INFO: task kworker/1:5:4568 blocked for more than 143 seconds. Not tainted 5.6.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:5 D22928 4568 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0xcd/0x2b0 kernel/sched/core.c:4154 schedule_timeout+0x682/0xb20 kernel/time/timer.c:1871 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+0x26f/0x3c0 kernel/sched/completion.c:136 kthread_stop+0x17a/0x780 kernel/kthread.c:559 hwrng_unregister+0x24f/0x330 drivers/char/hw_random/core.c:556 chaoskey_disconnect+0x216/0x290 drivers/usb/misc/chaoskey.c:232 usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:436 __device_release_driver drivers/base/dd.c:1137 [inline] device_release_driver_internal+0x42f/0x500 drivers/base/dd.c:1168 bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533 device_del+0x481/0xd30 drivers/base/core.c:2677 usb_disable_device+0x23d/0x790 drivers/usb/core/message.c:1237 usb_disconnect+0x293/0x900 drivers/usb/core/hub.c:2211 hub_port_connect drivers/usb/core/hub.c:5046 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x1a1d/0x4300 drivers/usb/core/hub.c:5563 process_one_work+0x94b/0x1620 kernel/workqueue.c:2264 worker_thread+0x96/0xe20 kernel/workqueue.c:2410 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 5 locks held by kworker/0:1/12: 1 lock held by khungtaskd/23: #0: ffffffff87109060 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:5331 1 lock held by rsyslogd/1677: #0: ffff8881d01de0e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821 2 locks held by getty/1768: #0: ffff8881cead3090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900008372e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1769: #0: ffff8881ce5b1090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000085f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1770: #0: ffff8881ce491090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000083f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1771: #0: ffff8881cec92090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000084f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1772: #0: ffff8881ce403090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000085b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1773: #0: ffff8881ce8c3090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900008272e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 5 locks held by kworker/1:5/4568: #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x82a/0x1620 kernel/workqueue.c:2235 #1: ffff8881cc76fdd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85e/0x1620 kernel/workqueue.c:2239 #2: ffff8881d486f200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #2: ffff8881d486f200 (&dev->mutex){....}, at: hub_event+0x1be/0x4300 drivers/usb/core/hub.c:5509 #3: ffff8881ac1c1200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #3: ffff8881ac1c1200 (&dev->mutex){....}, at: usb_disconnect+0x91/0x900 drivers/usb/core/hub.c:2202 #4: ffff8881c0a0b190 (&dev->mutex){....}, at: device_release_driver_internal+0x23/0x500 drivers/base/dd.c:1165 5 locks held by kworker/1:7/4734: #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8881d8806528 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x82a/0x1620 kernel/workqueue.c:2235 #1: ffff8881d782fdd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85e/0x1620 kernel/workqueue.c:2239 #2: ffff8881d4982200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #2: ffff8881d4982200 (&dev->mutex){....}, at: hub_event+0x1be/0x4300 drivers/usb/core/hub.c:5509 #3: ffff8881ce402200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #3: ffff8881ce402200 (&dev->mutex){....}, at: __device_attach+0x7b/0x390 drivers/base/dd.c:874 #4: ffff8881ab70a190 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #4: ffff8881ab70a190 (&dev->mutex){....}, at: __device_attach+0x7b/0x390 drivers/base/dd.c:874 2 locks held by syz-executor.4/5837: #0: ffff8881d2812148 (&evdev->mutex){+.+.}, at: evdev_close_device drivers/input/evdev.c:425 [inline] #0: ffff8881d2812148 (&evdev->mutex){+.+.}, at: evdev_release+0xeb/0x1c0 drivers/input/evdev.c:466 #1: ffff8881c08222a8 (&dev->mutex#2){+.+.}, at: input_close_device+0x42/0x1a0 drivers/input/input.c:673 2 locks held by getty/5915: #0: ffff8881d2989090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000f9052e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 5.6.0-rc5-syzkaller #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+0xef/0x16e lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1db/0x207 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa99/0xfd0 kernel/hung_task.c:289 kthread+0x318/0x420 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: 1817 Comm: syz-executor.0 Not tainted 5.6.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_release kernel/locking/lockdep.c:4268 [inline] RIP: 0010:lock_release+0x288/0x6d0 kernel/locking/lockdep.c:4502 Code: 03 0f b6 14 11 84 d2 74 09 80 fa 03 0f 8e 54 03 00 00 66 83 68 22 10 66 f7 40 22 f0 ff 0f 85 06 01 00 00 4c 89 ee 8b 54 24 58 <48> b9 00 00 00 00 00 fc ff df 48 c1 ee 03 0f b6 0c 0e 84 c9 74 09 RSP: 0018:ffff8881db309c58 EFLAGS: 00000046 RAX: ffff8881d0276aa0 RBX: 1ffff1103b66138e RCX: 0000000000000000 RDX: 0000000000000002 RSI: ffff8881d0276a48 RDI: ffff8881d0276ac2 RBP: ffff8881db334658 R08: 0000000000000000 R09: fffffbfff0fcc0f9 R10: fffffbfff0fcc0f8 R11: ffffffff87e607c7 R12: ffffffff811ee03a R13: ffff8881d0276a48 R14: ffff8881d0276200 R15: 0000000000000003 FS: 00000000013b2940(0000) GS:ffff8881db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f73d0780000 CR3: 00000001b5e01000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock+0x12/0x30 kernel/locking/spinlock.c:183 rq_unlock kernel/sched/sched.h:1248 [inline] ttwu_queue kernel/sched/core.c:2406 [inline] try_to_wake_up+0xa9a/0x1690 kernel/sched/core.c:2639 hrtimer_wakeup+0x43/0x60 kernel/time/hrtimer.c:1769 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x32c/0xd20 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x2e8/0x730 kernel/time/hrtimer.c:1641 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline] smp_apic_timer_interrupt+0xfe/0x540 arch/x86/kernel/apic/apic.c:1144 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:lock_acquire+0x173/0x340 kernel/locking/lockdep.c:4488 Code: c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 ac 01 00 00 c7 83 4c 08 00 00 00 00 00 00 ff 34 24 9d <48> 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 65 8b 15 27 72 db 7e RSP: 0018:ffff8881b5f5fbc0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000007 RBX: ffff8881d0276200 RCX: 00000000000045a3 RDX: 0000000000000000 RSI: 1ffff11036bebf61 RDI: ffff8881d0276a4c RBP: ffffffff870090d8 R08: ffffffff8930e098 R09: fffffbfff1266e87 R10: fffffbfff1266e86 R11: ffffffff89337437 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000000 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x2a/0x40 kernel/locking/spinlock.c:223 do_wait+0x3b9/0x9c0 kernel/exit.c:1442 kernel_wait4+0x14c/0x260 kernel/exit.c:1617 __do_sys_wait4+0x147/0x160 kernel/exit.c:1629 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x41668a Code: 0f 83 6a 18 00 00 c3 66 0f 1f 84 00 00 00 00 00 8b 05 0e 1e 87 00 85 c0 75 36 45 31 d2 48 63 d2 48 63 ff b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 d4 ff ff ff f7 RSP: 002b:00007ffc11218508 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: ffffffffffffffda RBX: 000000000005a6a7 RCX: 000000000041668a RDX: 0000000040000001 RSI: 00007ffc11218540 RDI: ffffffffffffffff RBP: 0000000000000126 R08: 0000000000000001 R09: 00000000013b2940 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc11218540 R14: 000000000005a6a7 R15: 00007ffc11218550