INFO: task kworker/u8:1:32 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:1 state:D stack:26184 pid:32 tgid:32 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound fsnotify_connector_destroy_workfn Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145d/0x4a00 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121 __synchronize_srcu+0x14d/0x250 kernel/rcu/srcutree.c:1518 fsnotify_connector_destroy_workfn+0x4d/0xa0 fs/notify/mark.c:322 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 INFO: task kworker/u8:14:2675 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:14 state:D stack:23256 pid:2675 tgid:2675 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound fsnotify_mark_destroy_workfn Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145d/0x4a00 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121 __synchronize_srcu+0x14d/0x250 kernel/rcu/srcutree.c:1518 fsnotify_mark_destroy_workfn+0x112/0x350 fs/notify/mark.c:996 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 INFO: task kworker/1:5:5541 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:5 state:D stack:23208 pid:5541 tgid:5541 ppid:2 task_flags:0x4288060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145d/0x4a00 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121 __flush_work+0x7d7/0xcc0 kernel/workqueue.c:4277 __cancel_work_sync kernel/workqueue.c:4397 [inline] cancel_delayed_work_sync+0xd1/0xf0 kernel/workqueue.c:4471 quiesce_and_remove_host drivers/usb/storage/usb.c:939 [inline] usb_stor_disconnect+0xc5/0x270 drivers/usb/storage/usb.c:1186 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:571 [inline] device_remove+0x125/0x170 drivers/base/dd.c:563 __device_release_driver drivers/base/dd.c:1282 [inline] device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1305 bus_remove_device+0x22f/0x450 drivers/base/bus.c:616 device_del+0x396/0x9f0 drivers/base/core.c:3878 usb_disable_device+0x355/0x820 drivers/usb/core/message.c:1418 usb_disconnect+0x2e1/0x9e0 drivers/usb/core/hub.c:2345 hub_port_connect drivers/usb/core/hub.c:5407 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x1b50/0x5420 drivers/usb/core/hub.c:5953 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Showing all locks held in the system: 5 locks held by kworker/0:1/10: 6 locks held by kworker/1:0/23: #0: ffff8881056ec148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000018fca0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff88810a774198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810a774198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899 #3: ffff88810c6dd198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff88810c6dd198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9e0 drivers/usb/core/hub.c:2336 #4: ffff888104ac0160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff888104ac0160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline] #4: ffff888104ac0160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1302 #5: ffff88811a595a20 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #5: ffff88811a595a20 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline] #5: ffff88811a595a20 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1302 1 lock held by khungtaskd/30: #0: ffffffff892cd6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff892cd6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff892cd6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:1/32: #0: ffff888100089948 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc90000227ca0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 2 locks held by kworker/u8:14/2675: #0: ffff888100089948 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc90003affca0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 2 locks held by getty/2922: #0: ffff8881127fe0a0 (&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+0x41b/0x1510 drivers/tty/n_tty.c:2211 4 locks held by udevd/5219: #0: ffff888134cc88b8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12d0 fs/seq_file.c:182 #1: ffff888108ab2c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888119d30008 (kn->active#9){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888119d30008 (kn->active#9){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff88811e260198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline] #3: ffff88811e260198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 3 locks held by kworker/0:4/5226: 6 locks held by kworker/1:3/5230: #0: ffff8881056ec148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc900021dfca0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff88810a384198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810a384198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899 #3: ffff88811d9ad198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff88811d9ad198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9e0 drivers/usb/core/hub.c:2336 #4: ffff88811f4b6160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88811f4b6160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline] #4: ffff88811f4b6160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1302 #5: ffff888113375238 (&ssp->srcu_sup->srcu_barrier_mutex){+.