INFO: task kworker/0:6:5876 blocked for more than 143 seconds. Not tainted 6.14.0-rc6-syzkaller-00016-g0fed89a961ea #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:6 state:D stack:18800 pid:5876 tgid:5876 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 usb_kill_urb+0x1c9/0x300 drivers/usb/core/urb.c:713 usb_start_wait_urb+0x1b0/0x520 drivers/usb/core/message.c:65 usb_internal_control_msg drivers/usb/core/message.c:103 [inline] usb_control_msg+0x2b1/0x4c0 drivers/usb/core/message.c:154 get_bMaxPacketSize0 drivers/usb/core/hub.c:4817 [inline] hub_port_init+0x122f/0x26f0 drivers/usb/core/hub.c:5078 hub_port_connect drivers/usb/core/hub.c:5462 [inline] hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] port_event drivers/usb/core/hub.c:5833 [inline] hub_event+0x2962/0x5150 drivers/usb/core/hub.c:5915 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task kworker/0:9:7043 blocked for more than 143 seconds. Not tainted 6.14.0-rc6-syzkaller-00016-g0fed89a961ea #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:9 state:D stack:18968 pid:7043 tgid:7043 ppid:2 task_flags:0x4208160 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 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+0x25f7/0x5150 drivers/usb/core/hub.c:5915 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by getty/5588: #0: ffff88814d5950a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211 5 locks held by kworker/0:6/5876: #0: ffff888021694548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888021694548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x98b/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+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffff888146786190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #2: ffff888146786190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5861 #3: ffff888146791510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] #3: ffff888146791510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5430 [inline] #3: ffff888146791510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] #3: ffff888146791510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5833 [inline] #3: ffff888146791510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x25b9/0x5150 drivers/usb/core/hub.c:5915 #4: ffff888146759368 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5431 [inline] #4: ffff888146759368 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] #4: ffff888146759368 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5833 [inline] #4: ffff888146759368 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x25f7/0x5150 drivers/usb/core/hub.c:5915 5 locks held by kworker/0:9/7043: #0: ffff888021694548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888021694548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc900037c7c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900037c7c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffff888146ba4190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #2: ffff888146ba4190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5861 #3: ffff888146773510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] #3: ffff888146773510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5430 [inline] #3: ffff888146773510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] #3: ffff888146773510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5833 [inline] #3: ffff888146773510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x25b9/0x5150 drivers/usb/core/hub.c:5915 #4: ffff888146759368 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5431 [inline] #4: ffff888146759368 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] #4: ffff888146759368 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5833 [inline] #4: ffff888146759368 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x25f7/0x5150 drivers/usb/core/hub.c:5915 5 locks held by kworker/u8:4/24054: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-00016-g0fed89a961ea #0 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+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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