INFO: task syz.2.2435:14062 blocked for more than 143 seconds.
      Not tainted syzkaller #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2435      state:D
 stack:27048 pid:14062 tgid:14061 ppid:2977   task_flags:0x40044c flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1138/0x47e0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
 rwsem_down_write_slowpath+0x4c2/0x12c0 kernel/locking/rwsem.c:1215
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1626
 kernfs_remove_by_name_ns+0x51/0x120 fs/kernfs/dir.c:1793
 sysfs_remove_file include/linux/sysfs.h:780 [inline]
 driver_remove_file drivers/base/driver.c:201 [inline]
 driver_remove_file+0x4a/0x60 drivers/base/driver.c:197
 remove_bind_files drivers/base/bus.c:683 [inline]
 bus_remove_driver+0x248/0x2e0 drivers/base/bus.c:821
 driver_unregister+0x76/0xb0 drivers/base/driver.c:277
 usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1757
 raw_release+0x19b/0x260 drivers/usb/gadget/legacy/raw_gadget.c:463
 __fput+0x3ff/0xb50 fs/file_table.c:510
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x951/0x2af0 kernel/exit.c:976
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1119
 get_signal+0x20ff/0x2210 kernel/signal.c:3037
 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x83/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x682/0x7f0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd2d2d5caeb
RSP: 002b:00007fd2d17acf00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007fd2d2d5caeb
RDX: 00007fd2d17adfd0 RSI: 0000000080085502 RDI: 0000000000000003
RBP: 00007fd2d17adfd0 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502
R13: 0000000800000000 R14: 0000000000000003 R15: 00007fd2d2e1125f
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/0:0/9:
 #0: 
ffff8881056e3140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289
 #1: 
ffffc9000009fd18
 ((work_completion)(&hub->events)){+.+.}-{0:0}
, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290
 #2: ffff88810bb151d8 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:1040 [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:1792
 #4: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x51/0x120 fs/kernfs/dir.c:1793
1 lock held by khungtaskd/30:
 #0: 
ffffffff896de960
 (
rcu_read_lock
){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:11/1647:
 #0: 
ffff888100e98940
 (
(wq_completion)netns
){+.+.}-{0:0}
, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289
 #1: 
ffffc90004c8fd18 (net_cleanup_work){+.+.}-{0:0}
, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290
 #2: 
ffffffff8aadc468
 (
pernet_ops_rwsem
){++++}-{4:4}
, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
 #3: 
ffffffff896ea4a8
 (
rcu_state.exp_mutex
){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by udevd/2862:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1218
2 locks held by getty/2924:
 #0: 
ffff888115fd30a0
 (
&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+0x419/0x14f0 drivers/tty/n_tty.c:2211
5 locks held by kworker/0:3/5226:
1 lock held by udevd/5229:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1218
2 locks held by kworker/0:4/5231:
4 locks held by kworker/0:5/5238:
 #0: 
ffff8881056e3140
 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289
 #1: 
ffffc9000205fd18
 (
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290
 #2: 
ffff88810b3ad1d8
 (
&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
 #3: 
ffff888100e87980
 (
&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:826
5 locks held by kworker/1:3/5282:
3 locks held by kworker/1:4/5291:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289
 #1: ffffc900020cfd18
 (
free_ipc_work
){+.+.}-{0:0}
, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290
 #2: 
ffffffff896ea4a8
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by udevd/5306:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1218
1 lock held by udevd/6866:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1218
5 locks held by kworker/0:2/8372:
3 locks held by syz.2.2435/14062:
 #0: 
ffff88810afdce00 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
ffff88810afdce00 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
ffff88810afdce00 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1372
 #1: 
ffff888100e87aa0 (&root->kernfs_supers_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x49/0x120 fs/kernfs/dir.c:1792
 #2: 
ffff888100e87980
 (&root->kernfs_rwsem){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x51/0x120 fs/kernfs/dir.c:1793
3 locks held by syz.0.2436/14064:
 #0: 
ffff88810afe4e00
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:1040 [inline]
, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1372
 #1: 
ffff888100e87aa0
 (
&root->kernfs_supers_rwsem
){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x49/0x120 fs/kernfs/dir.c:1792
 #2: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x51/0x120 fs/kernfs/dir.c:1793
2 locks held by syz.3.2438/14068:
 #0: 
ffff888100e87aa0 (&root->kernfs_supers_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x49/0x120 fs/kernfs/dir.c:1792
 #1: 
ffff888100e87980
 (
&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x51/0x120 fs/kernfs/dir.c:1793
1 lock held by syz.4.2439/14072:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:826
1 lock held by syz-executor/14074:
 #0: ffff888100e87980 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1218
1 lock held by syz-executor/14075:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1218
1 lock held by syz-executor/14076:
 #0: 
ffff888100e87980 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1218
1 lock held by syz-executor/14077:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1218
1 lock held by syz-executor/14078:
 #0: 
ffff888100e87980
 (
&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1218

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

NMI backtrace for cpu 1
CPU: 1 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:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
 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 1 to CPUs 0:
gspca_pac7302 2-1:0.0: URB error -71, resubmitting
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9333 Comm: kworker/0:7 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:402
Code: ef 8f 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 c3 cc cc cc cc e8 a8 aa f5 fe eb a2 e8 31 ab
RSP: 0018:ffffc90000007678 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff8322f5d0 RDI: ffffffff941da800
RBP: ffffffff941da7c0 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000020 R14: fffffbfff283b552 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8882686a5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000094ac000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 serial_in drivers/tty/serial/8250/8250.h:128 [inline]
 serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
 wait_for_lsr+0x13a/0x210 drivers/tty/serial/8250/8250_port.c:1973
 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3210 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3275 [inline]
 serial8250_console_write+0xdb9/0x1900 drivers/tty/serial/8250/8250_port.c:3360
 console_emit_next_record kernel/printk/printk.c:3183 [inline]
 console_flush_one_record+0x790/0xe50 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
 _printk+0xcf/0x110 kernel/printk/printk.c:2504
 int_irq.cold+0x1a/0x7f drivers/media/usb/gspca/gspca.c:104
 __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:1930 [inline]
 __hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994
 hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2011
 handle_softirqs+0x1dd/0x9e0 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:1061 [inline]
 sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_flush_one_record+0xac3/0xe50 kernel/printk/printk.c:3270
Code: 00 e8 f1 39 29 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 3f fc 20 00 48 85 ed 0f 85 d7 01 00 00 e8 51 01 21 00 fb 4c 89 e8 <48> c1 e8 03 42 80 3c 38 00 0f 85 64 03 00 00 48 8b 0c 24 48 8b 6b
RSP: 0018:ffffc90004a7f828 EFLAGS: 00000293
RAX: ffffffff89c7dfb8 RBX: ffffffff89c7df60 RCX: ffffffff8191e441
RDX: ffff88811ab0bb80 RSI: ffffffff8191e44f RDI: ffff88811ab0bb80
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000017ed6
R13: ffffffff89c7dfb8 R14: ffffc90004a7f8a8 R15: dffffc0000000000
 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
 _printk+0xcf/0x110 kernel/printk/printk.c:2504
 legacy_dvb_usb_read_remote_control.cold+0x11/0x16 drivers/media/usb/dvb-usb/dvb-usb-remote.c:124
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
 process_scheduled_works kernel/workqueue.c:3397 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
 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>