INFO: task kworker/0:2:978 blocked for more than 143 seconds. Not tainted 6.14.0-rc3-syzkaller-00060-g6537cfb395f3 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:2 state:D stack:19224 pid:978 tgid:978 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:3236 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 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/30: #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 5 locks held by kworker/0:2/978: #0: ffff8881446e2948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff8881446e2948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3317 #1: ffffc90003cefc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90003cefc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3317 #2: ffff888029a44190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #2: ffff888029a44190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5861 #3: ffff888029a47510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] #3: ffff888029a47510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5430 [inline] #3: ffff888029a47510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] #3: ffff888029a47510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5833 [inline] #3: ffff888029a47510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x25b9/0x5150 drivers/usb/core/hub.c:5915 #4: ffff888029565a68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5431 [inline] #4: ffff888029565a68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] #4: ffff888029565a68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5833 [inline] #4: ffff888029565a68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x25f7/0x5150 drivers/usb/core/hub.c:5915 2 locks held by getty/5596: #0: ffff88814c7de0a0 (&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 7 locks held by kworker/1:5/30086: #0: ffff8880b863e958 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:606 #1: ffff8880b8728948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41d/0x7a0 kernel/sched/psi.c:987 #2: ffff8880b872b458 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1046 [inline] #2: ffff8880b872b458 (&base->lock){-.-.}-{2:2}, at: add_timer_on+0x223/0x600 kernel/time/timer.c:1361 #3: ffffffff9a8bdf90 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x17f/0x580 lib/debugobjects.c:818 #4: ffffffff8ea14ac0 (console_owner){-.-.}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:342 [inline] #4: ffffffff8ea14ac0 (console_owner){-.-.}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:304 [inline] #4: ffffffff8ea14ac0 (console_owner){-.-.}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline] #4: ffffffff8ea14ac0 (console_owner){-.-.}-{0:0}, at: console_flush_all+0x1a3/0xeb0 kernel/printk/printk.c:3187 #5: ffffffff8ea14a78 (console_owner_lock){-.-.}-{2:2}, at: console_lock_spinning_disable_and_check+0x86/0x190 kernel/printk/printk.c:1963 #6: ffffffff9a993058 (&port_lock_key){-.-.}-{3:3}, at: uart_port_lock_irqsave include/linux/serial_core.h:715 [inline] #6: ffffffff9a993058 (&port_lock_key){-.-.}-{3:3}, at: serial8250_console_write+0x1ae/0x1e00 drivers/tty/serial/8250/8250_port.c:3424 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc3-syzkaller-00060-g6537cfb395f3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 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 CPU: 1 UID: 0 PID: 30086 Comm: kworker/1:5 Not tainted 6.14.0-rc3-syzkaller-00060-g6537cfb395f3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events legacy_dvb_usb_read_remote_control RIP: 0010:io_serial_out+0x7e/0xc0 drivers/tty/serial/8250/8250_port.c:416 Code: fc 89 e9 41 d3 e7 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 ac 2c a5 fc 44 03 3b 44 89 f0 44 89 fa ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c a7 RSP: 0018:ffffc90003d9f330 EFLAGS: 00000002 RAX: 000000000000005d RBX: ffffffff9a993080 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020 RBP: 0000000000000000 R08: ffffffff8583ce2b R09: 1ffff110049c0046 R10: dffffc0000000000 R11: ffffffff8583cde0 R12: dffffc0000000000 R13: 000000000000005d R14: 000000000000005d R15: 00000000000003f8 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b241417f28 CR3: 0000000034144000 CR4: 00000000003526f0 Call Trace: serial8250_console_write+0x1430/0x1e00 drivers/tty/serial/8250/8250_port.c:3465 console_emit_next_record kernel/printk/printk.c:3122 [inline] console_flush_all+0x869/0xeb0 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432 _printk+0xd5/0x120 kernel/printk/printk.c:2457 m920x_rc_query+0x314/0x820 legacy_dvb_usb_read_remote_control+0x122/0x590 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 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