INFO: task kworker/1:0:23 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0     state:D stack:20712 pid:23    tgid:23    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient hub_init_func3
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x1325/0x47d0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7326
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821
 device_lock include/linux/device.h:1102 [inline]
 hub_activate+0xe7c/0x1d50 drivers/usb/core/hub.c:1091
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/9:
 #0: 
ffff88810006b140
 (
(wq_completion)events
){+.+.}-{0:0}
, at: raw_spin_rq_lock_nested kernel/sched/core.c:667 [inline]
, at: raw_spin_rq_lock kernel/sched/sched.h:1653 [inline]
, at: rq_lock kernel/sched/sched.h:1991 [inline]
, at: __schedule+0x2dc/0x47d0 kernel/sched/core.c:7108
 #1: 
ffffc9000009fd18
 (
free_ipc_work
){+.+.}-{0:0}
, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
 #2: 
ffffffff898a1e80
 (
vmap_purge_lock
){+.+.}-{4:4}
, at: drain_vmap_area_work+0x17/0x40 mm/vmalloc.c:2429
3 locks held by kworker/1:0/23:
 #0: ffff888100069d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
 #1: ffffc9000018fd18 ((work_completion)(&(&hub->init_work)->work)#2){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
 #2: ffff88812d6981d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
 #2: ffff88812d6981d8 (&dev->mutex){....}-{4:4}, at: hub_activate+0xe7c/0x1d50 drivers/usb/core/hub.c:1091
5 locks held by kworker/1:1/28:
1 lock held by khungtaskd/30:
 #0: 
ffffffff896e3000
 (
rcu_read_lock
){....}-{1:3}
, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:2/37:
 #0: 
ffff888100e98940
 (
(wq_completion)netns
){+.+.}-{0:0}
, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
 #1: 
ffffc90000277d18
 (
net_cleanup_work
){+.+.}-{0:0}
, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
 #2: 
ffffffff8ab090e8
 (
pernet_ops_rwsem
){++++}-{4:4}
, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
 #3: 
ffffffff896eeaa8
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
8 locks held by kworker/1:2/1122:
1 lock held by udevd/2855:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1217
2 locks held by getty/2917:
 #0: 
ffff888114d3a0a0
 (
&tty->ldisc_sem
){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: 
ffffc900000452e8
 (
&ldata->atomic_read_lock
){+.+.}-{4:4}
, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
1 lock held by udevd/7440:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1217
5 locks held by kworker/0:3/7451:
 #0: 
ffff8881066b4140
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
 #1: 
ffffc90001f6fd18
 (
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
 #2: 
ffff88810b7561d8
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:1102 [inline]
, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
 #3: 
ffff888100e87aa0
 (
&root->kernfs_supers_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x49/0x120 fs/kernfs/dir.c:1791
 #4: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x51/0x120 fs/kernfs/dir.c:1792
6 locks held by kworker/1:3/7468:
 #0: 
ffff8881066b4140
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
 #1: 
ffffc90002befd18
 (
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
 #2: 
ffff88810b7ae1d8
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:1102 [inline]
, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
 #3: 
ffff888105295268
 (
&(&priv->bus_notifier)->rwsem
){++++}-{4:4}
, at: blocking_notifier_call_chain kernel/notifier.c:379 [inline]
, at: blocking_notifier_call_chain+0x53/0xa0 kernel/notifier.c:368
 #4: 
ffff888100e87aa0
 (
&root->kernfs_supers_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x49/0x120 fs/kernfs/dir.c:1791
 #5: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x51/0x120 fs/kernfs/dir.c:1792
4 locks held by udevd/7469:
 #0: 
ffff8881359b5bd8
 (
&p->lock
){+.+.}-{4:4}
, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
 #1: 
ffff888134e20c80
 (
&of->mutex
#2
){+.+.}-{4:4}
, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:165
 #2: 
ffff8881208e8b48
 (
kn->active
#20
){++++}-{0:0}
, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:166
 #3: 
ffff8881133971d8
 (
&dev->mutex
){....}-{4:4}
, at: device_lock_interruptible include/linux/device.h:1107 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
10 locks held by kworker/1:4/7483:
2 locks held by kworker/1:5/7517:
