syzbot

=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
syzkaller #0 Tainted: G             L     
-----------------------------------------------------
syz.6.9762/7416 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff88807ad0b468 (&tty->flow.lock){....}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline]
ffff88807ad0b468 (&tty->flow.lock){....}-{3:3}, at: stop_tty+0x2f/0x150 drivers/tty/tty_io.c:765

and this task is already holding:
ffffffff8eddff98 (kbd_event_lock){..-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffffff8eddff98 (kbd_event_lock){..-.}-{3:3}, at: class_spinlock_constructor include/linux/spinlock.h:565 [inline]
ffffffff8eddff98 (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+0x106/0x330 kernel/locking/lockdep.c:5868
  __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
  _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
  spin_lock include/linux/spinlock.h:351 [inline]
  class_spinlock_constructor include/linux/spinlock.h:565 [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_input_array_field+0x41c/0x5f0 drivers/hid/hid-core.c:1677
  hid_process_report drivers/hid/hid-core.c:1719 [inline]
  hid_report_raw_event+0xdd7/0x1720 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:1661
  dummy_timer+0xbbd/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1995
  __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
  __hrtimer_run_queues+0x527/0xc30 kernel/time/hrtimer.c:1841
  hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1858
  handle_softirqs+0x22a/0x7c0 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
  __sanitizer_cov_trace_const_cmp2+0x8/0x90 kernel/kcov.c:308
  d_flags_for_inode fs/dcache.c:1962 [inline]
  __d_instantiate+0xd9/0x6e0 fs/dcache.c:1973
  d_instantiate+0x80/0xc0 fs/dcache.c:2012
  alloc_path_pseudo fs/file_table.c:367 [inline]
  alloc_file_pseudo+0x107/0x240 fs/file_table.c:379
  __anon_inode_getfile fs/anon_inodes.c:166 [inline]
  anon_inode_getfile+0xc5/0x1a0 fs/anon_inodes.c:204
  do_epoll_create+0x286/0x3b0 fs/eventpoll.c:2186
  __do_sys_epoll_create1 fs/eventpoll.c:2199 [inline]
  __se_sys_epoll_create1 fs/eventpoll.c:2197 [inline]
  __x64_sys_epoll_create1+0x37/0x40 fs/eventpoll.c:2197
  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
  do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
  entry_SYSCALL_64_after_hwframe+0x77/0x7f

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

... which became SOFTIRQ-irq-unsafe at:
...
  lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
  __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
  _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
  __do_wait+0xde/0x740 kernel/exit.c:1672
  do_wait+0x1e7/0x4f0 kernel/exit.c:1716
  kernel_wait+0xd6/0x1c0 kernel/exit.c:1892
  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:3257 [inline]
  process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
  worker_thread+0xda6/0x1360 kernel/workqueue.c:3421
  kthread+0x726/0x8b0 kernel/kthread.c:463
  ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

