 45 55 d0 a8 04 74 0c 4c 89 f7 e8 69 e2 ff ff <85> c0 74 1e 41 0f b6 45 00 83 c3 01 84 c0 74 04 3c 03 7e 40 41 39 RSP: 0018:ffff8881d9b1f0e8 EFLAGS: 00000082 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 1ffff1103b362579 RDX: 1ffffffff159fa9e RSI: 0000000000000000 RDI: ffffffff8acfd4f0 RBP: ffff8881d9b1f128 R08: ffff8881d9b12bc8 R09: 0000000000000006 R10: 0000000000000000 R11: ffff8881d9b12300 R12: ffff8881d9b12b80 R13: ffffed103b36256f R14: ffff8881d9b12300 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdecd2e3000 CR3: 00000001d881f000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __trace_hardirqs_on_caller kernel/locking/lockdep.c:2766 [inline] lockdep_hardirqs_on+0x3bb/0x5b0 kernel/locking/lockdep.c:2811 trace_hardirqs_on+0xbd/0x310 kernel/trace/trace_preemptirq.c:30 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x82/0xd0 kernel/locking/spinlock.c:184 spin_unlock_irqrestore include/linux/spinlock.h:384 [inline] __wake_up_common_lock+0x1d0/0x330 kernel/sched/wait.c:122 __wake_up+0xe/0x10 kernel/sched/wait.c:145 rtc_handle_legacy_irq+0x8f/0xd0 drivers/rtc/interface.c:609 rtc_uie_update_irq+0x1f/0x30 drivers/rtc/interface.c:636 rtc_timer_do_work+0x287/0x11b0 drivers/rtc/interface.c:915 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352