INFO: task kworker/1:1:48 blocked for more than 143 seconds. Not tainted 6.14.0-syzkaller-09584-g7d06015d936c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:1 state:D stack:24192 pid:48 tgid:48 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:664 [inline] __mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:732 hub_port_connect drivers/usb/core/hub.c:5431 [inline] hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] port_event drivers/usb/core/hub.c:5833 [inline] hub_event+0x24cd/0x50f0 drivers/usb/core/hub.c:5915 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8ed3a2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3a2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3a2a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6761 5 locks held by kworker/1:1/48: #0: ffff8880216a0548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8880216a0548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000b97c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000b97c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff888146340190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #2: ffff888146340190 (&dev->mutex){....}-{4:4}, at: hub_event+0x200/0x50f0 drivers/usb/core/hub.c:5861 #3: ffff8880294d7510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] #3: ffff8880294d7510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5430 [inline] #3: ffff8880294d7510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] #3: ffff8880294d7510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5833 [inline] #3: ffff8880294d7510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2494/0x50f0 drivers/usb/core/hub.c:5915 #4: ffff888027569768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5431 [inline] #4: ffff888027569768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] #4: ffff888027569768 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5833 [inline] #4: ffff888027569768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x24cd/0x50f0 drivers/usb/core/hub.c:5915 2 locks held by getty/5599: #0: ffff888035e9a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x53d/0x16b0 drivers/tty/n_tty.c:2211 4 locks held by udevd/5833: #0: ffff88804f86d1c8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb4/0xda0 fs/seq_file.c:182 #1: ffff88807ce0b888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 #2: ffff8880318053c8 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155 #3: ffff88805df19190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff88805df19190 (&dev->mutex){....}-{4:4}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2730 5 locks held by kworker/1:3/5843: #0: ffff8880216a0548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8880216a0548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc900041cfc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900041cfc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff8880294d0190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #2: ffff8880294d0190 (&dev->mutex){....}-{4:4}, at: hub_event+0x200/0x50f0 drivers/usb/core/hub.c:5861 #3: ffff888146327510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] #3: ffff888146327510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5430 [inline] #3: ffff888146327510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] #3: ffff888146327510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5833 [inline] #3: ffff888146327510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2494/0x50f0 drivers/usb/core/hub.c:5915 #4: ffff888027569768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5431 [inline] #4: ffff888027569768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] #4: ffff888027569768 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5833 [inline] #4: ffff888027569768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x24cd/0x50f0 drivers/usb/core/hub.c:5915 6 locks held by kworker/0:5/5934: #0: ffff8880216a0548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8880216a0548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000448fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000448fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff88814576b190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #2: ffff88814576b190 (&dev->mutex){....}-{4:4}, at: hub_event+0x200/0x50f0 drivers/usb/core/hub.c:5861 #3: ffff88805df19190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff88805df19190 (&dev->mutex){....}-{4:4}, at: __device_attach+0x90/0x530 drivers/base/dd.c:1005 #4: ffff88802566e160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #4: ffff88802566e160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x90/0x530 drivers/base/dd.c:1005 #5: ffffffff8ebe2f70 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0x142/0x300 kernel/umh.c:214 4 locks held by udevd/7566: #0: ffff888033c0e418 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb4/0xda0 fs/seq_file.c:182 #1: ffff888029569488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 #2: ffff88805d14c968 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155 #3: ffff88805d633190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff88805d633190 (&dev->mutex){....}-{4:4}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2730 1 lock held by syz.1.670/8323: #0: ffff88814576b190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #0: ffff88814576b190 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x155/0x790 drivers/usb/core/devio.c:1054 5 locks held by kworker/1:8/8471: #0: ffff8880216a0548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8880216a0548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9001037fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9001037fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff888145753190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #2: ffff888145753190 (&dev->mutex){....}-{4:4}, at: hub_event+0x200/0x50f0 drivers/usb/core/hub.c:5861 #3: ffff88805d633190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff88805d633190 (&dev->mutex){....}-{4:4}, at: __device_attach+0x90/0x530 drivers/base/dd.c:1005 #4: ffff888144ae5a78 (&(&priv->bus_notifier)->rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x53/0x90 kernel/notifier.c:379 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-syzkaller-09584-g7d06015d936c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111