INFO: task kworker/u4:0:7 blocked for more than 143 seconds. Not tainted 5.4.0-rc1+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:0 D27688 7 2 0x80004000 Workqueue: events_unbound fsnotify_connector_destroy_workfn Call Trace: context_switch kernel/sched/core.c:3384 [inline] __schedule+0x74b/0xb80 kernel/sched/core.c:4069 schedule+0x131/0x1e0 kernel/sched/core.c:4136 schedule_timeout+0x46/0x240 kernel/time/timer.c:1871 do_wait_for_common+0x2e7/0x4d0 kernel/sched/completion.c:83 __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x47/0x60 kernel/sched/completion.c:136 __synchronize_srcu+0x1d7/0x260 kernel/rcu/srcutree.c:921 synchronize_srcu+0x2cb/0x2f0 kernel/rcu/srcutree.c:999 fsnotify_connector_destroy_workfn+0x44/0xb0 fs/notify/mark.c:164 process_one_work+0x7ef/0x10e0 kernel/workqueue.c:2269 process_scheduled_works kernel/workqueue.c:2331 [inline] worker_thread+0xf27/0x1630 kernel/workqueue.c:2417 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 2 locks held by kworker/u4:0/7: #0: ffff8880aa4351a8 ((wq_completion)events_unbound){+.+.}, at: spin_unlock_irq include/linux/spinlock.h:388 [inline] #0: ffff8880aa4351a8 ((wq_completion)events_unbound){+.+.}, at: process_one_work+0x75d/0x10e0 kernel/workqueue.c:2242 #1: ffff8880a988fd78 (connector_reaper_work){+.+.}, at: process_one_work+0x79f/0x10e0 kernel/workqueue.c:2244 3 locks held by kworker/0:1/12: #0: ffff8880aa4278e8 ((wq_completion)events){+.+.}, at: spin_unlock_irq include/linux/spinlock.h:388 [inline] #0: ffff8880aa4278e8 ((wq_completion)events){+.+.}, at: process_one_work+0x75d/0x10e0 kernel/workqueue.c:2242 #1: ffff8880a98c7d78 ((work_completion)(&aux->work)){+.+.}, at: process_one_work+0x79f/0x10e0 kernel/workqueue.c:2244 #2: ffff8880aea34998 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1215 [inline] #2: ffff8880aea34998 (&rq->lock){-.-.}, at: __schedule+0xd6/0xb80 kernel/sched/core.c:4017 3 locks held by kworker/u4:1/21: 5 locks held by kworker/1:1/22: 2 locks held by kworker/u4:4/484: #0: ffff8880aa4351a8 ((wq_completion)events_unbound){+.+.}, at: spin_unlock_irq include/linux/spinlock.h:388 [inline] #0: ffff8880aa4351a8 ((wq_completion)events_unbound){+.+.}, at: process_one_work+0x75d/0x10e0 kernel/workqueue.c:2242 #1: ffff8880a8827d78 ((reaper_work).work){+.+.}, at: process_one_work+0x79f/0x10e0 kernel/workqueue.c:2244 1 lock held by khungtaskd/1071: #0: ffffffff888d3ec0 (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 2 locks held by kworker/1:2/3223: 3 locks held by udevd/3900: 1 lock held by rsyslogd/7772: #0: ffff888094817620 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x243/0x2e0 fs/file.c:801 2 locks held by getty/7863: #0: ffff8880a983cb50 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f112e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7864: #0: ffff888097bf2a90 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005efd2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7865: #0: ffff88809c7fced0 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f192e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7866: #0: ffff888097bf2210 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f012e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7867: #0: ffff888097bf3310 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005ef12e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7868: #0: ffff88809c586310 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f152e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7869: #0: ffff88809adef1d0 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005ee12e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.4/13586: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1071 