syzbot

=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
syzkaller #0 Tainted: G             L     
-----------------------------------------------------
syz.3.10721/2262 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff88804791d468 (&tty->flow.lock){....}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline]
ffff88804791d468 (&tty->flow.lock){....}-{3:3}, at: stop_tty+0x2f/0x150 drivers/tty/tty_io.c:765

and this task is already holding:
ffffffff8effb7b8 (kbd_event_lock){..-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline]
ffffffff8effb7b8 (kbd_event_lock){..-.}-{3:3}, at: class_spinlock_constructor include/linux/spinlock.h:586 [inline]
ffffffff8effb7b8 (kbd_event_lock){..-.}-{3:3}, at: kbd_event+0xd6/0x40d0 drivers/tty/vt/keyboard.c:1510
which would create a new lock dependency:
 (kbd_event_lock){..-.}-{3:3} -> (&tty->flow.lock){....}-{3:3}

but this new dependency connects a SOFTIRQ-irq-safe lock:
 (kbd_event_lock){..-.}-{3:3}

... which became SOFTIRQ-irq-safe at:
  lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
  __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
  _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
  spin_lock include/linux/spinlock.h:341 [inline]
  class_spinlock_constructor include/linux/spinlock.h:586 [inline]
  kbd_event+0xd6/0x40d0 drivers/tty/vt/keyboard.c:1510
  input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
  input_pass_values+0x288/0x890 drivers/input/input.c:128
  input_event_dispose+0x3e5/0x6b0 drivers/input/input.c:353
  input_event+0x89/0xe0 drivers/input/input.c:396
  hidinput_hid_event+0x1487/0x1e60 drivers/hid/hid-input.c:1747
  hid_process_event+0x4be/0x620 drivers/hid/hid-core.c:1565
  hid_process_report drivers/hid/hid-core.c:1713 [inline]
  hid_report_raw_event+0xe8f/0x1720 drivers/hid/hid-core.c:2074
  __hid_input_report drivers/hid/hid-core.c:2144 [inline]
  hid_input_report+0x44b/0x580 drivers/hid/hid-core.c:2166
  hid_irq_in+0x47e/0x6d0 drivers/hid/usbhid/hid-core.c:286
  __usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1657
  dummy_timer+0xbbd/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1995
  __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
  __hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
  hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866
  handle_softirqs+0x22a/0x870 kernel/softirq.c:622
  __do_softirq kernel/softirq.c:656 [inline]
  invoke_softirq kernel/softirq.c:496 [inline]
  __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
  irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
  sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
  asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
  console_flush_one_record arch/x86/include/asm/irqflags.h:-1 [inline]
  console_flush_all+0x801/0xb20 kernel/printk/printk.c:3343
  __console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
  console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
  vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
  _printk+0xdd/0x130 kernel/printk/printk.c:2504
  legacy_dvb_usb_read_remote_control+0x37f/0x450 drivers/media/usb/dvb-usb/dvb-usb-remote.c:124
  process_one_work kernel/workqueue.c:3275 [inline]
  process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
  worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
  kthread+0x388/0x470 kernel/kthread.c:436
  ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

to a SOFTIRQ-irq-unsafe lock:
 (tasklist_lock){.+.+}-{3:3}

... which became SOFTIRQ-irq-unsafe at:
...
  lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
  __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline]
  _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
  __do_wait+0xde/0x740 kernel/exit.c:1678
  do_wait+0x1e7/0x540 kernel/exit.c:1722
  kernel_wait+0xd6/0x1c0 kernel/exit.c:1898
  call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
  call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
  process_one_work kernel/workqueue.c:3275 [inline]
  process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
  worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
  kthread+0x388/0x470 kernel/kthread.c:436
  ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

other info that might help us debug this:

Chain exists of:
  kbd_event_lock --> &tty->flow.lock --> tasklist_lock

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(tasklist_lock);
                               local_irq_disable();
                               lock(kbd_event_lock);
                               lock(&tty->flow.lock);
  <Interrupt>
    lock(kbd_event_lock);

