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:21576 pid:23    tgid:23    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x145d/0x4a00 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 rwsem_down_write_slowpath+0x521/0x1310 kernel/locking/rwsem.c:1185
 __down_write_common kernel/locking/rwsem.c:1317 [inline]
 __down_write kernel/locking/rwsem.c:1326 [inline]
 down_write+0x1d6/0x200 kernel/locking/rwsem.c:1591
 kernfs_add_one+0x38/0x840 fs/kernfs/dir.c:796
 kernfs_create_dir_ns+0xfc/0x1a0 fs/kernfs/dir.c:1098
 sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:73 [inline]
 kobject_add_internal+0x2c4/0x9d0 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_add+0x16e/0x240 lib/kobject.c:426
 device_add+0x288/0x1980 drivers/base/core.c:3627
 usb_new_device+0xd07/0x1a90 drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x31bf/0x5420 drivers/usb/core/hub.c:5953
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/0:1/10:
 #0: 
ffff888102a90d48
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: 
ffffc900000afca0 (
(work_completion)(&(&d->rc_query_work)->work)
){+.+.}-{0:0}
, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: ffffffff892bb140
 (console_lock){+.+.}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:2037 [inline]
 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0x56d/0x6b0 kernel/printk/printk.c:2425
 #3: 
ffffffff93c04018 (
&obj_hash[i].lock
){-.-.}-{2:2}
, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline]
, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline]
, at: console_flush_one_record+0x103/0xc60 kernel/printk/printk.c:3192
 #4: 
ffffffff891dad00
 (console_owner
){..-.}-{0:0}
, at: raw_spin_rq_lock_nested kernel/sched/core.c:639 [inline]
, at: raw_spin_rq_lock kernel/sched/sched.h:1558 [inline]
, at: rq_lock kernel/sched/sched.h:1885 [inline]
, at: ttwu_queue kernel/sched/core.c:3892 [inline]
, at: try_to_wake_up+0x679/0x1480 kernel/sched/core.c:4218
5 locks held by kworker/1:0/23:
 #0: ffff888102a90d48
 (
(wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: 
ffffc9000018fca0 (
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: ffff88810a32b198
 (
&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899
 #3: ffff88811b6ee198
 (
&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006
 #4: 
ffff888100ac5988
 (&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x3d/0x100 fs/kernfs/dir.c:1717
1 lock held by khungtaskd/30:
 #0: ffffffff892cd760
 (
rcu_read_lock){....}-{1:3}
, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:1/32:
 #0: 
ffff8881f56390d8
 (
&rq->__lock){-.-.}-{2:2}
, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc90000227ca0
 (
(work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
4 locks held by kworker/1:1/42:
 #0: ffff888100071948
 (
(wq_completion)events
){+.+.}-{0:0}
, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: 
ffffc900004d7ca0 (kernfs_notify_work){+.+.}-{0:0}
, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: ffff888100ac5ab8 (&root->kernfs_supers_rwsem
){++++}-{4:4}
, at: kernfs_notify_workfn+0xf7/0xb30 fs/kernfs/file.c:932
 #3: 
ffff888100ac5988
 (
&root->kernfs_rwsem){++++}-{4:4}
, at: kernfs_notify_workfn+0xff/0xb30 fs/kernfs/file.c:933
2 locks held by kworker/u8:12/2482:
 #0: 
ffff888100089148 ((wq_completion)events_unbound
#2
){+.+.}-{0:0}, at: raw_spin_rq_lock_nested kernel/sched/core.c:639 [inline]
){+.+.}-{0:0}, at: raw_spin_rq_lock kernel/sched/sched.h:1558 [inline]
){+.+.}-{0:0}, at: rq_lock kernel/sched/sched.h:1885 [inline]
){+.+.}-{0:0}, at: __schedule+0x332/0x4a00 kernel/sched/core.c:6768
 #1: 
ffffc90003c8fca0 (
(work_completion)(&sub_info->work)
){+.+.}-{0:0}
, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
2 locks held by getty/2922:
 #0: 
ffff888112c5f0a0
 (
&tty->ldisc_sem){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: 
ffffc900000452f0
 (&ldata->atomic_read_lock
){+.+.}-{4:4}
, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/2968:
 #0: ffffffff892d8eb8
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by syz-executor/2970:
 #0: 
ffffffff892d8eb8
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
4 locks held by kworker/1:3/5220:
7 locks held by kworker/0:5/5268:
 #0: 
ffff888102a90d48
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: 
ffffc9000240fca0
 (
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: 
ffff88810a7ab198
 (
&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899
 #3: ffff88813898b198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: usb_disconnect+0x10a/0x9e0 drivers/usb/core/hub.c:2336
