INFO: task kworker/u4:1:4744 blocked for more than 143 seconds. Not tainted 5.2.0-rc3+ #43 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:1 D25904 4744 2 0x80004000 Workqueue: events_unbound fsnotify_connector_destroy_workfn Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x7cb/0x1560 kernel/sched/core.c:3445 schedule+0xa8/0x260 kernel/sched/core.c:3509 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1783 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+0x29c/0x440 kernel/sched/completion.c:136 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921 synchronize_srcu+0x2dc/0x3e8 kernel/rcu/srcutree.c:999 fsnotify_connector_destroy_workfn+0x4e/0xa0 fs/notify/mark.c:164 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/u4:3:14865 blocked for more than 144 seconds. Not tainted 5.2.0-rc3+ #43 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:3 D25904 14865 2 0x80004000 Workqueue: events_unbound fsnotify_mark_destroy_workfn Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x7cb/0x1560 kernel/sched/core.c:3445 schedule+0xa8/0x260 kernel/sched/core.c:3509 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1783 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+0x29c/0x440 kernel/sched/completion.c:136 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921 synchronize_srcu+0x2dc/0x3e8 kernel/rcu/srcutree.c:999 fsnotify_mark_destroy_workfn+0x110/0x3b0 fs/notify/mark.c:819 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 process_scheduled_works kernel/workqueue.c:2331 [inline] worker_thread+0x7be/0xe40 kernel/workqueue.c:2417 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 1 lock held by khungtaskd/1045: #0: 000000006321563c (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5149 3 locks held by udevd/3880: 1 lock held by rsyslogd/8674: #0: 00000000c2d7ad6e (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8764: #0: 000000003c404091 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b8b661df (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8765: #0: 0000000084769870 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000058df2379 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8766: #0: 0000000038fb5c9b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f826938c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8767: #0: 000000007d362aa2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000001065a219 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8768: #0: 000000005b6c4327 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000000a45d3f5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8769: #0: 0000000000986f7e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000000ee2cacf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8770: #0: 0000000016261ebf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000ef62a6c7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.3/8811: 2 locks held by kworker/u4:1/4744: #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: __write_once_size include/linux/compiler.h:221 [inline] #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2240 #1: 0000000096d729ad (connector_reaper_work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2244 2 locks held by kworker/u4:3/14865: #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: __write_once_size include/linux/compiler.h:221 [inline] #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: 000000001277f44a ((wq_completion)events_unbound){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2240 #1: 0000000003f56933 ((reaper_work).work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2244 1 lock held by syz-executor.3/14237: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1045 Comm: khungtaskd Not tainted 5.2.0-rc3+ #43 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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+0x9b7/0xec0 kernel/hung_task.c:289 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 14242 Comm: syz-executor.1 Not tainted 5.2.0-rc3+ #43 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:smp_apic_timer_interrupt+0x6/0x550 arch/x86/kernel/apic/apic.c:1053 Code: c7 28 11 7d 89 e8 ca 09 89 fa e9 5f fe ff ff 4c 89 e7 e8 bd 09 89 fa e9 f2 fc ff ff 90 90 90 90 90 90 90 90 55 48 89 e5 41 56 <41> 55 41 54 53 48 83 ec 08 65 4c 8b 25 a1 b0 e1 78 65 48 89 3d 99 RSP: 0018:ffff8880ae809fe0 EFLAGS: 00000096 RAX: 1ffffffff1164e7e RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8720150a RDI: ffff8880442bf978 RBP: ffff8880ae809fe8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f4dcf5ec700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31f24000 CR3: 000000005aba4000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:767 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x95/0xe0 kernel/locking/spinlock.c:191 Code: 48 c7 c0 f0 73 b2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 39 48 83 3d 62 b4 95 01 00 74 24 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 8c bc 30 fa 65 8b 05 dd 3d e5 78 RSP: 0018:ffff8880442bfa20 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff1164e7e RBX: 0000000000000286 RCX: 1ffff1100ae3c5f4 RDX: dffffc0000000000 RSI: ffff8880571e2f80 RDI: 0000000000000286 RBP: ffff8880442bfa30 R08: ffff8880571e2700 R09: ffff8880571e2fa0 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809f544018 R13: ffff88805f60b518 R14: 0000000000000286 R15: ffff88809f544018 spin_unlock_irqrestore include/linux/spinlock.h:393 [inline] snd_seq_prioq_cell_out+0x1e3/0x350 sound/core/seq/seq_prioq.c:238 snd_seq_check_queue.part.0+0x11e/0x360 sound/core/seq/seq_queue.c:258 snd_seq_check_queue sound/core/seq/seq_queue.c:242 [inline] snd_seq_enqueue_event+0x1fb/0x4d0 sound/core/seq/seq_queue.c:330 snd_seq_client_enqueue_event.constprop.0+0x259/0x470 sound/core/seq/seq_clientmgr.c:974 snd_seq_kernel_client_enqueue sound/core/seq/seq_clientmgr.c:2274 [inline] snd_seq_kernel_client_enqueue+0x19f/0x1f0 sound/core/seq/seq_clientmgr.c:2246 insert_queue sound/core/seq/oss/seq_oss_rw.c:173 [inline] snd_seq_oss_write+0x675/0x890 sound/core/seq/oss/seq_oss_rw.c:135 odev_write+0x5a/0x90 sound/core/seq/oss/seq_oss.c:164 __vfs_write+0x8a/0x110 fs/read_write.c:494 vfs_write+0x20c/0x580 fs/read_write.c:558 ksys_write+0x14f/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459279 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f4dcf5ebc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459279 RDX: 000000000000045c RSI: 0000000020000c80 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4dcf5ec6d4 R13: 00000000004c9316 R14: 00000000004e0350 R15: 00000000ffffffff