INFO: task kworker/1:2:1215 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:2 state:D stack:20888 pid:1215 tgid:1215 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
hub_port_connect drivers/usb/core/hub.c:5473 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
port_event drivers/usb/core/hub.c:5879 [inline]
hub_event+0x20c9/0x4d30 drivers/usb/core/hub.c:5961
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
5 locks held by kworker/0:1/10:
#0: ffff8880236b6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff8880236b6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc900000f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc900000f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffff88802b2d01d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802b2d01d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5907
#3: ffff88802b2d5568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3260 [inline]
#3: ffff88802b2d5568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5472 [inline]
#3: ffff88802b2d5568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
#3: ffff88802b2d5568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5879 [inline]
#3: ffff88802b2d5568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30 drivers/usb/core/hub.c:5961
#4: ffff88802b1b8e60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5473 [inline]
#4: ffff88802b1b8e60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
#4: ffff88802b1b8e60 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5879 [inline]
#4: ffff88802b1b8e60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30 drivers/usb/core/hub.c:5961
1 lock held by khungtaskd/30:
#0:
ffffffff8eb59c60
(
rcu_read_lock){....}-{1:3}
, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/1:2/1215:
#0: ffff8880236b6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff8880236b6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc900057d7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc900057d7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffff88802b22e1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802b22e1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5907
#3: ffff88802b2c3568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3260 [inline]
#3: ffff88802b2c3568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5472 [inline]
#3: ffff88802b2c3568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
#3: ffff88802b2c3568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5879 [inline]
#3: ffff88802b2c3568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30 drivers/usb/core/hub.c:5961
#4: ffff88802b238460 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5473 [inline]
#4: ffff88802b238460 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
#4: ffff88802b238460 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5879 [inline]
#4: ffff88802b238460 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30 drivers/usb/core/hub.c:5961
2 locks held by getty/5366:
#0: ffff888036a780a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5625:
#0:
ffffffff8eb5ff68
(rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
(rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
5 locks held by kworker/0:3/5671:
#0: ffff8880236b6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff8880236b6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9000409fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9000409fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffff88802b20e1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802b20e1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5907
#3: ffff88802b221568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3260 [inline]
#3: ffff88802b221568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5472 [inline]
#3: ffff88802b221568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
#3: ffff88802b221568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5879 [inline]
#3: ffff88802b221568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30 drivers/usb/core/hub.c:5961
#4: ffff88802b238460 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5473 [inline]
#4: ffff88802b238460 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
#4: ffff88802b238460 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5879 [inline]
#4: ffff88802b238460 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30 drivers/usb/core/hub.c:5961
7 locks held by kworker/1:9/5705:
#0: ffff8880b863b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb2/0x160 kernel/sched/core.c:675
#1: ffff8880b8724440 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x57/0x7d0 kernel/sched/psi.c:933
#2: ffff8880b8726058 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1004 [inline]
#2: ffff8880b8726058 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1a9/0xed0 kernel/time/timer.c:1085
#3: ffffffff9aa71b08 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0xb7/0x420 lib/debugobjects.c:873
#4: ffffffff8eb4bf40 (console_owner){-.-.}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:305 [inline]
#4: ffffffff8eb4bf40 (console_owner){-.-.}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:428 [inline]
#4: ffffffff8eb4bf40 (console_owner){-.-.}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:291 [inline]
#4: ffffffff8eb4bf40 (console_owner){-.-.}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3246 [inline]
#4: ffffffff8eb4bf40 (console_owner){-.-.}-{0:0}, at: console_flush_all+0x123/0xaf0 kernel/printk/printk.c:3343
#5: ffffffff8eb4bef8 (console_owner_lock){-.-.}-{2:2}, at: console_lock_spinning_disable_and_check+0x35/0x100 kernel/printk/printk.c:1941
#6: ffffffff9aae2478 (&port_lock_key){-.-.}-{3:3}, at: uart_port_lock_irqsave include/linux/serial_core.h:719 [inline]
#6: ffffffff9aae2478 (&port_lock_key){-.-.}-{3:3}, at: serial8250_console_write+0x153/0x1ba0 drivers/tty/serial/8250/8250_port.c:3344
1 lock held by syz.1.4342/19654:
#0:
ffff888074cfd460
(&pipe->mutex){+.+.}-{4:4}, at: pipe_release+0x48/0x330 fs/pipe.c:827
1 lock held by syz.1.4342/19658:
#0: ffff888074cfd460 (&pipe->mutex){+.+.}-{4:4}, at: splice_file_to_pipe+0x3e/0x6b0 fs/splice.c:1287
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 43 Comm: kworker/1:1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:sched_core_idle_cpu+0x4c/0x1f0 kernel/sched/syscalls.c:200
Code: 00 00 fc ff df 4c 8d 24 dd d0 b7 4f 8e 4d 89 e6 49 c1 ee 03 43 80 3c 2e 00 74 08 4c 89 e7 e8 db f8 96 00 49 c7 c7 00 21 6f 93 <4d> 03 3c 24 e9 08 01 00 00 83 fd 08 0f 83 b2 00 00 00 43 80 3c 2e
RSP: 0000:ffffc90000a08f90 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000001
RDX: 0000000000010000 RSI: ffffffff8c4bbe60 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffffffff90578f37 R09: 1ffffffff20af1e6
R10: dffffc0000000000 R11: fffffbfff20af1e7 R12: ffffffff8e4fb7d8
R13: dffffc0000000000 R14: 1ffffffff1c9f6fb R15: ffffffff936f2100
FS: 0000000000000000(0000) GS:ffff888125049000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000033414ff8 CR3: 0000000074f3c000 CR4: 00000000003526f0
DR0: 0000000000000013 DR1: 0000000000000006 DR2: 0000000000000084
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
tick_irq_exit kernel/softirq.c:695 [inline]
__irq_exit_rcu+0xdb/0x220 kernel/softirq.c:742
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline]
RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478
Code: 0f 84 44 ff ff ff e8 62 67 21 00 fb eb 44 e8 5a 67 21 00 e8 45 cb 2c 0a 4d 85 f6 74 94 e8 4b 67 21 00 fb 48 c7 c7 a0 bf b4 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 fb 1b
RSP: 0000:ffffc90000b37840 EFLAGS: 00000293
RAX: ffffffff81a59a45 RBX: ffffffff81a598bf RCX: ffff888021addd00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8eb4bfa0
RBP: ffffc90000b378f0 R08: ffffffff90578f37 R09: 1ffffffff20af1e6
R10: dffffc0000000000 R11: fffffbfff20af1e7 R12: 0000000000000000
R13: 0000000000000017 R14: 0000000000000200 R15: 1ffff92000166f0c
_printk+0xdd/0x130 kernel/printk/printk.c:2504
m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline]
m920x_rc_query+0x2f1/0x830 drivers/media/usb/dvb-usb/m920x.c:-1
legacy_dvb_usb_read_remote_control+0x107/0x450 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245