INFO: task kworker/1:2:2500 blocked for more than 143 seconds.
Not tainted 6.16.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:2 state:D
stack:21528 pid:2500 tgid:2500 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: events kernfs_notify_workfn
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x132a/0x3b10 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6878
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
rwsem_down_read_slowpath+0x62f/0xb60 kernel/locking/rwsem.c:1084
__down_read_common kernel/locking/rwsem.c:1248 [inline]
__down_read kernel/locking/rwsem.c:1261 [inline]
down_read+0xef/0x480 kernel/locking/rwsem.c:1526
kernfs_notify_workfn+0xff/0xb30 fs/kernfs/file.c:915
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+0x3c5/0x780 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
INFO: task kworker/0:3:5231 blocked for more than 143 seconds.
Not tainted 6.16.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:3 state:D
stack:22064 pid:5231 tgid:5231 ppid:2 task_flags:0x4288060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x132a/0x3b10 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6878
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
rwsem_down_write_slowpath+0x524/0x1310 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1d6/0x200 kernel/locking/rwsem.c:1578
kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712
kernfs_remove_by_name include/linux/kernfs.h:633 [inline]
remove_files+0x96/0x1c0 fs/sysfs/group.c:28
sysfs_remove_group+0x8b/0x180 fs/sysfs/group.c:322
sysfs_remove_groups fs/sysfs/group.c:346 [inline]
sysfs_remove_groups+0x60/0xa0 fs/sysfs/group.c:338
device_remove_groups drivers/base/core.c:2846 [inline]
device_remove_attrs+0x192/0x290 drivers/base/core.c:2976
device_del+0x38e/0x9f0 drivers/base/core.c:3880
usb_disconnect+0x594/0x920 drivers/usb/core/hub.c:2344
hub_port_connect drivers/usb/core/hub.c:5375 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5675 [inline]
port_event drivers/usb/core/hub.c:5835 [inline]
hub_event+0x1aa0/0x5030 drivers/usb/core/hub.c:5917
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+0x3c5/0x780 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
Showing all locks held in the system:
2 locks held by kworker/0:0/9:
5 locks held by kworker/1:0/23:
#0: ffff8881072e9d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc9000018fd10
(
(work_completion)(&hub->events)
){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffff88810b3f0198
(
&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863
#3:
ffff88811ec3c198
(&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:884 [inline]
, at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2307
#4: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712
1 lock held by khungtaskd/30:
#0:
ffffffff890c7d80
(
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
3 locks held by kworker/u8:3/47:
#0: ffff888100ac3948
((wq_completion)netns){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1:
ffffc90000527d10
(net_cleanup_work
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffffffff8a3becd0
(pernet_ops_rwsem
){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:662
8 locks held by kworker/0:2/1115:
2 locks held by kworker/u8:6/1629:
#0:
ffff888100089148
(
(wq_completion)events_unbound){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc9000222fd10
((work_completion)(&sub_info->work)
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
4 locks held by kworker/1:2/2500:
#0:
ffff888100080d48 ((wq_completion)events){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc9000361fd10 (kernfs_notify_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffff888100ac4ab8
(&root->kernfs_supers_rwsem){++++}-{4:4}
, at: kernfs_notify_workfn+0xf7/0xb30 fs/kernfs/file.c:914
#3: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}
, at: kernfs_notify_workfn+0xff/0xb30 fs/kernfs/file.c:915
1 lock held by udevd/2843:
#0:
ffff888100ac4988
(
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
2 locks held by getty/2905:
#0:
ffff8881122c60a0
(
&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
1 lock held by syz-executor/2956:
#0:
ffff8881f5838858
(
&rq->__lock
){-.-.}-{2:2}
, at: raw_spin_rq_lock_nested kernel/sched/core.c:606 [inline]
, at: raw_spin_rq_lock kernel/sched/sched.h:1532 [inline]
, at: rq_lock kernel/sched/sched.h:1856 [inline]
, at: __schedule+0x2f0/0x3b10 kernel/sched/core.c:6709
1 lock held by syz-executor/2958:
#0:
ffffffff890d3378
(
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336
1 lock held by udevd/5217:
#0: ffff888100ac4988 (&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
5 locks held by kworker/0:3/5231:
#0: ffff8881072e9d48 ((wq_completion)usb_hub_wq
){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc900033afd10 ((work_completion)(&hub->events)){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2:
ffff88810b310198
(
&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863
#3:
ffff88810b313508 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline]
ffff88810b313508 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5432 [inline]
ffff88810b313508 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline]
ffff88810b313508 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5835 [inline]
ffff88810b313508 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x29da/0x5030 drivers/usb/core/hub.c:5917
#4: ffff888109f6ff68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5433 [inline]
#4: ffff888109f6ff68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline]
#4: ffff888109f6ff68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5835 [inline]
#4: ffff888109f6ff68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2a00/0x5030 drivers/usb/core/hub.c:5917
6 locks held by kworker/1:4/5246:
5 locks held by kworker/1:5/5256:
#0: ffff8881072e9d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc90003487d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffff88810b3d8198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#2: ffff88810b3d8198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863
#3: ffff88811dbd1198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#3: ffff88811dbd1198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2307
#4: ffff888100ac4988 (&root->kernfs_rwsem
){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712
1 lock held by udevd/5272:
#0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
4 locks held by udevd/5380:
#0: ffff888125298b08 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
#1: ffff888136b21c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#2: ffff8881339c3f08 (kn->active#18){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#3: ffff888101baf198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:889 [inline]
#3: ffff888101baf198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by udevd/5383:
#0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
2 locks held by kworker/0:5/5487:
#0: ffff888100080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1:
ffffc90012977d10 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
1 lock held by syz.0.537/7230:
#0:
ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712
1 lock held by syz.3.541/7240:
#0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712
1 lock held by syz-executor/7243:
#0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
1 lock held by syz-executor/7244:
#0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
1 lock held by syz-executor/7245:
#0: ffff888100ac4988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
1 lock held by syz-executor/7248:
#0: ffff888100ac4988 (
&root->kernfs_rwsem
){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
1 lock held by modprobe/7250:
#0: ffff888100ac4988 (&root->kernfs_rwsem
){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
__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+0x3c5/0x780 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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.16.0-rc2-syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:410
Code: 3d a8 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 e8 3a 05 ff eb a2 e8 71 3b
RSP: 0018:ffffc9000009f678 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff82d58ec0 RDI: ffffffff93927080
RBP: ffffffff93927040 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000020 R14: fffffbfff2724e62 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888269164000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c35a106 CR3: 000000011680e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:137 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
wait_for_lsr+0x137/0x210 drivers/tty/serial/8250/8250_port.c:2094
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline]
serial8250_console_write+0xf83/0x1890 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
_printk+0xc7/0x100 kernel/printk/printk.c:2475
m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline]
m920x_rc_query+0x496/0x770 drivers/media/usb/dvb-usb/m920x.c:193
legacy_dvb_usb_read_remote_control+0x109/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123
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+0x3c5/0x780 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