INFO: task kworker/0:7:5604 blocked for more than 143 seconds. Not tainted 5.6.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:7 D25912 5604 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:2664 usb_disable_device+0x23d/0x790 drivers/usb/core/message.c:1237 usb_disconnect+0x293/0x900 drivers/usb/core/hub.c:2207 hub_port_connect drivers/usb/core/hub.c:5042 [inline] hub_port_connect_change drivers/usb/core/hub.c:5331 [inline] port_event drivers/usb/core/hub.c:5477 [inline] hub_event+0x1a1d/0x4300 drivers/usb/core/hub.c:5559 process_one_work+0x94b/0x1620 kernel/workqueue.c:2264 process_scheduled_works kernel/workqueue.c:2326 [inline] worker_thread+0x7ab/0xe20 kernel/workqueue.c:2412 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: 1 lock held by khungtaskd/22: #0: ffffffff87109020 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:5331 2 locks held by rsyslogd/1677: #0: ffff8881cfdd2360 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821 #1: ffffffff870fdf18 (logbuf_lock){-.-.}, at: __debug_check_no_obj_freed lib/debugobjects.c:955 [inline] #1: ffffffff870fdf18 (logbuf_lock){-.-.}, at: debug_check_no_obj_freed+0xc4/0x445 lib/debugobjects.c:998 2 locks held by getty/1769: #0: ffff8881cea09090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004652e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1770: #0: ffff8881ce55a090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004852e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1771: #0: ffff8881ceb16090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004752e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1772: #0: ffff8881ce559090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004812e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1774: #0: ffff8881cecc9090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004552e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by kworker/u4:2/1802: #0: ffff8881da029928 ((wq_completion)events_unbound){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881da029928 ((wq_completion)events_unbound){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881da029928 ((wq_completion)events_unbound){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881da029928 ((wq_completion)events_unbound){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881da029928 ((wq_completion)events_unbound){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8881da029928 ((wq_completion)events_unbound){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8881da029928 ((wq_completion)events_unbound){+.+.}, at: process_one_work+0x82a/0x1620 kernel/workqueue.c:2235 #1: ffff8881d4827dd0 ((work_completion)(&sub_info->work)){+.+.}, at: process_one_work+0x85e/0x1620 kernel/workqueue.c:2239 4 locks held by kworker/0:11/5882: 2 locks held by getty/8633: #0: ffff8881d225a090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900114572e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 5 locks held by kworker/0:2/26770: 2 locks held by getty/5467: #0: ffff8881d475b090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900073332e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 5 locks held by kworker/0:7/5604: #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x82a/0x1620 kernel/workqueue.c:2235 #1: ffff8881b60d7dd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85e/0x1620 kernel/workqueue.c:2239 #2: ffff8881d4ca9200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #2: ffff8881d4ca9200 (&dev->mutex){....}, at: hub_event+0x1be/0x4300 drivers/usb/core/hub.c:5505 #3: ffff8881ac3a8200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #3: ffff8881ac3a8200 (&dev->mutex){....}, at: usb_disconnect+0x91/0x900 drivers/usb/core/hub.c:2198 #4: ffff8881ca239190 (&dev->mutex){....}, at: device_release_driver_internal+0x23/0x500 drivers/base/dd.c:1165 3 locks held by kworker/0:12/5608: #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8881d888d528 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x82a/0x1620 kernel/workqueue.c:2235 #1: ffffffff87109020 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:435 [inline] #1: ffffffff87109020 (rcu_read_lock){....}, at: update_curr+0x28a/0x830 kernel/sched/fair.c:859 #2: ffff8881d4d75290 (&(&dev->power.lock)->rlock){-.-.}, at: spin_lock_irq include/linux/spinlock.h:363 [inline] #2: ffff8881d4d75290 (&(&dev->power.lock)->rlock){-.-.}, at: __rpm_callback+0x188/0x3c0 drivers/base/power/runtime.c:380 1 lock held by syz-executor.1/7737: #0: ffff8881db234618 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1215 [inline] #0: ffff8881db234618 (&rq->lock){-.-.}, at: __schedule+0x21c/0x1d80 kernel/sched/core.c:4028 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 22 Comm: khungtaskd Not tainted 5.6.0-rc3-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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5608 Comm: kworker/0:12 Not tainted 5.6.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usb_hub_wq hub_event RIP: 0010:hub_port_connect drivers/usb/core/hub.c:5035 [inline] RIP: 0010:hub_port_connect_change drivers/usb/core/hub.c:5331 [inline] RIP: 0010:port_event drivers/usb/core/hub.c:5477 [inline] RIP: 0010:hub_event+0x191c/0x4300 drivers/usb/core/hub.c:5559 Code: fe 25 00 00 48 b9 00 00 00 00 00 fc ff df 48 8b 45 00 48 89 44 24 48 48 c1 e8 03 80 3c 08 00 0f 85 ce 25 00 00 48 8b 44 24 48 <48> 8b 28 48 85 ed 0f 84 f5 00 00 00 e8 53 32 df fd 48 8b 44 24 70 RSP: 0018:ffff8881d562fb10 EFLAGS: 00000246 RAX: ffff8881d4d51000 RBX: 0000000000000001 RCX: dffffc0000000000 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8881d4d514e0 RBP: ffff8881d50b3d98 R08: ffff8881d0494980 R09: ffffed103a9aa29d R10: ffffed103a9aa29c R11: ffff8881d4d514e7 R12: ffff8881d4d27000 R13: 0000000000000001 R14: ffff8881d4d51000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d527000 CR3: 00000001b9f8c000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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