INFO: task kworker/0:6:5530 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:6     state:D
 stack:21144 pid:5530  tgid:5530  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xeb1/0x4220 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 class_mutex_constructor include/linux/mutex.h:253 [inline]
 usb_audio_probe+0x38f/0x3a90 sound/usb/card.c:950
 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:643 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:721
 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
 bus_probe_device+0x64/0x160 drivers/base/bus.c:613
 device_add+0x11d9/0x1950 drivers/base/core.c:3691
 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:643 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:721
 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
 bus_probe_device+0x64/0x160 drivers/base/bus.c:613
 device_add+0x11d9/0x1950 drivers/base/core.c:3691
 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+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: 
ffffffff896de760
 (
rcu_read_lock
){....}-{1:3}
, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
6 locks held by kworker/0:2/1119:
 #0: 
ffff8881062a9148
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
 #1: ffffc900034bfd18 (
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
 #2: 
ffff88810bf631e0
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:949 [inline]
, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
 #3: 
ffff8881197c41e0
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:949 [inline]
, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
 #4: 
ffff88813467b1a8
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:949 [inline]
, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
 #5: 
ffffffff8aa21188 (
register_mutex
#3
){+.+.}-{4:4}
, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
, at: usb_audio_probe+0x38f/0x3a90 sound/usb/card.c:950
6 locks held by kworker/1:2/2637:
 #0: ffff8881062a9148
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
 #1: 
ffffc900068efd18 ((work_completion)(&hub->events)){+.+.}-{0:0}
, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
 #2: 
ffff88810bfc31e0
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:949 [inline]
, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
 #3: 
ffff88811959f1e0
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:949 [inline]
, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
 #4: 
ffff88811959e1a8
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:949 [inline]
, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
 #5: 
ffffffff8aa21188
 (
register_mutex
#3
){+.+.}-{4:4}
, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
, at: usb_audio_probe+0x38f/0x3a90 sound/usb/card.c:950
2 locks held by getty/2917:
 #0: 
ffff888108ab90a0
 (
&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+0x419/0x1500 drivers/tty/n_tty.c:2211
4 locks held by udevd/5206:
 #0: 
ffff888120904d58
 (
&p->lock
){+.+.}-{4:4}
, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
 #1: 
ffff888107b90c88
 (
&of->mutex
#2
){+.+.}-{4:4}
, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
 #2: 
ffff88813a6f7d28
 (
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: 
ffff88813be601e0
 (
&dev->mutex
){....}-{4:4}
, at: device_lock_interruptible include/linux/device.h:954 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
4 locks held by udevd/5208:
 #0: 
ffff88811cfaa9e0
 (
&p->lock
){+.+.}-{4:4}
, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
 #1: 
ffff888115677c88
 (
&of->mutex
#2
){+.+.}-{4:4}
, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
 #2: 
ffff8881145b23c8
 (
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: 
ffff888114fd01e0
 (
&dev->mutex
){....}-{4:4}
, at: device_lock_interruptible include/linux/device.h:954 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
11 locks held by kworker/1:4/5224:
4 locks held by udevd/5232:
 #0: 
ffff88813cda09e0
 (
&p->lock
){+.+.}-{4:4}
, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
 #1: 
ffff88811035e088
 (
&of->mutex
#2
){+.+.}-{4:4}
, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
 #2: 
ffff88810ef7d0f8
 (
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: 
ffff8881197c41e0
 (
&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:954 [inline]
&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
6 locks held by kworker/1:6/5321:
 #0: ffff8881062a9148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
 #1: ffffc9000462fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
 #2: ffff88810bf8b1e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
 #2: ffff88810bf8b1e0 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
 #3: ffff888114fd01e0
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:949 [inline]
, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
 #4: 
ffff8881214571a8
 (
&dev->mutex
){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
 #5: 
ffffffff8aa21188
 (register_mutex#3){+.+.}-{4:4}
, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
