INFO: task kworker/1:2:1123 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:2     state:D
 stack:21176 pid:1123  tgid:1123  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5260 [inline]
 __schedule+0xeb0/0x3e50 kernel/sched/core.c:6867
 __schedule_loop kernel/sched/core.c:6949 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:6964
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline]
 kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline]
 kobject_uevent_env+0xba8/0x18b0 lib/kobject_uevent.c:608
 device_add+0x116e/0x1950 drivers/base/core.c:3670
 usb_new_device.cold+0x685/0x115c 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+0x314d/0x4af0 drivers/usb/core/hub.c:5953
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x6c3/0xa20 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:
2 locks held by kworker/0:0/9:
3 locks held by kworker/1:0/23:
 #0: 
ffff888100071948
 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
 #1: 
ffffc9000018fca8
 (
free_ipc_work
){+.+.}-{0:0}
, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
 #2: 
ffffffff894e6b78
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by khungtaskd/30:
 #0: 
ffffffff894da3a0
 (
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+0x3d/0x184 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:4/49:
5 locks held by kworker/1:2/1123:
 #0: 
ffff888105693948
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
 #1: 
ffffc90001cdfca8
 (
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
 #2: 
ffff88810a706198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
 #3: 
ffff888103ee4198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1006
 #4: 
ffffffff8abb6908
 (
uevent_sock_mutex
){+.+.}-{4:4}
, at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline]
, at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline]
, at: kobject_uevent_env+0xba8/0x18b0 lib/kobject_uevent.c:608
2 locks held by getty/2925:
 #0: 
ffff8881086b50a0
 (
&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+0x419/0x1500 drivers/tty/n_tty.c:2211
4 locks held by udevd/5217:
 #0: 
ffff8881346722f0
 (
&p->lock
){+.+.}-{4:4}
, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:182
 #1: 
ffff888132e4fc88
 (
&of->mutex
#2
){+.+.}-{4:4}
, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
 #2: 
ffff8881349ca0f8
 (
kn->active
#9
){.+.+}-{0:0}
, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
 #3: 
ffff88811b44a198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock_interruptible include/linux/device.h:900 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
3 locks held by kworker/1:3/5231:
5 locks held by kworker/1:4/5232:
 #0: 
ffff888105693948
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
 #1: 
ffffc9000235fca8
 (
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
 #2: ffff888109fe6198 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
 #3: 
ffff88811b42d198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1006
 #4: 
ffff888105edc278
 (
&(&priv->bus_notifier)->rwsem
){++++}-{4:4}
, at: blocking_notifier_call_chain kernel/notifier.c:379 [inline]
, at: blocking_notifier_call_chain+0x53/0xa0 kernel/notifier.c:368
4 locks held by udevd/5297:
 #0: 
ffff8881349e78b8
 (
&p->lock
){+.+.}-{4:4}
, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:182
 #1: 
ffff88811a44ac88
 (
&of->mutex
#2
){+.+.}-{4:4}
, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
 #2: 
ffff88811997d788
 (
kn->active
#9
){.+.+}-{0:0}
, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
 #3: 
ffff88811b42d198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock_interruptible include/linux/device.h:900 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
5 locks held by kworker/0:7/5868:
 #0: 
ffff888105693948
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
 #1: 
ffffc9001314fca8
 (
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
 #2: 
ffff88810a306198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
 #3: 
ffff88811b44a198
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1006
 #4: 
ffffffff8abb6908
 (
uevent_sock_mutex
){+.+.}-{4:4}
, at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline]
, at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline]
, at: kobject_uevent_env+0xba8/0x18b0 lib/kobject_uevent.c:608
1 lock held by syz.1.237/6085:
 #0: 
ffffffff894e6b78
 (
rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by syz.2.239/6087:
 #0: 
ffff888109f54dc0
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: __device_driver_lock drivers/base/dd.c:1104 [inline]
, at: __driver_attach+0x20c/0x5c0 drivers/base/dd.c:1224
 #1: 
ffffffff8abb6908
 (
uevent_sock_mutex
){+.+.}-{4:4}
, at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline]
, at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline]
, at: kobject_uevent_env+0xba8/0x18b0 lib/kobject_uevent.c:608
2 locks held by syz-executor/6089:
 #0: ffffffff8a8b4770 (
pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: 
ffffffff8a8ccda8
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096
2 locks held by syz-executor/6097:
 #0: 
ffffffff8a8b4770
 (
pernet_ops_rwsem
){++++}-{4:4}
, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: 
ffffffff8a8ccda8 (
rtnl_mutex){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096
2 locks held by syz-executor/6106:
 #0: 
ffffffff8a8b4770
 (
pernet_ops_rwsem
