syzbot

INFO: task kworker/u8:7:1602 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:7    state:D
 stack:23736 pid:1602  tgid:1602  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events_unbound fsnotify_mark_destroy_workfn

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x1325/0x3b10 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6879
 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x2ff/0x4e0 kernel/sched/completion.c:116
 __synchronize_srcu+0x1b3/0x290 kernel/rcu/srcutree.c:1442
 fsnotify_mark_destroy_workfn+0x112/0x350 fs/notify/mark.c:996
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/0:0/9:
4 locks held by kworker/0:1/10:
5 locks held by ksoftirqd/0/14:
1 lock held by khungtaskd/30:
 #0: 
ffffffff890c8440
 (
rcu_read_lock
){....}-{1:3}
, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
7 locks held by kworker/0:2/349:
7 locks held by kworker/1:2/912:
 #0: 
ffff8881072ab148
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: 
ffffc9000189fd10
 (
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: 
ffff88810af77198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:884 [inline]
, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898
 #3: 
ffff88811c5a6198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:884 [inline]
, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #4: 
ffff888119533160
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:884 [inline]
, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #5: 
ffff888119534088
 (
&ictx->lock
){+.+.}-{4:4}
, at: imon_init_intf0 drivers/media/rc/imon.c:2233 [inline]
, at: imon_probe+0x9e2/0x3ac0 drivers/media/rc/imon.c:2434
 #6: 
ffffffff89e0dd28
 (
input_mutex
){+.+.}-{4:4}
, at: class_mutex_intr_constructor include/linux/mutex.h:227 [inline]
, at: input_register_device+0x98a/0x1130 drivers/input/input.c:2408
2 locks held by kworker/u8:7/1602:
2 locks held by kworker/u8:8/1608:
2 locks held by getty/2905:
 #0: 
ffff88811235e0a0
 (
&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
4 locks held by udevd/5797:
 #0: 
ffff88813169d668
 (
&p->lock
){+.+.}-{4:4}
, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
 #1: 
ffff88811b36dc88
 (
&of->mutex
#2
){+.+.}-{4:4}
, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
 #2: 
ffff8881149df008
 (
kn->active
#9
){.+.+}-{0:0}
, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
 #3: 
ffff888107b34198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock_interruptible include/linux/device.h:889 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
5 locks held by kworker/0:3/5814:
1 lock held by udevd/5823:
 #0: 
ffffffff890d3a38
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336
1 lock held by udevd/5839:
 #0: 
ffffffff890d3a38
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:304
4 locks held by udevd/5841:
 #0: 
ffff888124339668
 (
&p->lock
){+.+.}-{4:4}
, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
 #1: 
ffff8881086db888
 (
&of->mutex
#2
){+.+.}-{4:4}
, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
 #2: 
ffff88811472f008
 (
kn->active
#9
){.+.+}-{0:0}
, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
 #3: 
ffff888114437198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock_interruptible include/linux/device.h:889 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
4 locks held by udevd/5842:
 #0: 
ffff88812767f790
 (
&p->lock
){+.+.}-{4:4}
, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
 #1: 
ffff88811b199888
 (
&of->mutex
#2
){+.+.}-{4:4}
, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
 #2: 
ffff8881135ecd28
 (
kn->active
#9
){.+.+}-{0:0}
, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
 #3: 
ffff88811c5a6198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock_interruptible include/linux/device.h:889 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xf70/0x12c0 kernel/hung_task.c:470
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
imon 8-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14 Comm: ksoftirqd/0 Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:416
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 e9 46 87 5c 04 e8 c1 1e 05 ff eb a0 e8 4a 1f 05
RSP: 0018:ffffc900000ef340 EFLAGS: 00000002
RAX: 0000000000000033 RBX: 00000000000003f8 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: ffffffff82d57865 RDI: ffffffff9392af80
RBP: ffffffff9392af40 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000033 R14: ffffffff9392af40 R15: ffffffff82d57800
FS:  0000000000000000(0000) GS:ffff888269160000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f895b690254 CR3: 0000000111dda000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 serial_port_out include/linux/serial_core.h:798 [inline]
 serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3306 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
 serial8250_console_write+0xfbc/0x1890 drivers/tty/serial/8250/8250_port.c:3456
 console_emit_next_record kernel/printk/printk.c:3138 [inline]
 console_flush_all+0x801/0xc60 kernel/printk/printk.c:3226
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xd8/0x210 kernel/printk/printk.c:3325
 vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450
 dev_vprintk_emit drivers/base/core.c:4917 [inline]
 dev_printk_emit+0xfa/0x140 drivers/base/core.c:4928
 __dev_printk+0xf5/0x270 drivers/base/core.c:4940
 _dev_warn+0xe4/0x120 drivers/base/core.c:4984
 usb_rx_callback_intf0+0x11c/0x1a0 drivers/media/rc/imon.c:1768
 __usb_hcd_giveback_urb+0x38d/0x6e0 drivers/usb/core/hcd.c:1663
 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1747
 dummy_timer+0x1814/0x3a30 drivers/usb/gadget/udc/dummy_hcd.c:1995
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825
 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1842
 handle_softirqs+0x208/0x8d0 kernel/softirq.c:579
 run_ksoftirqd kernel/softirq.c:968 [inline]
 run_ksoftirqd+0x3a/0x60 kernel/softirq.c:960
 smpboot_thread_fn+0x3f4/0xae0 kernel/smpboot.c:164
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>