INFO: task kworker/0:3:5213 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:3 state:D stack:21656 pid:5213 tgid:5213 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: 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 Showing all locks held in the system: 11 locks held by kworker/1:1/28: 1 lock held by khungtaskd/30: #0: ffffffff896de760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff896de760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff896de760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/2918: #0: ffff888115c3b0a0 (&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/5187: #0: ffff88810ebcbb08 (&p->lock){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff88811bddfc88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff8881146c34b8 ( kn->active #27 ){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] ){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff8881351711e0 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:954 [inline] #3: ffff8881351711e0 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by udevd/5207: #0: ffff88811495a2f0 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff888133144088 ( &of->mutex #2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff88811f37ef08 ( kn->active #27 ){++++}-{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: ffff8881103fe1e0 ( &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 6 locks held by kworker/0:3/5213: #0: ffff8881056c3d48 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc900031efd18 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff88810bbb81e0 ( &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: ffff88812311f1e0 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:949 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068 #4: ffff8881190161a8 ( &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/0:4/5220: #0: ffff8881056c3d48 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc9000321fd18 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff88810c3101e0 ( &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: ffff8881103fe1e0 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:949 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068 #4: ffff888122ecb1a8 ( &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/0:5/5225: #0: ffff8881056c3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0} , at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc9000324fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff88810bf001e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #2: ffff88810bf001e0 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff8881351711e0 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:949 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068 #4: ffff88811bdaa1a8 ( &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 4 locks held by udevd/5226: #0: ffff88813570c0a0 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff88811a6ef088 ( &of->mutex #2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff88811542b968 ( kn->active #27 ){++++}-{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: ffff88811de421e0 ( &dev->mutex ){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:954 [inline] ){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 6 locks held by kworker/1:6/5270: #0: ffff8881056c3d48 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc9000318fd18 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff88810bf901e0 ( &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: ffff88813a4951e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] ffff88813a4951e0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068 #4: ffff88813a70e1a8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #4: ffff88813a70e1a8 (&dev->mutex){....}-{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] #5: ffffffff8aa21188 (register_mutex#3){+.+.}-{4:4}, at: usb_audio_probe+0x38f/0x3a90 sound/usb/card.c:950 4 locks held by udevd/7707: #0: ffff88811c4938b8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff888133145088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888121e9e878 ( kn->active #27 ){++++}-{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: ffff88813a4951e0 ( &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 ============================================= 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: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 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 28 Comm: kworker/1:1 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:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:68 Code: 55 89 e8 30 f9 b7 ff e9 c7 f9 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 07 88 4e fd 05 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a8908 EFLAGS: 00000202 RAX: ffffffff819d3a1e RBX: 0000000000000002 RCX: ffffffff8b517108 RDX: ffffc900001a8a01 RSI: ffffc900001a8a68 RDI: ffffc900001a8a68 RBP: ffffc900001a8a18 R08: ffffffff8b51710c R09: 0000000000000007 R10: 0000000000000200 R11: 00000000000067be R12: ffffc900001a8a20 R13: ffffc900001a89d0 R14: ffffc900001a8a70 R15: ffffc900001a8a04 FS: 0000000000000000(0000) GS:ffff8882687c9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe53dd9fc0 CR3: 0000000117020000 CR4: 00000000003506f0 Call Trace: deref_stack_reg arch/x86/kernel/unwind_orc.c:422 [inline] unwind_next_frame+0xb1d/0x1ea0 arch/x86/kernel/unwind_orc.c:600 __unwind_start+0x3d1/0x7f0 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24 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] kmem_cache_free+0x105/0x640 mm/slub.c:6295 ptlock_free+0x45/0x60 mm/memory.c:7479 pagetable_dtor include/linux/mm.h:3529 [inline] pagetable_dtor_free include/linux/mm.h:3536 [inline] __tlb_remove_table include/asm-generic/tlb.h:221 [inline] __tlb_remove_table_free mm/mmu_gather.c:228 [inline] tlb_remove_table_rcu+0xa2/0x380 mm/mmu_gather.c:291 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 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 f8 5f 20 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00 RSP: 0018:ffffc900001e6638 EFLAGS: 00000246 RAX: 0000000000100000 RBX: 000000000000001b RCX: ffffc90010536000 RDX: 0000000000100000 RSI: ffffffff81919d64 RDI: ffff8881026b1d80 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff9200003ccc9 R13: 0000000000000200 R14: ffff8881026b0000 R15: ffffc900001e6800 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+0x403/0xf70 sound/usb/format.c:705 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