 *** DEADLOCK ***

5 locks held by syz.3.10721/2262:
 #0: ffff88802b9ad118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_write+0x1ae/0x4c0 drivers/input/evdev.c:511
 #1: ffff88802b8dd230 (&dev->event_lock#2){..-.}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline]
 #1: ffff88802b8dd230 (&dev->event_lock#2){..-.}-{3:3}, at: input_inject_event+0xa5/0x340 drivers/input/input.c:419
 #2: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #2: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #2: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 #2: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: input_inject_event+0xb6/0x340 drivers/input/input.c:420
 #3: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #3: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #3: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 #3: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: input_pass_values+0x8d/0x890 drivers/input/input.c:119
 #4: ffffffff8effb7b8 (kbd_event_lock){..-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline]
 #4: ffffffff8effb7b8 (kbd_event_lock){..-.}-{3:3}, at: class_spinlock_constructor include/linux/spinlock.h:586 [inline]
 #4: ffffffff8effb7b8 (kbd_event_lock){..-.}-{3:3}, at: kbd_event+0xd6/0x40d0 drivers/tty/vt/keyboard.c:1510

the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (kbd_event_lock){..-.}-{3:3} {
   IN-SOFTIRQ-W at:
                    lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                    __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
                    _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
                    spin_lock include/linux/spinlock.h:341 [inline]
                    class_spinlock_constructor include/linux/spinlock.h:586 [inline]
                    kbd_event+0xd6/0x40d0 drivers/tty/vt/keyboard.c:1510
                    input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
                    input_pass_values+0x288/0x890 drivers/input/input.c:128
                    input_event_dispose+0x3e5/0x6b0 drivers/input/input.c:353
                    input_event+0x89/0xe0 drivers/input/input.c:396
                    hidinput_hid_event+0x1487/0x1e60 drivers/hid/hid-input.c:1747
                    hid_process_event+0x4be/0x620 drivers/hid/hid-core.c:1565
                    hid_process_report drivers/hid/hid-core.c:1713 [inline]
                    hid_report_raw_event+0xe8f/0x1720 drivers/hid/hid-core.c:2074
                    __hid_input_report drivers/hid/hid-core.c:2144 [inline]
                    hid_input_report+0x44b/0x580 drivers/hid/hid-core.c:2166
                    hid_irq_in+0x47e/0x6d0 drivers/hid/usbhid/hid-core.c:286
                    __usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1657
                    dummy_timer+0xbbd/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1995
                    __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
                    __hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
                    hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866
                    handle_softirqs+0x22a/0x870 kernel/softirq.c:622
                    __do_softirq kernel/softirq.c:656 [inline]
                    invoke_softirq kernel/softirq.c:496 [inline]
                    __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
                    irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
                    instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
                    sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
                    asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
                    console_flush_one_record arch/x86/include/asm/irqflags.h:-1 [inline]
                    console_flush_all+0x801/0xb20 kernel/printk/printk.c:3343
                    __console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
                    console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
                    vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
                    _printk+0xdd/0x130 kernel/printk/printk.c:2504
                    legacy_dvb_usb_read_remote_control+0x37f/0x450 drivers/media/usb/dvb-usb/dvb-usb-remote.c:124
                    process_one_work kernel/workqueue.c:3275 [inline]
                    process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
                    worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
                    kthread+0x388/0x470 kernel/kthread.c:436
                    ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
                    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
   INITIAL USE at:
                   lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
                   _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
                   class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline]
                   vt_reset_unicode+0x2b/0x1a0 drivers/tty/vt/keyboard.c:2126
                   reset_vc+0x68/0x1b0 drivers/tty/vt/vt_ioctl.c:966
                   vc_init+0x70/0x4a0 drivers/tty/vt/vt.c:3721
                   con_init+0x377/0x6a0 drivers/tty/vt/vt.c:3787
                   console_init+0x10b/0x4d0 kernel/printk/printk.c:4407
                   start_kernel+0x22b/0x3d0 init/main.c:1147
                   x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
                   x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
                   common_startup_64+0x13e/0x147
 }
 ... key      at: [<ffffffff8effb7b8>] kbd_event_lock+0x18/0xa0 keyboard.c:-1

