INFO: task kworker/u8:5:11540 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:5    state:D
 stack:27240 pid:11540 tgid:11540 ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_unbound idle_cull_fn

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x12fc/0x3b80 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7026
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
 idle_cull_fn+0x99/0x460 kernel/workqueue.c:2960
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x56d/0x700 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/0:1/10:
 #0: 
ffff888106efe948
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
 #1: 
ffffc900000afd10
 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
 #2: 
ffff88810b7d0198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:914 [inline]
, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5899
1 lock held by khungtaskd/30:
 #0: 
ffffffff892c89e0
 (
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 getty/2915:
 #0: 
ffff8881083170a0
 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: 
ffffc900000432f0
 (
&ldata->atomic_read_lock
){+.+.}-{4:4}
, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
7 locks held by kworker/0:4/5260:
6 locks held by kworker/0:5/5379:
 #0: 
ffff888106efe948
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
 #1: 
ffffc9000216fd10
 (
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
 #2: 
ffff88810b7e8198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:914 [inline]
, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5899
 #3: 
ffff88813627d198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:914 [inline]
, at: usb_disconnect+0x10a/0x9c0 drivers/usb/core/hub.c:2336
 #4: 
ffff88811d344160 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:914 [inline]
, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1294
 #5: 
ffffffff8a058468
 (
input_mutex
){+.+.}-{4:4}
, at: class_mutex_constructor include/linux/mutex.h:228 [inline]
, at: __input_unregister_device+0x184/0x4d0 drivers/input/input.c:2187
3 locks held by kworker/0:6/5710:
 #0: 
ffff888100071948
 (
(wq_completion)events
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
 #1: 
ffffc9001210fd10
 (
free_ipc_work
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
 #2: 
ffffffff892d3f78
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
5 locks held by kworker/u8:4/11519:
 #0: 
ffff888100ac4948
 (
(wq_completion)netns
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
 #1: 
ffffc90015087d10
 (
net_cleanup_work
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
 #2: 
ffffffff8a61b6f0
 (
pernet_ops_rwsem
){++++}-{4:4}
, at: cleanup_net+0xad/0x8b0 net/core/net_namespace.c:669
 #3: ffffffff8a631a48
 (
rtnl_mutex
){+.+.}-{4:4}
, at: default_device_exit_batch+0x8b/0xaf0 net/core/dev.c:12837
 #4: 
ffffffff892d3f78
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by syz-executor/13253:
 #0: 
ffffffff8a631a48
 (
rtnl_mutex){+.+.}-{4:4}
, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
, at: rtnl_newlink+0x600/0x1e90 net/core/rtnetlink.c:4064
1 lock held by syz-executor/13278:
 #0: 
ffffffff8a631a48
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: inet6_rtm_newaddr+0x4e4/0x19e0 net/ipv6/addrconf.c:5027
1 lock held by syz-executor/13392:
 #0: 
ffffffff8a631a48
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978
1 lock held by syz-executor/14044:
 #0: 
ffffffff8a631a48
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: inet6_rtm_newaddr+0x4e4/0x19e0 net/ipv6/addrconf.c:5027
1 lock held by syz-executor/14517:
 #0: 
ffffffff8a631a48
 (rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
, at: rtnl_newlink+0x600/0x1e90 net/core/rtnetlink.c:4064
1 lock held by syz-executor/14619:
 #0: 
ffffffff8a631a48
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978
1 lock held by syz-executor/14623:
 #0: 
ffffffff8a631a48
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978
1 lock held by syz-executor/14627:
 #0: 
ffffffff8a631a48
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978

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

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 10/02/2025
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]
 check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
 watchdog+0xf3f/0x1170 kernel/hung_task.c:495
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x56d/0x700 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </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 10/02/2025
Workqueue: events dvb_usb_read_remote_control
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:401
Code: 8b a0 fe 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 1a 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c e9 cd 9b 69 04 e8 38 c4 00 ff eb a2 e8 c1 c4
RSP: 0018:ffffc900000af720 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff82ddc2e0 RDI: ffffffff93bdc700
RBP: ffffffff93bdc6c0 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000020 R14: fffffbfff277b932 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888268ea0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558907e30390 CR3: 0000000116da8000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 serial_in drivers/tty/serial/8250/8250.h:137 [inline]
 serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
 wait_for_lsr+0x13a/0x210 drivers/tty/serial/8250/8250_port.c:1961
 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline]
 serial8250_console_write+0xf81/0x1890 drivers/tty/serial/8250/8250_port.c:3342
 console_emit_next_record kernel/printk/printk.c:3111 [inline]
 console_flush_all+0x801/0xc60 kernel/printk/printk.c:3199
 __console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
 console_unlock+0xd8/0x210 kernel/printk/printk.c:3298
 vprintk_emit+0x3d7/0x680 kernel/printk/printk.c:2423
 _printk+0xc7/0x100 kernel/printk/printk.c:2448
 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+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x56d/0x700 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>