INFO: task kworker/1:9:13298 blocked for more than 143 seconds. Not tainted 6.6.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:9 state:D stack:23520 pid:13298 ppid:2 flags:0x00004000 Workqueue: events console_callback Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0xc79/0x30a0 kernel/sched/core.c:6695 schedule+0xe7/0x1b0 kernel/sched/core.c:6771 schedule_timeout+0x278/0x2c0 kernel/time/timer.c:2143 ___down_common kernel/locking/semaphore.c:225 [inline] __down_common+0x327/0x6c0 kernel/locking/semaphore.c:246 down+0x74/0xa0 kernel/locking/semaphore.c:63 console_lock+0x96/0x150 kernel/printk/printk.c:2652 console_callback+0x63/0x4c0 drivers/tty/vt/vt.c:2933 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 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:304 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff87eac820 (rcu_read_lock ){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:303 [inline] ){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:749 [inline] ){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613 2 locks held by getty/2449: #0: ffff888112e900a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc5/0x1480 drivers/tty/n_tty.c:2206 5 locks held by kworker/1:2/2493: 3 locks held by kworker/1:3/7920: 3 locks held by kworker/0:5/8088: 5 locks held by kworker/1:8/8501: 3 locks held by kworker/1:0/11751: 2 locks held by kworker/1:9/13298: #0: ffff888100070d38 ((wq_completion)events ){+.+.}-{0:0} , at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc9000166fd80 (console_work){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 3 locks held by kworker/0:14/15942: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.6.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x380 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x26c/0x2d0 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+0x33c/0x440 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:304 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2493 Comm: kworker/1:2 Not tainted 6.6.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Workqueue: usb_hub_wq hub_event RIP: 0010:io_serial_in+0x87/0xa0 drivers/tty/serial/8250/8250_port.c:418 Code: ed c8 fe 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 16 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c c3 e8 6c 59 15 ff eb a6 e8 c5 59 15 ff eb e3 RSP: 0018:ffffc9000147f0e8 EFLAGS: 00000002 RAX: dffffc0000000060 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: ffffffff82848600 RDI: ffffffff8c156ee0 RBP: ffffffff8c156ea0 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 205d393254202020 R12: 0000000000000000 R13: 0000000000000020 R14: fffffbfff182ae2e R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffeab61c848 CR3: 000000013d416000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:117 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:139 [inline] wait_for_lsr+0xd7/0x180 drivers/tty/serial/8250/8250_port.c:2086 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline] serial8250_console_write+0xce5/0x1060 drivers/tty/serial/8250/8250_port.c:3449 console_emit_next_record kernel/printk/printk.c:2910 [inline] console_flush_all+0x4eb/0xfb0 kernel/printk/printk.c:2966 console_unlock+0x10c/0x260 kernel/printk/printk.c:3035 vprintk_emit+0x17f/0x5f0 kernel/printk/printk.c:2307 dev_vprintk_emit drivers/base/core.c:4849 [inline] dev_printk_emit+0xfb/0x140 drivers/base/core.c:4860 __dev_printk+0xf5/0x270 drivers/base/core.c:4872 _dev_notice+0xe5/0x120 drivers/base/core.c:4917 usb_parse_configuration drivers/usb/core/config.c:734 [inline] usb_get_configuration+0xab7/0x5640 drivers/usb/core/config.c:944 usb_enumerate_device drivers/usb/core/hub.c:2421 [inline] usb_new_device+0x1115/0x1960 drivers/usb/core/hub.c:2559 hub_port_connect drivers/usb/core/hub.c:5440 [inline] hub_port_connect_change drivers/usb/core/hub.c:5580 [inline] port_event drivers/usb/core/hub.c:5740 [inline] hub_event+0x2e62/0x4f30 drivers/usb/core/hub.c:5822 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 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:304