the dependencies between the lock to be acquired
 and SOFTIRQ-irq-unsafe lock:
   -> (tasklist_lock){.+.+}-{3:3} {
      HARDIRQ-ON-R at:
                          lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                          __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline]
                          _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
                          __do_wait+0xde/0x740 kernel/exit.c:1678
                          do_wait+0x1e7/0x540 kernel/exit.c:1722
                          kernel_wait+0xd6/0x1c0 kernel/exit.c:1898
                          call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
                          call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
                          process_one_work kernel/workqueue.c:3275 [inline]
                          process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
                          worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
                          kthread+0x388/0x470 kernel/kthread.c:436
                          ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
                          ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
      SOFTIRQ-ON-R at:
                          lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                          __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline]
                          _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
                          __do_wait+0xde/0x740 kernel/exit.c:1678
                          do_wait+0x1e7/0x540 kernel/exit.c:1722
                          kernel_wait+0xd6/0x1c0 kernel/exit.c:1898
                          call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
                          call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
                          process_one_work kernel/workqueue.c:3275 [inline]
                          process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
                          worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
                          kthread+0x388/0x470 kernel/kthread.c:436
                          ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
                          ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
      INITIAL USE at:
                         lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                         __raw_write_lock_irq include/linux/rwlock_api_smp.h:211 [inline]
                         _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326
                         copy_process+0x247a/0x3cf0 kernel/fork.c:2369
                         kernel_clone+0x248/0x8e0 kernel/fork.c:2654
                         user_mode_thread+0x110/0x180 kernel/fork.c:2730
                         rest_init+0x23/0x300 init/main.c:725
                         start_kernel+0x385/0x3d0 init/main.c:1210
                         x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
                         x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
                         common_startup_64+0x13e/0x147
      INITIAL READ USE at:
                              lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                              __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline]
                              _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
                              __do_wait+0xde/0x740 kernel/exit.c:1678
                              do_wait+0x1e7/0x540 kernel/exit.c:1722
                              kernel_wait+0xd6/0x1c0 kernel/exit.c:1898
                              call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
                              call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
                              process_one_work kernel/workqueue.c:3275 [inline]
                              process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
                              worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
                              kthread+0x388/0x470 kernel/kthread.c:436
                              ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
                              ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
    }
    ... key      at: [<ffffffff8e40c058>] tasklist_lock+0x18/0x40
    ... acquired at:
   __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline]
   _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
   send_sigio+0x101/0x370 fs/fcntl.c:932
   dnotify_handle_event+0x169/0x440 fs/notify/dnotify/dnotify.c:113
   fsnotify_handle_event fs/notify/fsnotify.c:327 [inline]
   send_to_group fs/notify/fsnotify.c:375 [inline]
   fsnotify+0x1831/0x1ae0 fs/notify/fsnotify.c:592
   fsnotify_name include/linux/fsnotify.h:55 [inline]
   fsnotify_dirent include/linux/fsnotify.h:61 [inline]
   fsnotify_create include/linux/fsnotify.h:323 [inline]
   open_last_lookups fs/namei.c:4586 [inline]
   path_openat+0x15c2/0x3860 fs/namei.c:4827
   do_file_open+0x23e/0x4a0 fs/namei.c:4859
   do_sys_openat2+0x113/0x200 fs/open.c:1366
   do_sys_open fs/open.c:1372 [inline]
   __do_sys_openat fs/open.c:1388 [inline]
   __se_sys_openat fs/open.c:1383 [inline]
   __x64_sys_openat+0x138/0x170 fs/open.c:1383
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