1 lock held by udevd/7518:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1217
1 lock held by udevd/7527:
 #0: ffff888100e87980 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1217
1 lock held by udevd/8220:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1217
1 lock held by syz.0.393/8846:
 #0: 
ffffffff896eeaa8
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by syz.4.395/8855:
1 lock held by fido_id/8866:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1217
2 locks held by syz-executor/8872:
 #0: 
ffff8881f56397a0
 (
&rq->__lock
){-.-.}-{2:2}
, at: raw_spin_rq_lock_nested kernel/sched/core.c:667 [inline]
, at: raw_spin_rq_lock kernel/sched/sched.h:1653 [inline]
, at: rq_lock kernel/sched/sched.h:1991 [inline]
, at: __schedule+0x2dc/0x47d0 kernel/sched/core.c:7108
 #1: 
ffff8881221b2518 (&sighand->siglock){....}-{3:3}, at: do_notify_parent+0x78c/0x10b0 kernel/signal.c:2230
1 lock held by syz-executor/8874:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1217
1 lock held by syz-executor/8875:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1217

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122
 nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
cdc_wdm 1-1:1.0: Stall on int endpoint
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 1122 Comm: kworker/1:2 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_power_efficient gc_worker
RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x10/0x20 kernel/kcov.c:300
Code: ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 <bf> 01 00 00 00 e9 86 fe ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90
RSP: 0018:ffffc900001a7fe8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff878ae146 RCX: ffffffff87775c39
RDX: 0000000000000025 RSI: 0000000000000025 RDI: 0000000000000025
RBP: ffffc900001a8090 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000025 R11: 00000000001c32d8 R12: 0000000000000025
R13: ffffffff878ae145 R14: ffffc900001a8120 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888268740000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff19b83d080 CR3: 00000000094ac000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 format_decode+0x189/0xdd0 lib/vsprintf.c:2709
 vsnprintf+0x1c0/0x1300 lib/vsprintf.c:2887
 sprintf+0xcc/0x100 lib/vsprintf.c:3112
 print_time kernel/printk/printk.c:1359 [inline]
 info_print_prefix+0x25a/0x350 kernel/printk/printk.c:1385
 record_print_text+0x143/0x3c0 kernel/printk/printk.c:1434
 printk_get_next_message+0x2d1/0x6c0 kernel/printk/printk.c:3072
 console_emit_next_record kernel/printk/printk.c:3137 [inline]
 console_flush_one_record+0x67c/0xe50 kernel/printk/printk.c:3269
 console_flush_all kernel/printk/printk.c:3343 [inline]
 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
 console_unlock+0x103/0x260 kernel/printk/printk.c:3413
 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2479
 dev_vprintk_emit+0x391/0x3e0 drivers/base/core.c:4996
 dev_printk_emit+0xd2/0x10d drivers/base/core.c:5007
 __dev_printk+0xcb/0x100 drivers/base/core.c:5019
 _dev_err+0xef/0x127 drivers/base/core.c:5062
 wdm_int_callback+0x981/0xa80 drivers/usb/class/cdc-wdm.c:271
 __usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657
 usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
 dummy_timer+0xda1/0x36c0 drivers/usb/gadget/udc/dummy_hcd.c:2005
 __run_hrtimer kernel/time/hrtimer.c:2032 [inline]
 __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096
 hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2113
 handle_softirqs+0x1dd/0x990 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x160/0x210 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data+0x0/0x90 kernel/kcov.c:246
Code: e9 4e fe ff ff 48 8b 7c 24 08 e8 8b 62 68 00 e9 6d fd ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <65> 8b 05 b9 fd 49 0b 49 89 f8 49 89 f1 49 89 d2 65 48 8b 3d 90 fd
RSP: 0018:ffffc90002effb50 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff8688776b
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 000000000005fc93 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000040000 R15: 000000000002fe49
 rcu_read_unlock include/linux/rcupdate.h:869 [inline]
 gc_worker+0xc3b/0x1a30 net/netfilter/nf_conntrack_core.c:1609
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Cannot schedule work
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint
cdc_wdm 1-1:1.0: Stall on int endpoint