INFO: task kworker/1:2:2751 blocked for more than 143 seconds. Not tainted 6.8.0-rc1-syzkaller-00049-g6098d87eaf31 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:2 state:D stack:24128 pid:2751 tgid:2751 ppid:2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0xf12/0x5c00 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0xe9/0x270 kernel/sched/core.c:6817 usb_kill_urb.part.0+0x1c6/0x250 drivers/usb/core/urb.c:713 usb_kill_urb+0x83/0xa0 drivers/usb/core/urb.c:702 usb_start_wait_urb+0x251/0x4c0 drivers/usb/core/message.c:65 usb_internal_control_msg drivers/usb/core/message.c:103 [inline] usb_control_msg+0x327/0x4a0 drivers/usb/core/message.c:154 get_bMaxPacketSize0.constprop.0+0xa5/0x1c0 drivers/usb/core/hub.c:4750 hub_port_init+0x68c/0x39e0 drivers/usb/core/hub.c:4946 hub_port_connect drivers/usb/core/hub.c:5394 [inline] hub_port_connect_change drivers/usb/core/hub.c:5605 [inline] port_event drivers/usb/core/hub.c:5765 [inline] hub_event+0x2b61/0x4e10 drivers/usb/core/hub.c:5847 process_one_work+0x886/0x15d0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Showing all locks held in the system: 1 lock held by rcu_preempt/17: #0: ffff8880b983ccd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:567 [inline] #0: ffff8880b983ccd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:552 1 lock held by khungtaskd/29: #0: ffffffff8d1acba0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8d1acba0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8d1acba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 2 locks held by getty/4818: #0: ffff8880293b70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc6/0x1490 drivers/tty/n_tty.c:2201 2 locks held by kworker/u4:7/27404: 5 locks held by kworker/1:2/2751: #0: ffff888019acd138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2608 #1: ffffc9001845fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2609 #2: ffff888022580190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #2: ffff888022580190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4e10 drivers/usb/core/hub.c:5793 #3: ffff888022558510 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3151 [inline] #3: ffff888022558510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5362 [inline] #3: ffff888022558510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5605 [inline] #3: ffff888022558510 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5765 [inline] #3: ffff888022558510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x27fe/0x4e10 drivers/usb/core/hub.c:5847 #4: ffff8880223d26c8 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5363 [inline] #4: ffff8880223d26c8 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5605 [inline] #4: ffff8880223d26c8 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5765 [inline] #4: ffff8880223d26c8 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x2827/0x4e10 drivers/usb/core/hub.c:5847 1 lock held by syz-executor.3/13959: #0: ffffffff8d1b82c0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x6c0 kernel/rcu/tree.c:4032 1 lock held by syz-executor.1/13995: #0: ffff88807a2601a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock_killable include/linux/mmap_lock.h:155 [inline] #0: ffff88807a2601a0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5486 [inline] #0: ffff88807a2601a0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x352/0x580 mm/memory.c:5537 4 locks held by syz-executor.1/13998: 2 locks held by syz-executor.0/13997: #0: ffff8880b983ccd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:567 [inline] #0: ffff8880b983ccd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:552 #1: ffff8880b9828a08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2d9/0x900 kernel/sched/psi.c:988 1 lock held by syz-executor.4/14007: 1 lock held by syz-executor.2/14008: 2 locks held by syz-executor.4/14011: 3 locks held by syz-executor.0/14016: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc1-syzkaller-00049-g6098d87eaf31 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x299/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf87/0x1210 kernel/hung_task.c:379 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x1b/0x20 drivers/acpi/processor_idle.c:112