, at: usb_audio_probe+0x38f/0x3a90 sound/usb/card.c:950
6 locks held by kworker/0:6/5530:
 #0: 
ffff8881062a9148
 (
(wq_completion)usb_hub_wq
){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
 #1: 
ffffc90012217d18
 (
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
 #2: ffff88810bfb31e0 (&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:949 [inline]
, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
 #3: 
ffff88810efb41e0 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:949 [inline]
, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
 #4: 
ffff888134a481a8
 (
&dev->mutex
){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
 #5: 
ffffffff8aa21188
 (
register_mutex
#3
){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
){+.+.}-{4:4}, at: usb_audio_probe+0x38f/0x3a90 sound/usb/card.c:950
4 locks held by udevd/5775:
 #0: 
ffff888122f078b8
 (
&p->lock
){+.+.}-{4:4}
, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
 #1: 
ffff888115e57c88
 (
&of->mutex
#2
){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
 #2: 
ffff8881052b61e8
 (
kn->active
#9){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#9){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
 #3: 
ffff88810efb41e0
 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:954 [inline]
 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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: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+0xd25/0x1050 kernel/hung_task.c:515
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5224 Comm: kworker/1:4 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:kasan_check_byte include/linux/kasan.h:402 [inline]
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5842 [inline]
RIP: 0010:lock_acquire+0x140/0x380 kernel/locking/lockdep.c:5825
Code: bd 07 00 4c 8b 14 24 65 49 ff 42 08 65 8b 05 4b 97 66 0b 83 f8 07 0f 86 10 ff ff ff 90 0f 0b 90 e9 07 ff ff ff 48 8b 74 24 68 <48> 89 ef e8 68 01 87 00 8b 0d 76 56 61 09 85 c9 0f 84 bd 00 00 00
RSP: 0018:ffffc900001a88f8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff816f8521 RDI: ffffffff891aabe8
RBP: ffffffff896de760 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 00000000000115ff R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8882687c9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555559ea9908 CR3: 0000000122b18000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x43/0x70 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1dc/0x640 mm/slub.c:6483
 free_slab_obj_exts mm/slub.c:2251 [inline]
 unaccount_slab mm/slub.c:3449 [inline]
 __free_slab+0x13d/0x220 mm/slub.c:3553
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2869
 handle_softirqs+0x1de/0x9d0 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:console_trylock_spinning kernel/printk/printk.c:2039 [inline]
RIP: 0010:vprintk_emit+0x553/0x6b0 kernel/printk/printk.c:2478
Code: 00 4d 85 ed 0f 85 1b 01 00 00 e8 18 60 20 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 e6 5a 20 00 48 85 ed 0f 85 27 01 00 00 <e8> f8 5f 20 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00
RSP: 0018:ffffc90003b4e638 EFLAGS: 00000246
RAX: 0000000000100000 RBX: 000000000000001b RCX: ffffc900116c2000
RDX: 0000000000100000 RSI: ffffffff81919d64 RDI: ffff8881195e3b00
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff92000769cc9
R13: 0000000000000200 R14: ffff888103eb5880 R15: ffffc90003b4e800
 dev_vprintk_emit+0x394/0x3e0 drivers/base/core.c:4915
 dev_printk_emit+0xd2/0x10d drivers/base/core.c:4926
 __dev_printk+0xcb/0x100 drivers/base/core.c:4938
 _dev_err+0xef/0x127 drivers/base/core.c:4981
 parse_uac2_sample_rate_range.cold+0x100/0x135 sound/usb/format.c:468
 parse_audio_format_rates_v2v3+0x2fe/0xf70 sound/usb/format.c:689
 parse_audio_format_i+0x8d0/0xc70 sound/usb/format.c:787
 snd_usb_parse_audio_format+0x8d/0x280 sound/usb/format.c:865
 snd_usb_get_audioformat_uac12 sound/usb/stream.c:856 [inline]
 __snd_usb_parse_audio_interface+0xa85/0x4710 sound/usb/stream.c:1201
 snd_usb_parse_audio_interface+0x81/0x110 sound/usb/stream.c:1282
 create_standard_audio_quirk+0x6b/0x120 sound/usb/quirks.c:101
 snd_usb_create_quirk sound/usb/quirks.c:541 [inline]
 create_composite_quirk+0x257/0x510 sound/usb/quirks.c:49
 snd_usb_create_quirk+0xad/0xf0 sound/usb/quirks.c:541
 usb_audio_probe+0x992/0x3a90 sound/usb/card.c:1023
 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:643 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:721
 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
 bus_probe_device+0x64/0x160 drivers/base/bus.c:613
 device_add+0x11d9/0x1950 drivers/base/core.c:3691
 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:643 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:721
 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
 bus_probe_device+0x64/0x160 drivers/base/bus.c:613
 device_add+0x11d9/0x1950 drivers/base/core.c:3691
 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+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>