INFO: task kworker/1:0:23 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:21168 pid:23 tgid:23 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0xf89/0x4840 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7282 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339 __mutex_lock_common kernel/locking/mutex.c:712 [inline] __mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:806 class_mutex_constructor include/linux/mutex.h:253 [inline] usb_audio_probe+0x385/0x3b60 sound/usb/card.c:952 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:631 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:709 __driver_probe_device+0x22e/0x480 drivers/base/dd.c:871 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:901 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:1029 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1101 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1156 bus_probe_device+0x64/0x160 drivers/base/bus.c:613 device_add+0x1210/0x1950 drivers/base/core.c:3706 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:631 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:709 __driver_probe_device+0x22e/0x480 drivers/base/dd.c:871 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:901 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:1029 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1101 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1156 bus_probe_device+0x64/0x160 drivers/base/bus.c:613 device_add+0x1210/0x1950 drivers/base/core.c:3706 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+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 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: 6 locks held by kworker/1:0/23: #0: ffff888105affd40 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc9000018fd18 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffff88810cb621d8 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1040 [inline] , at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88813ac311d8 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1040 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #4: ffff8881262731a0 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1040 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #5: ffffffff8aa2ddc0 ( register_mutex#3){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] register_mutex#3){+.+.}-{4:4}, at: usb_audio_probe+0x385/0x3b60 sound/usb/card.c:952 6 locks held by kworker/1:1/28: #0: ffff888105affd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc900001e7d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffff88810c3c21d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88810c3c21d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff888120a1e1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #4: ffff88813b2301a0 ( &dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] &dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #5: ffffffff8aa2ddc0 (register_mutex#3){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #5: ffffffff8aa2ddc0 (register_mutex#3){+.+.}-{4:4}, at: usb_audio_probe+0x385/0x3b60 sound/usb/card.c:952 1 lock held by khungtaskd/30: #0: ffffffff896ddaa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff896ddaa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff896ddaa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/2926: #0: ffff8881086a50a0 (&tty->ldisc_sem){++++}-{0:0} , at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000452e8 ( &ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211 4 locks held by udevd/5204: #0: ffff888115df21b8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff88812186fc80 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888107b10788 (kn->active#9){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888107b10788 (kn->active#9){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff888120a1e1d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline] #3: ffff888120a1e1d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by udevd/5217: #0: ffff888115105758 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff888136a36c80 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888113e4ef08 (kn->active#9){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888113e4ef08 (kn->active#9){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff888136dd91d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline] ffff888136dd91d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by udevd/5233: #0: ffff88810cb10878 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff8881121c1080 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888113eae698 (kn->active#9){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888113eae698 (kn->active#9){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff88811d7fc1d8 ( &dev->mutex ){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline] ){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by udevd/5382: #0: ffff888113105758 ( &p->lock ){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff88810ab45080 (&of->mutex #2 ){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff88810fbc8e18 (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: ffff888112c2b1d8 ( &dev->mutex ){....}-{4:4} , at: device_lock_interruptible include/linux/device.h:1045 [inline] , at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 6 locks held by kworker/1:7/5395: 6 locks held by kworker/0:5/5412: #0: ffff888105affd40 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc90003fcfd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffff88810c78a1d8 (&dev->mutex ){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] ){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff888136dd91d8 ( &dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:1040 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #4: ffff88811f6021a0 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1040 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #5: ffffffff8aa2ddc0 ( register_mutex #3 ){+.