 #4: ffff888113d9e160
 (&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: __device_driver_lock drivers/base/dd.c:1104 [inline]
, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1302
 #5: ffffffff8a086808
 (
input_mutex
){+.+.}-{4:4}
, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
, at: __input_unregister_device+0x184/0x4d0 drivers/input/input.c:2187
 #6: 
ffff888100ac5988
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x3d/0x100 fs/kernfs/dir.c:1717
1 lock held by udevd/5306:
 #0: ffff888100ac5988
 (
&root->kernfs_rwsem){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
1 lock held by udevd/5478:
 #0: 
ffff888100ac5988
 (
&root->kernfs_rwsem){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
1 lock held by udevd/6460:
 #0: 
ffff888100ac5988
 (&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
1 lock held by syz.2.1571/11036:
 #0: ffff888100ac5988
 (
&root->kernfs_rwsem){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x3d/0x100 fs/kernfs/dir.c:1717
1 lock held by syz.1.1572/11040:
 #0: 
ffff888100ac5988 (&root->kernfs_rwsem){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x3d/0x100 fs/kernfs/dir.c:1717
1 lock held by syz.0.1573/11039:
 #0: 
ffff888100ac5988
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x3d/0x100 fs/kernfs/dir.c:1717
1 lock held by syz.3.1574/11042:
 #0: ffff888100ac5988
 (
&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_activate fs/kernfs/dir.c:1430 [inline]
&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x349/0x840 fs/kernfs/dir.c:839
1 lock held by syz.3.1574/11044:
 #0: ffff888100ac5988
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_activate fs/kernfs/dir.c:1430 [inline]
, at: kernfs_add_one+0x349/0x840 fs/kernfs/dir.c:839
1 lock held by syz.4.1575/11046:
 #0: 
ffff888100ac5988
 (&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_activate fs/kernfs/dir.c:1430 [inline]
, at: kernfs_add_one+0x349/0x840 fs/kernfs/dir.c:839
1 lock held by syz-executor/11048:
 #0: ffff888100ac5988
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
1 lock held by syz-executor/11049:
 #0: ffff888100ac5988
 (&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
1 lock held by syz-executor/11050:
 #0: ffff888100ac5988
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
1 lock held by modprobe/11197:
1 lock held by modprobe/11198:
 #0: 
ffff8881f56390d8
 (
&rq->__lock){-.-.}-{2:2}
, at: raw_spin_rq_lock_nested kernel/sched/core.c:639 [inline]
, at: raw_spin_rq_lock kernel/sched/sched.h:1558 [inline]
, at: rq_lock kernel/sched/sched.h:1885 [inline]
, at: __schedule+0x332/0x4a00 kernel/sched/core.c:6768
1 lock held by modprobe/11203:
1 lock held by modprobe/11204:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x133/0x180 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xe66/0x1180 kernel/hung_task.c:515
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events dvb_usb_read_remote_control
RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:407
Code: 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d c3 cc cc cc cc e8 11 4d fd fe eb a0 e8 9a 4d fd
RSP: 0018:ffffc900000af6e8 EFLAGS: 00000002
RAX: 0000000000000037 RBX: 00000000000003f8 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: ffffffff82e472f5 RDI: ffffffff93c8af80
RBP: ffffffff93c8af40 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: ffff888101ab27e8 R12: 0000000000000000
R13: 0000000000000037 R14: ffffffff93c8af40 R15: ffffffff82e47290
FS:  0000000000000000(0000) GS:ffff888268bf4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc695e10e9c CR3: 00000000090a6000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 serial_port_out include/linux/serial_core.h:811 [inline]
 serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3264 [inline]
 serial8250_console_write+0xfbd/0x1890 drivers/tty/serial/8250/8250_port.c:3342
 console_emit_next_record kernel/printk/printk.c:3129 [inline]
 console_flush_one_record+0x796/0xc60 kernel/printk/printk.c:3215
 console_flush_all kernel/printk/printk.c:3289 [inline]
 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
 console_unlock+0xef/0x240 kernel/printk/printk.c:3359
 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426
 _printk+0xc7/0x100 kernel/printk/printk.c:2451
 m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline]
 m920x_rc_core_query+0x2d7/0x500 drivers/media/usb/dvb-usb/m920x.c:229
 dvb_usb_read_remote_control+0xdd/0x1c0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>