  -> (&f_owner->lock){....}-{3:3} {
     INITIAL USE at:
                       lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                       __raw_write_lock_irq include/linux/rwlock_api_smp.h:211 [inline]
                       _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326
                       __f_setown+0x67/0x370 fs/fcntl.c:136
                       generic_add_lease fs/locks.c:1908 [inline]
                       generic_setlease+0xacf/0xff0 fs/locks.c:1984
                       do_fcntl_add_lease+0x35e/0x470 fs/locks.c:2086
                       fcntl_setlease+0x123/0x180 fs/locks.c:2111
                       do_fcntl+0x8b3/0x1a20 fs/fcntl.c:535
                       __do_sys_fcntl fs/fcntl.c:602 [inline]
                       __se_sys_fcntl+0xc8/0x150 fs/fcntl.c:587
                       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                       do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
                       entry_SYSCALL_64_after_hwframe+0x77/0x7f
     INITIAL READ USE at:
                            lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                            __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline]
                            _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236
                            send_sigio+0x38/0x370 fs/fcntl.c:918
                            kill_fasync_rcu fs/fcntl.c:1144 [inline]
                            kill_fasync+0x24d/0x4d0 fs/fcntl.c:1159
                            lease_break_callback+0x26/0x30 fs/locks.c:577
                            __break_lease+0x81c/0x1e80 fs/locks.c:1657
                            break_lease include/linux/filelock.h:484 [inline]
                            do_dentry_open+0x1010/0x14e0 fs/open.c:940
                            vfs_open+0x3b/0x340 fs/open.c:1081
                            do_open fs/namei.c:4671 [inline]
                            path_openat+0x2e08/0x3860 fs/namei.c:4830
                            do_file_open+0x23e/0x4a0 fs/namei.c:4859
                            do_sys_openat2+0x113/0x200 fs/open.c:1366
                            do_sys_open fs/open.c:1372 [inline]
                            __do_sys_open fs/open.c:1380 [inline]
                            __se_sys_open fs/open.c:1376 [inline]
                            __x64_sys_open+0x11e/0x150 fs/open.c:1376
                            do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                            do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
                            entry_SYSCALL_64_after_hwframe+0x77/0x7f
   }
   ... key      at: [<ffffffff9a2e91e0>] file_f_owner_allocate.__key+0x0/0x20
   ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline]
   _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236
   send_sigio+0x38/0x370 fs/fcntl.c:918
   kill_fasync_rcu fs/fcntl.c:1144 [inline]
   kill_fasync+0x24d/0x4d0 fs/fcntl.c:1159
   lease_break_callback+0x26/0x30 fs/locks.c:577
   __break_lease+0x81c/0x1e80 fs/locks.c:1657
   break_lease include/linux/filelock.h:484 [inline]
   do_dentry_open+0x1010/0x14e0 fs/open.c:940
   vfs_open+0x3b/0x340 fs/open.c:1081
   do_open fs/namei.c:4671 [inline]
   path_openat+0x2e08/0x3860 fs/namei.c:4830
   do_file_open+0x23e/0x4a0 fs/namei.c:4859
   do_sys_openat2+0x113/0x200 fs/open.c:1366
   do_sys_open fs/open.c:1372 [inline]
   __do_sys_open fs/open.c:1380 [inline]
   __se_sys_open fs/open.c:1376 [inline]
   __x64_sys_open+0x11e/0x150 fs/open.c:1376
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