Comm: khungtaskd Not tainted 5.4.0-rc1+ #0 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+0x1d8/0x2f8 lib/dump_stack.c:113 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace+0x17/0x20 include/linux/nmi.h:146 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xbb9/0xbd0 kernel/hung_task.c:289 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 13578 Comm: syz-executor.2 Not tainted 5.4.0-rc1+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:199 [inline] RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:2862 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:2881 [inline] RIP: 0010:validate_chain+0x143/0x7bc0 kernel/locking/lockdep.c:2936 Code: 73 66 0f 1f 44 00 00 4c 8d 6b 18 4c 89 e8 48 c1 e8 03 80 3c 10 00 74 12 4c 89 ef e8 a7 28 53 00 48 ba 00 00 00 00 00 fc ff df <49> 8b 45 00 4c 39 f0 74 38 48 83 c3 08 48 89 d8 48 c1 e8 03 80 3c RSP: 0018:ffff8880aeb099b0 EFLAGS: 00000046 RAX: 1ffffffff11f5a09 RBX: ffffffff88fad030 RCX: ffffffff815944d2 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff895de4e0 RBP: ffff8880aeb09bb0 R08: dffffc0000000000 R09: fffffbfff12bbc9d R10: fffffbfff12bbc9d R11: 0000000000000000 R12: ffff8880942e2a78 R13: ffffffff88fad048 R14: fc64caf83017ef16 R15: ffff8880942e21c0 FS: 00007f9280df7700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000738000 CR3: 0000000075ad8000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0xc75/0x1be0 kernel/locking/lockdep.c:3955 lock_acquire+0x158/0x250 kernel/locking/lockdep.c:4487 seqcount_lockdep_reader_access include/linux/seqlock.h:81 [inline] read_seqcount_begin+0xaf/0x1c0 include/linux/seqlock.h:164 ktime_get+0x4a/0x110 kernel/time/timekeeping.c:757 clockevents_program_event+0xde/0x2d0 kernel/time/clockevents.c:326 tick_program_event+0x9e/0x120 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x980/0xda0 kernel/time/hrtimer.c:1651 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:830 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:756 [inline] RIP: 0010:console_trylock_spinning+0x31f/0x390 kernel/printk/printk.c:1751 Code: c1 e8 03 42 80 3c 38 00 74 0c 48 c7 c7 70 91 8a 88 e8 b5 e6 4f 00 48 83 3d fd 09 2e 07 00 74 69 e8 66 b2 16 00 4c 89 f7 57 9d <0f> 1f 44 00 00 bb 01 00 00 00 48 c7 c7 d8 25 8d 88 31 f6 ba 01 00 RSP: 0018:ffff88807671fab0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: ffffffff815c877a RBX: 0000000000000001 RCX: ffff8880942e21c0 RDX: 0000000000000000 RSI: ffffffff815c82dc RDI: 0000000000000286 RBP: ffff88807671fad0 R08: ffff8880942e2a18 R09: fffffbfff117cbfd R10: fffffbfff117cbfd R11: 0000000000000000 R12: 00000000ffffff00 R13: 000000000000f0aa R14: 0000000000000286 R15: dffffc0000000000 vprintk_emit+0x21c/0x3a0 kernel/printk/printk.c:1995 vprintk_default+0x28/0x30 kernel/printk/printk.c:2023 vprintk_func+0x158/0x170 kernel/printk/printk_safe.c:386 printk+0x62/0x8d kernel/printk/printk.c:2056 bpf_prog_alloc_no_stats+0x252/0x2c0 kernel/bpf/core.c:101 bpf_prog_alloc+0x21/0x160 kernel/bpf/core.c:111 bpf_prog_load kernel/bpf/syscall.c:1663 [inline] __do_sys_bpf+0x514a/0xbf90 kernel/bpf/syscall.c:2867 __se_sys_bpf kernel/bpf/syscall.c:2826 [inline] __x64_sys_bpf+0x7a/0x90 kernel/bpf/syscall.c:2826 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459a59 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:00007f9280df6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459a59 RDX: 0000000000000070 RSI: 0000000020000440 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9280df76d4 R13: 00000000004bfef0 R14: 00000000004d20f0 R15: 00000000ffffffff