INFO: task kworker/1:6:17420 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:6     state:D stack:21208 pid:17420 tgid:17420 ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 usb_kill_urb+0x1be/0x2d0 drivers/usb/core/urb.c:712
 usb_start_wait_urb+0x18c/0x4c0 drivers/usb/core/message.c:65
 usb_internal_control_msg drivers/usb/core/message.c:103 [inline]
 usb_control_msg+0x232/0x3e0 drivers/usb/core/message.c:154
 get_bMaxPacketSize0 drivers/usb/core/hub.c:4850 [inline]
 hub_port_init+0xbf9/0x2800 drivers/usb/core/hub.c:5046
 hub_port_connect drivers/usb/core/hub.c:5495 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
 port_event drivers/usb/core/hub.c:5870 [inline]
 hub_event+0x2532/0x4a20 drivers/usb/core/hub.c:5952
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by klogd/5198:
 #0: ffff8880b883a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646
2 locks held by getty/5598:
 #0: ffff8880338150a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by kworker/1:6/17420:
 #0: ffff8880212e0548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff8880212e0548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc900048afbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc900048afbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffff8881453ec198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
 #2: ffff8881453ec198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
 #3: ffff888145b38518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3251 [inline]
 #3: ffff888145b38518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5463 [inline]
 #3: ffff888145b38518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
 #3: ffff888145b38518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline]
 #3: ffff888145b38518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21b8/0x4a20 drivers/usb/core/hub.c:5952
 #4: ffff8881457a7968 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
 #4: ffff8881457a7968 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
 #4: ffff8881457a7968 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline]
 #4: ffff8881457a7968 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21e5/0x4a20 drivers/usb/core/hub.c:5952
5 locks held by kworker/1:3/1525:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
 watchdog+0xf60/0xfa0 kernel/hung_task.c:495
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 28091 Comm: kworker/1:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: 84 b0 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 1c 25 16 fd 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 87 f5 27 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc900044b7330 EFLAGS: 00000002
RAX: 0000000000000032 RBX: 0000000000000032 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: ffff888141758237 R09: 1ffff110282eb046
R10: dffffc0000000000 R11: ffffffff850dfa10 R12: dffffc0000000000
R13: ffffffff9957e8e8 R14: ffffffff99871040 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888126496000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562d57804660 CR3: 000000007853e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 serial_port_out include/linux/serial_core.h:798 [inline]
 serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3246 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
 serial8250_console_write+0x1410/0x1ba0 drivers/tty/serial/8250/8250_port.c:3396
 console_emit_next_record kernel/printk/printk.c:3111 [inline]
 console_flush_all+0x6f0/0xb10 kernel/printk/printk.c:3199
 __console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
 console_unlock+0xbb/0x190 kernel/printk/printk.c:3298
 vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423
 _printk+0xcf/0x120 kernel/printk/printk.c:2448
 m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline]
 m920x_rc_query+0x2f6/0x830 drivers/media/usb/dvb-usb/m920x.c:-1
 legacy_dvb_usb_read_remote_control+0xfd/0x470 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>