 -> (&new->fa_lock){....}-{3:3} {
    INITIAL USE at:
                     lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                     __raw_write_lock_irq include/linux/rwlock_api_smp.h:211 [inline]
                     _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326
                     fasync_insert_entry+0xc3/0x270 fs/fcntl.c:1059
                     lease_setup+0x86/0x110 fs/locks.c:592
                     generic_add_lease fs/locks.c:1908 [inline]
                     generic_setlease+0xacf/0xff0 fs/locks.c:1984
                     do_fcntl_add_lease+0x35e/0x470 fs/locks.c:2086
                     fcntl_setlease+0x123/0x180 fs/locks.c:2111
                     do_fcntl+0x8b3/0x1a20 fs/fcntl.c:535
                     __do_sys_fcntl fs/fcntl.c:602 [inline]
                     __se_sys_fcntl+0xc8/0x150 fs/fcntl.c:587
                     do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                     do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
                     entry_SYSCALL_64_after_hwframe+0x77/0x7f
    INITIAL READ USE at:
                          lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                          __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline]
                          _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236
                          kill_fasync_rcu fs/fcntl.c:1135 [inline]
                          kill_fasync+0x199/0x4d0 fs/fcntl.c:1159
                          lease_break_callback+0x26/0x30 fs/locks.c:577
                          __break_lease+0x81c/0x1e80 fs/locks.c:1657
                          break_lease include/linux/filelock.h:484 [inline]
                          do_dentry_open+0x1010/0x14e0 fs/open.c:940
                          vfs_open+0x3b/0x340 fs/open.c:1081
                          do_open fs/namei.c:4671 [inline]
                          path_openat+0x2e08/0x3860 fs/namei.c:4830
                          do_file_open+0x23e/0x4a0 fs/namei.c:4859
                          do_sys_openat2+0x113/0x200 fs/open.c:1366
                          do_sys_open fs/open.c:1372 [inline]
                          __do_sys_open fs/open.c:1380 [inline]
                          __se_sys_open fs/open.c:1376 [inline]
                          __x64_sys_open+0x11e/0x150 fs/open.c:1376
                          do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                          do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
                          entry_SYSCALL_64_after_hwframe+0x77/0x7f
  }
  ... key      at: [<ffffffff9a2e9200>] fasync_insert_entry.__key+0x0/0x20
  ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline]
   _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236
   kill_fasync_rcu fs/fcntl.c:1135 [inline]
   kill_fasync+0x199/0x4d0 fs/fcntl.c:1159
   tty_wakeup drivers/tty/tty_io.c:515 [inline]
   __start_tty+0x18c/0x220 drivers/tty/tty_io.c:777
   n_tty_ioctl_helper+0x128/0x4d0 drivers/tty/tty_ioctl.c:959
   tty_ioctl+0x9c5/0xde0 drivers/tty/tty_io.c:2801
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:597 [inline]
   __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> (&tty->flow.lock){....}-{3:3} {
   INITIAL USE at:
                   lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
                   _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
                   class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline]
                   start_tty+0x20/0x70 drivers/tty/tty_io.c:793
                   n_tty_set_termios+0xa7c/0x10c0 drivers/tty/n_tty.c:1848
                   tty_set_termios+0xdb3/0x1800 drivers/tty/tty_ioctl.c:348
                   set_termios+0x566/0x710 drivers/tty/tty_ioctl.c:516
                   tty_mode_ioctl+0x4a6/0x7d0 drivers/tty/tty_ioctl.c:-1
                   tty_ioctl+0x9c5/0xde0 drivers/tty/tty_io.c:2801
                   vfs_ioctl fs/ioctl.c:51 [inline]
                   __do_sys_ioctl fs/ioctl.c:597 [inline]
                   __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
                   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                   do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
                   entry_SYSCALL_64_after_hwframe+0x77/0x7f
 }
 ... key      at: [<ffffffff9a5c8680>] alloc_tty_struct.__key.35+0x0/0x20
 ... acquired at:
   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
   _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
   class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline]
   stop_tty+0x2f/0x150 drivers/tty/tty_io.c:765
   kbd_keycode drivers/tty/vt/keyboard.c:1497 [inline]
   kbd_event+0x2ec1/0x40d0 drivers/tty/vt/keyboard.c:1515
   input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
   input_pass_values+0x288/0x890 drivers/input/input.c:128
   input_event_dispose+0x330/0x6b0 drivers/input/input.c:342
   input_inject_event+0x1dd/0x340 drivers/input/input.c:424
   evdev_write+0x325/0x4c0 drivers/input/evdev.c:528
   vfs_write+0x29a/0xb90 fs/read_write.c:686
   ksys_write+0x150/0x270 fs/read_write.c:740
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f


stack backtrace:
CPU: 0 UID: 0 PID: 2262 Comm: syz.3.10721 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_bad_irq_dependency kernel/locking/lockdep.c:2616 [inline]
 check_irq_usage kernel/locking/lockdep.c:2857 [inline]
 check_prev_add kernel/locking/lockdep.c:3169 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x2a94/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
 _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
 class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline]
 stop_tty+0x2f/0x150 drivers/tty/tty_io.c:765
 kbd_keycode drivers/tty/vt/keyboard.c:1497 [inline]
 kbd_event+0x2ec1/0x40d0 drivers/tty/vt/keyboard.c:1515
 input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
 input_pass_values+0x288/0x890 drivers/input/input.c:128
 input_event_dispose+0x330/0x6b0 drivers/input/input.c:342
 input_inject_event+0x1dd/0x340 drivers/input/input.c:424
 evdev_write+0x325/0x4c0 drivers/input/evdev.c:528
 vfs_write+0x29a/0xb90 fs/read_write.c:686
 ksys_write+0x150/0x270 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6805d9c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6806d29028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6806015fa0 RCX: 00007f6805d9c799
RDX: 0000000000002250 RSI: 0000200000000040 RDI: 0000000000000004
RBP: 00007f6805e32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6806016038 R14: 00007f6806015fa0 R15: 00007f680613fa48
 </TASK>