INFO: task kworker/1:9:8150 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:9 state:D stack:22472 pid:8150 ppid:2 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
usb_audio_probe+0x3b3/0x1df0 sound/usb/card.c:813
usb_probe_interface+0x5c9/0xb20 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x25b/0xb20 drivers/base/dd.c:658
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
__device_attach_driver+0x2ca/0x510 drivers/base/dd.c:958
bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
__device_attach+0x2c2/0x420 drivers/base/dd.c:1030
bus_probe_device+0x180/0x260 drivers/base/bus.c:534
device_add+0x85b/0xc20 drivers/base/core.c:3683
usb_set_configuration+0x1a79/0x20c0 drivers/usb/core/message.c:2265
usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:238
usb_probe_device+0x13d/0x270 drivers/usb/core/driver.c:293
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x25b/0xb20 drivers/base/dd.c:658
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
__device_attach_driver+0x2ca/0x510 drivers/base/dd.c:958
bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
__device_attach+0x2c2/0x420 drivers/base/dd.c:1030
bus_probe_device+0x180/0x260 drivers/base/bus.c:534
device_add+0x85b/0xc20 drivers/base/core.c:3683
usb_new_device+0xa3c/0x1660 drivers/usb/core/hub.c:2660
hub_port_connect drivers/usb/core/hub.c:5529 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5669 [inline]
port_event drivers/usb/core/hub.c:5833 [inline]
hub_event+0x29bf/0x49f0 drivers/usb/core/hub.c:5915
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Showing all locks held in the system:
6 locks held by kworker/0:0/8:
#0: ffff888019af8138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888019af8138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc900000d7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc900000d7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#2: ffff88802562f190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#2: ffff88802562f190 (&dev->mutex){....}-{3:3}, at: hub_event+0x180/0x49f0 drivers/usb/core/hub.c:5861
#3: ffff88802711e190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#3: ffff88802711e190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x420 drivers/base/dd.c:1005
#4: ffff88802d95c160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#4: ffff88802d95c160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x420 drivers/base/dd.c:1005
#5: ffffffff8e364c68 (register_mutex#6){+.+.}-{3:3}, at: usb_audio_probe+0x3b3/0x1df0 sound/usb/card.c:813
2 locks held by kworker/1:1/27:
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc90000a2fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90000a2fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
1 lock held by khungtaskd/29:
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
6 locks held by kworker/0:2/967:
#0: ffff888019af8138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888019af8138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc9000440fd00
((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#2:
ffff888143790190
(&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
(&dev->mutex){....}-{3:3}, at: hub_event+0x180/0x49f0 drivers/usb/core/hub.c:5861
#3: ffff88805d5f0190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#3: ffff88805d5f0190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x420 drivers/base/dd.c:1005
#4: ffff88802ea26160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#4: ffff88802ea26160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x420 drivers/base/dd.c:1005
#5: ffffffff8e364c68 (register_mutex#6
){+.+.}-{3:3}, at: usb_audio_probe+0x3b3/0x1df0 sound/usb/card.c:813
1 lock held by dhcpcd/5434:
#0: ffffffff8e3c2ac8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x30c/0x1c40 net/ipv4/devinet.c:1101
2 locks held by getty/5527:
#0: ffff88814c80e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1:
ffffc9000326e2f0
(
&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
4 locks held by udevd/5766:
#0: ffff888075c9a8b8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb1/0xd50 fs/seq_file.c:182
#1: ffff888062c55088 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x5c/0x410 fs/kernfs/file.c:172
#2: ffff888063d199b8 (kn->active#22){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888063d199b8 (kn->active#22){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x410 fs/kernfs/file.c:173
#3: ffff88802711e190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:1000 [inline]
#3: ffff88802711e190 (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
2 locks held by kworker/1:3/5813:
#0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc900048b7d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc900048b7d00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
9 locks held by kworker/0:5/5816:
6 locks held by kworker/1:9/8150:
#0: ffff888019af8138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888019af8138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1:
ffffc90003477d00
((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#2: ffff8880257af190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#2: ffff8880257af190 (&dev->mutex){....}-{3:3}, at: hub_event+0x180/0x49f0 drivers/usb/core/hub.c:5861
#3: ffff888022341190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#3: ffff888022341190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x420 drivers/base/dd.c:1005
#4: ffff88807cebe160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#4: ffff88807cebe160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x420 drivers/base/dd.c:1005
#5: ffffffff8e364c68 (register_mutex#6){+.+.}-{3:3}, at: usb_audio_probe+0x3b3/0x1df0 sound/usb/card.c:813
4 locks held by udevd/8956:
#0: ffff888067a5f668 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb1/0xd50 fs/seq_file.c:182
#1: ffff88801bf98c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x5c/0x410 fs/kernfs/file.c:172
#2: ffff88806b3a0100 (kn->active#22){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88806b3a0100 (kn->active#22){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x410 fs/kernfs/file.c:173
#3:
ffff88805d5f0190
(
&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:1000 [inline]
&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
4 locks held by udevd/8958:
#0: ffff88806d888b08 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb1/0xd50 fs/seq_file.c:182
#1: ffff88806a870888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x5c/0x410 fs/kernfs/file.c:172
#2: ffff88805d1d62f0 (kn->active#22){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88805d1d62f0 (kn->active#22){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x410 fs/kernfs/file.c:173
#3: ffff88806390a190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:1000 [inline]
#3: ffff88806390a190 (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
4 locks held by udevd/8970:
#0: ffff88802ec72418 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb1/0xd50 fs/seq_file.c:182
#1: ffff888063f56088 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x5c/0x410 fs/kernfs/file.c:172
#2: ffff88806c8ce8c0 (kn->active#22){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88806c8ce8c0 (kn->active#22){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x410 fs/kernfs/file.c:173
#3: ffff888022341190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:1000 [inline]
#3: ffff888022341190 (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
2 locks held by syz.1.1613/13301:
#0: ffffffff8e3c2ac8
(rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
(rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511
#1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
1 lock held by syz.4.1617/13314:
#0: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#0: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf3d/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 13314 Comm: syz.4.1617 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:126 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:133 [inline]
RIP: 0010:debug_check_no_locks_freed+0x206/0x3e0 kernel/locking/lockdep.c:6593
Code: 10 84 c0 0f 85 ad 01 00 00 83 3d 14 73 22 0d 00 74 75 48 8b 5c 24 38 c6 44 13 04 00 48 c7 44 24 60 00 00 00 00 9c 8f 44 24 60 44 24 60 00 02 00 00 c6 44 13 04 f8 0f 85 fb 00 00 00 f7 44 24
RSP: 0018:ffffc90003417760 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 1ffff92000682ef4 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000001000 RDI: ffff88806c1c7000
RBP: ffffc90003417848 R08: ffffffff8e8b19af R09: 1ffffffff1d16335
R10: dffffc0000000000 R11: fffffbfff1d16336 R12: ffff88806c1c7000
R13: 1ffff1100572e15b R14: ffff88802b970000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff031ba97d0 CR3: 00000000312b5000 CR4: 00000000003506f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000007
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
free_pages_prepare mm/page_alloc.c:1185 [inline]
free_unref_page_prepare+0x1cf/0x8c0 mm/page_alloc.c:2365
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458
vfree+0x1a6/0x320 mm/vmalloc.c:2868
kcov_put kernel/kcov.c:438 [inline]
kcov_close+0x2b/0x50 kernel/kcov.c:534
__fput+0x234/0x970 fs/file_table.c:384
task_work_run+0x1d4/0x260 kernel/task_work.c:245
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x95a/0x2460 kernel/exit.c:883
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
get_signal+0x12fc/0x13f0 kernel/signal.c:2902
arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f072679ca6b
Code: Unable to access opcode bytes at 0x7f072679ca41.
RSP: 002b:00007f0727669f00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007f072679ca6b
RDX: 00007f072766afd0 RSI: 0000000080085502 RDI: 0000000000000003
RBP: 00007f072766afd0 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502
R13: 0000000800000000 R14: 0000000000000000 R15: 00007f07268511da