+.}-{4:4} , at: class_mutex_constructor include/linux/mutex.h:253 [inline] , at: usb_audio_probe+0x385/0x3b60 sound/usb/card.c:952 6 locks held by kworker/0:6/5468: #0: ffff888105affd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0} , at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc90004037d18 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffff88810c7321d8 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:1040 [inline] , at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88811d7fc1d8 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1040 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #4: ffff888135d591a0 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:1040 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #5: ffffffff8aa2ddc0 ( register_mutex#3){+.+.}-{4:4} , at: class_mutex_constructor include/linux/mutex.h:253 [inline] , at: usb_audio_probe+0x385/0x3b60 sound/usb/card.c:952 4 locks held by udevd/5723: #0: ffff8881364b7638 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff888114cf7c80 ( &of->mutex #2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888135b7c968 (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: ffff88813ac311d8 (&dev->mutex ){....}-{4:4} , at: device_lock_interruptible include/linux/device.h:1045 [inline] , at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 1 lock held by syz.2.461/6572: #0: ffffffff896e95e8 ( rcu_state.exp_mutex ){+.+.}-{4:4} , at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 ============================================= 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: __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:162 [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:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 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: 5395 Comm: kworker/1:7 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:__lock_acquire+0x4cc/0x2630 kernel/locking/lockdep.c:5210 Code: ee ff ff 8b 4c 24 08 85 c0 0f 84 d8 fe ff ff 8b 05 c9 6b 78 12 85 c0 75 11 4d 63 ed 4c 0f a3 2d 9a bf 6f 0d 0f 83 aa 0b 00 00 <48> 8b 95 38 0b 00 00 85 c9 0f 84 97 01 00 00 c7 44 24 08 00 00 00 RSP: 0018:ffffc900001a8c50 EFLAGS: 00000047 RAX: 0000000000000000 RBX: ffff88811ebdaa20 RCX: 0000000000000007 RDX: 0000000000000000 RSI: ffff88811ebdaa20 RDI: ffff88811ebd9dc0 RBP: ffff88811ebd9dc0 R08: 0000000000000001 R09: 000000000000003f R10: 0000000000000007 R11: 0000000000000001 R12: 0000000000000000 R13: 000000000000003f R14: 0000000000000007 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff888268787000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055557dfea908 CR3: 0000000111b06000 CR4: 00000000003506f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:382 raw_spin_rq_lock_nested kernel/sched/core.c:652 [inline] raw_spin_rq_lock kernel/sched/sched.h:1624 [inline] rq_lock kernel/sched/sched.h:1968 [inline] ttwu_queue kernel/sched/core.c:3976 [inline] try_to_wake_up+0x669/0x1450 kernel/sched/core.c:4302 hrtimer_wakeup+0x47/0x60 kernel/time/hrtimer.c:2191 __run_hrtimer kernel/time/hrtimer.c:1930 [inline] __hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x8a/0xb0 arch/x86/kernel/apic/apic.c:1061 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 58 8d 20 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 26 88 20 00 48 85 ed 0f 85 27 01 00 00 38 8d 20 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00 RSP: 0018:ffffc90003d365f8 EFLAGS: 00000246 RAX: 0000000000100000 RBX: 000000000000001b RCX: ffffc90012c55000 RDX: 0000000000100000 RSI: ffffffff81923384 RDI: ffff88811ebd9dc0 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff920007a6cc1 R13: 0000000000000200 R14: ffff8881026f0000 R15: ffffc90003d367c0 dev_vprintk_emit+0x394/0x3e0 drivers/base/core.c:4930 dev_printk_emit+0xd2/0x10d drivers/base/core.c:4941 __dev_printk+0xcb/0x100 drivers/base/core.c:4953 _dev_err+0xef/0x127 drivers/base/core.c:4996 parse_uac2_sample_rate_range.cold+0xff/0x134 sound/usb/format.c:472 parse_audio_format_rates_v2v3+0x403/0xf70 sound/usb/format.c:709 parse_audio_format_i+0x8d0/0xc70 sound/usb/format.c:791 snd_usb_parse_audio_format+0x8d/0x280 sound/usb/format.c:869 snd_usb_get_audioformat_uac12 sound/usb/stream.c:864 [inline] __snd_usb_parse_audio_interface+0xa85/0x4710 sound/usb/stream.c:1209 snd_usb_parse_audio_interface+0x81/0x110 sound/usb/stream.c:1290 create_standard_audio_quirk+0x6b/0x120 sound/usb/quirks.c:104 snd_usb_create_quirk sound/usb/quirks.c:544 [inline] create_composite_quirk+0x257/0x510 sound/usb/quirks.c:52 snd_usb_create_quirk+0xad/0xf0 sound/usb/quirks.c:544 usb_audio_probe+0x969/0x3b60 sound/usb/card.c:1025 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:631 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:709 __driver_probe_device+0x22e/0x480 drivers/base/dd.c:871 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:901 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:1029 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1101 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1156 bus_probe_device+0x64/0x160 drivers/base/bus.c:613 device_add+0x1210/0x1950 drivers/base/core.c:3706 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:631 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:709 __driver_probe_device+0x22e/0x480 drivers/base/dd.c:871 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:901 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:1029 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1101 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1156 bus_probe_device+0x64/0x160 drivers/base/bus.c:613 device_add+0x1210/0x1950 drivers/base/core.c:3706 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+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245