syzbot

INFO: task kworker/1:2:971 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc6-syzkaller-00202-ga29967be967e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:2     state:D stack:26768 pid:971   tgid:971   ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6857
 usb_kill_urb.part.0+0x1ca/0x250 drivers/usb/core/urb.c:713
 usb_kill_urb+0x83/0xa0 drivers/usb/core/urb.c:702
 usb_start_wait_urb+0x255/0x4c0 drivers/usb/core/message.c:65
 usb_internal_control_msg drivers/usb/core/message.c:103 [inline]
 usb_control_msg+0x327/0x4b0 drivers/usb/core/message.c:154
 get_bMaxPacketSize0.constprop.0+0xd0/0x1f0 drivers/usb/core/hub.c:4817
 hub_port_init+0x693/0x3a40 drivers/usb/core/hub.c:5013
 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+0x2b4f/0x4e10 drivers/usb/core/hub.c:5915
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746
5 locks held by kworker/1:2/971:
 #0: ffff88801b1e2148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213
 #1: ffffc900040ffd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214
 #2: ffff888029e12190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
 #2: ffff888029e12190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c1/0x4e10 drivers/usb/core/hub.c:5861
 #3: ffff888029e16510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline]
 #3: ffff888029e16510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5430 [inline]
 #3: ffff888029e16510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5673 [inline]
 #3: ffff888029e16510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5833 [inline]
 #3: ffff888029e16510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x27ec/0x4e10 drivers/usb/core/hub.c:5915
 #4: ffff888029067a68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5431 [inline]
 #4: ffff888029067a68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5673 [inline]
 #4: ffff888029067a68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5833 [inline]
 #4: ffff888029067a68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2815/0x4e10 drivers/usb/core/hub.c:5915
2 locks held by getty/5581:
 #0: ffff88814da9c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-00202-ga29967be967e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __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:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
 watchdog+0xf62/0x12b0 kernel/hung_task.c:399
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
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+0x1a/0x20 drivers/acpi/processor_idle.c:111