+.}-{4:4}, at: srcu_barrier+0xa6/0x7a0 kernel/rcu/srcutree.c:1725 4 locks held by udevd/5516: #0: ffff888133ce51c8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12d0 fs/seq_file.c:182 #1: ffff88810ee87488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888114c571e8 (kn->active#9){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888114c571e8 (kn->active#9){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff88811d9ad198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline] #3: ffff88811d9ad198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 5 locks held by kworker/1:5/5541: #0: ffff8881056ec148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000427fca0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff88810a39c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810a39c198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899 #3: ffff88811e263198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff88811e263198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9e0 drivers/usb/core/hub.c:2336 #4: ffff88811fc71160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88811fc71160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline] #4: ffff88811fc71160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1302 4 locks held by kworker/1:6/5733: #0: ffff8881056ec148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9001202fca0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff888109f6c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff888109f6c198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899 #3: ffff88811e260198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff88811e260198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9e0 drivers/usb/core/hub.c:2336 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x133/0x180 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xe66/0x1180 kernel/hung_task.c:515 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: usb_hub_wq hub_event RIP: 0010:hlock_class kernel/locking/lockdep.c:246 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4854 [inline] RIP: 0010:__lock_acquire+0x212/0x2890 kernel/locking/lockdep.c:5187 Code: 1f 00 00 09 d0 41 89 46 20 8b 84 24 c0 00 00 00 41 89 46 24 4c 89 c8 25 ff 1f 00 00 48 0f a3 05 44 a0 4c 0d 0f 83 db 05 00 00 <48> 8d 04 80 48 8d 04 80 48 8d 04 c5 a0 31 a8 8e 0f b6 98 c4 00 00 RSP: 0018:ffffc900000aea28 EFLAGS: 00000003 RAX: 000000000000002c RBX: 0000000000008000 RCX: 0000000000000000 RDX: 000000000000002c RSI: 0000000000000000 RDI: ffff8881f563d130 RBP: 0000000000000005 R08: 0000000000080000 R09: 000000000000002c R10: ffffffff8aa48bd7 R11: ffff888101ab27e8 R12: ffff888101ab1d40 R13: ffff8881f563d130 R14: ffff888101ab28b0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888268bf5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9c6e8656c0 CR3: 0000000117752000 CR4: 00000000003506f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 local_trylock_acquire include/linux/local_lock_internal.h:48 [inline] ___slab_alloc+0x99d/0x1ca0 mm/slub.c:4521 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __kmalloc_cache_noprof+0x3d6/0x7e0 mm/slub.c:5771 kmalloc_noprof include/linux/slab.h:957 [inline] dummy_urb_enqueue+0xa3/0x920 drivers/usb/gadget/udc/dummy_hcd.c:1273 usb_hcd_submit_urb+0x25b/0x1cf0 drivers/usb/core/hcd.c:1546 usb_submit_urb+0x899/0x1970 drivers/usb/core/urb.c:587 ath6kl_usb_post_recv_transfers.constprop.0+0x201/0x400 drivers/net/wireless/ath/ath6kl/usb.c:450 ath6kl_usb_start_recv_pipes drivers/net/wireless/ath/ath6kl/usb.c:498 [inline] hif_start drivers/net/wireless/ath/ath6kl/usb.c:703 [inline] ath6kl_usb_power_on+0x8e/0x160 drivers/net/wireless/ath/ath6kl/usb.c:1062 ath6kl_hif_power_on drivers/net/wireless/ath/ath6kl/hif-ops.h:136 [inline] ath6kl_core_init+0x17e/0x11b0 drivers/net/wireless/ath/ath6kl/core.c:97 ath6kl_usb_probe+0xcee/0x1440 drivers/net/wireless/ath/ath6kl/usb.c:1168 usb_probe_interface+0x303/0xa80 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:581 [inline] really_probe+0x241/0xb20 drivers/base/dd.c:659 __driver_probe_device+0x1de/0x470 drivers/base/dd.c:801 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831 __device_attach_driver+0x1df/0x350 drivers/base/dd.c:959 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4e0 drivers/base/dd.c:1031 device_initial_probe+0xaa/0xc0 drivers/base/dd.c:1086 bus_probe_device+0x64/0x150 drivers/base/bus.c:574 device_add+0x116e/0x1980 drivers/base/core.c:3689 usb_set_configuration+0x1187/0x1e50 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:581 [inline] really_probe+0x241/0xb20 drivers/base/dd.c:659 __driver_probe_device+0x1de/0x470 drivers/base/dd.c:801 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831 __device_attach_driver+0x1df/0x350 drivers/base/dd.c:959 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4e0 drivers/base/dd.c:1031 device_initial_probe+0xaa/0xc0 drivers/base/dd.c:1086 bus_probe_device+0x64/0x150 drivers/base/bus.c:574 device_add+0x116e/0x1980 drivers/base/core.c:3689 usb_new_device+0xd07/0x1a90 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+0x31bf/0x5420 drivers/usb/core/hub.c:5953 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246