){++++}-{4:4}
, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: 
ffffffff8a8ccda8
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096
2 locks held by syz-executor/6109:
 #0: 
ffffffff8a8b4770
 (
pernet_ops_rwsem
){++++}-{4:4}
, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: 
ffffffff8a8ccda8
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096
2 locks held by syz-executor/6116:
 #0: 
ffffffff8a8b4770
 (
pernet_ops_rwsem
){++++}-{4:4}
, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: 
ffffffff8a8ccda8
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096
2 locks held by syz-executor/6139:
 #0: 
ffffffff8a8b4770 (
pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: 
ffffffff8a8ccda8
 (
rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096
2 locks held by syz-executor/6147:
 #0: 
ffffffff8a8b4770
 (
pernet_ops_rwsem
){++++}-{4:4}
, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: 
ffffffff8a8ccda8
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096
2 locks held by syz-executor/6155:
 #0: 
ffffffff8a8b4770
 (
pernet_ops_rwsem
){++++}-{4:4}, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: ffffffff8a8ccda8
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096
2 locks held by syz-executor/6163:
 #0: 
ffffffff8a8b4770
 (
pernet_ops_rwsem
){++++}-{4:4}
, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: 
ffffffff8a8ccda8
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096
2 locks held by syz-executor/6171:
 #0: ffffffff8a8b4770
 (pernet_ops_rwsem
){++++}-{4:4}, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: 
ffffffff8a8ccda8
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2096
1 lock held by syz-executor/6189:
2 locks held by syz-executor/6197:
2 locks held by syz-executor/6206:
 #0: 
ffffffff8a8b4770
 (
pernet_ops_rwsem
){++++}-{4:4}
, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: 
ffffffff8abb6908 (uevent_sock_mutex){+.+.}-{4:4}
, at: uevent_net_init+0x210/0x330 lib/kobject_uevent.c:794
2 locks held by syz-executor/6213:
 #0: 
ffffffff8a8b4770 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: 
ffffffff8abb6908
 (
uevent_sock_mutex
){+.+.}-{4:4}
, at: uevent_net_init+0x210/0x330 lib/kobject_uevent.c:794
2 locks held by syz-executor/6221:
 #0: 
ffffffff8a8b4770
 (
pernet_ops_rwsem
){++++}-{4:4}
, at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:577
 #1: 
ffffffff8abb6908
 (
uevent_sock_mutex
){+.+.}-{4:4}
, at: uevent_net_init+0x210/0x330 lib/kobject_uevent.c:794

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

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+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:161 [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:346 [inline]
 watchdog+0xcc3/0xfe0 kernel/hung_task.c:515
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x6c3/0xa20 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:
yealink 3-1:36.0: unexpected response 0
yealink 3-1:36.0: urb_ctl_callback - urb status -71
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_power_efficient gc_worker
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 d1 6a 01 ff eb a0 e8 5a 6b 01
RSP: 0018:ffffc90000007470 EFLAGS: 00000002
RAX: 000000000000002e RBX: 00000000000003f8 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: ffffffff8311c005 RDI: ffffffff93f14fc0
RBP: ffffffff93f14f80 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 000000000000002e R14: 0000000000000010 R15: ffffffff8311bfa0
FS:  0000000000000000(0000) GS:ffff88826896a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000092a8000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 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+0xde8/0x1900 drivers/tty/serial/8250/8250_port.c:3342
 console_emit_next_record kernel/printk/printk.c:3129 [inline]
 console_flush_one_record+0x790/0xe50 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+0x103/0x260 kernel/printk/printk.c:3359
 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426
 dev_vprintk_emit+0x394/0x3e0 drivers/base/core.c:4914
 dev_printk_emit+0xd2/0x10d drivers/base/core.c:4925
 __dev_printk+0xcb/0x100 drivers/base/core.c:4937
 _dev_err+0xef/0x127 drivers/base/core.c:4980
 urb_ctl_callback.cold+0x41/0x8c drivers/input/misc/yealink.c:456
 __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+0xd85/0x3670 drivers/usb/gadget/udc/dummy_hcd.c:1995
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x516/0x990 kernel/time/hrtimer.c:1841
 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858
 handle_softirqs+0x1dd/0x8f0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xed/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:227 [inline]
RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:342 [inline]
RIP: 0010:gc_worker+0x2bb/0x1630 net/netfilter/nf_conntrack_core.c:1548
Code: 00 00 48 c7 c7 88 13 cd 8a e8 51 0c 27 fb 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 6f 12 4a fb 58 48 85 db 0f 85 93 0f 00 00 <e8> 80 17 4a fb 8b 1d fa ee 65 04 89 dd 31 ff 83 e5 01 89 ee e8 1c
RSP: 0018:ffffc9000009faf0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff86672f16
RDX: ffff888101ab0000 RSI: ffffffff86672f25 RDI: ffff888101ab0000
RBP: 000000000004d379 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000040000 R14: 00000000000269bd R15: 0000000000001770
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>