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.6.9762/7416:
 #0: ffff88802a06f118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_write+0x1ae/0x4c0 drivers/input/evdev.c:511
 #1: ffff888029dd7230 (&dev->event_lock#2){..-.}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline]
 #1: ffff888029dd7230 (&dev->event_lock#2){..-.}-{3:3}, at: input_inject_event+0xa5/0x340 drivers/input/input.c:419
 #2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 #2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: input_inject_event+0xb6/0x340 drivers/input/input.c:420
 #3: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #3: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #3: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 #3: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: input_pass_values+0x8d/0x890 drivers/input/input.c:119
 #4: ffffffff8eddff98 (kbd_event_lock){..-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #4: ffffffff8eddff98 (kbd_event_lock){..-.}-{3:3}, at: class_spinlock_constructor include/linux/spinlock.h:565 [inline]
 #4: ffffffff8eddff98 (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+0x106/0x330 kernel/locking/lockdep.c:5868
                    __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
                    _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
                    spin_lock include/linux/spinlock.h:351 [inline]
                    class_spinlock_constructor include/linux/spinlock.h:565 [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_input_array_field+0x41c/0x5f0 drivers/hid/hid-core.c:1677
                    hid_process_report drivers/hid/hid-core.c:1719 [inline]
                    hid_report_raw_event+0xdd7/0x1720 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:1661
                    dummy_timer+0xbbd/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1995
                    __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
                    __hrtimer_run_queues+0x527/0xc30 kernel/time/hrtimer.c:1841
                    hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1858
                    handle_softirqs+0x22a/0x7c0 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
                    __sanitizer_cov_trace_const_cmp2+0x8/0x90 kernel/kcov.c:308
                    d_flags_for_inode fs/dcache.c:1962 [inline]
                    __d_instantiate+0xd9/0x6e0 fs/dcache.c:1973
                    d_instantiate+0x80/0xc0 fs/dcache.c:2012
                    alloc_path_pseudo fs/file_table.c:367 [inline]
                    alloc_file_pseudo+0x107/0x240 fs/file_table.c:379
                    __anon_inode_getfile fs/anon_inodes.c:166 [inline]
                    anon_inode_getfile+0xc5/0x1a0 fs/anon_inodes.c:204
                    do_epoll_create+0x286/0x3b0 fs/eventpoll.c:2186
                    __do_sys_epoll_create1 fs/eventpoll.c:2199 [inline]
                    __se_sys_epoll_create1 fs/eventpoll.c:2197 [inline]
                    __x64_sys_epoll_create1+0x37/0x40 fs/eventpoll.c:2197
                    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                    do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
                    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   INITIAL USE at:
                   lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
                   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
                   _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
                   class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline]
                   vt_reset_unicode+0x2b/0x1a0 drivers/tty/vt/keyboard.c:2117
                   reset_vc+0x68/0x1b0 drivers/tty/vt/vt_ioctl.c:966
                   vc_init+0x70/0x4a0 drivers/tty/vt/vt.c:3728
                   con_init+0x377/0x6a0 drivers/tty/vt/vt.c:3793
                   console_init+0xfc/0x3e0 kernel/printk/printk.c:4369
                   start_kernel+0x226/0x3d0 init/main.c:1143
                   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: [<ffffffff8eddff98>] 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+0x106/0x330 kernel/locking/lockdep.c:5868
                          __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
                          _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
                          __do_wait+0xde/0x740 kernel/exit.c:1672
                          do_wait+0x1e7/0x4f0 kernel/exit.c:1716
                          kernel_wait+0xd6/0x1c0 kernel/exit.c:1892
                          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:3257 [inline]
                          process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
                          worker_thread+0xda6/0x1360 kernel/workqueue.c:3421
                          kthread+0x726/0x8b0 kernel/kthread.c:463
                          ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
                          ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
      SOFTIRQ-ON-R at:
                          lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
                          __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
                          _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
                          __do_wait+0xde/0x740 kernel/exit.c:1672
                          do_wait+0x1e7/0x4f0 kernel/exit.c:1716
                          kernel_wait+0xd6/0x1c0 kernel/exit.c:1892
                          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:3257 [inline]
                          process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
                          worker_thread+0xda6/0x1360 kernel/workqueue.c:3421
                          kthread+0x726/0x8b0 kernel/kthread.c:463
                          ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
                          ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
      INITIAL USE at:
                         lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
                         __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
                         _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326
                         copy_process+0x2199/0x3980 kernel/fork.c:2367
                         kernel_clone+0x248/0x870 kernel/fork.c:2651
                         user_mode_thread+0x110/0x180 kernel/fork.c:2727
                         rest_init+0x23/0x300 init/main.c:722
                         start_kernel+0x380/0x3d0 init/main.c:1206
                         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+0x106/0x330 kernel/locking/lockdep.c:5868
                              __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
                              _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
                              __do_wait+0xde/0x740 kernel/exit.c:1672
                              do_wait+0x1e7/0x4f0 kernel/exit.c:1716
                              kernel_wait+0xd6/0x1c0 kernel/exit.c:1892
                              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:3257 [inline]
                              process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
                              worker_thread+0xda6/0x1360 kernel/workqueue.c:3421
                              kthread+0x726/0x8b0 kernel/kthread.c:463
                              ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
                              ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
    }
    ... key      at: [<ffffffff8e20c058>] tasklist_lock+0x18/0x40
    ... acquired at:
   __raw_read_lock include/linux/rwlock_api_smp.h:150 [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:357 [inline]
   send_to_group fs/notify/fsnotify.c:431 [inline]
   fsnotify+0x168e/0x1ae0 fs/notify/fsnotify.c:648
   __fsnotify_parent+0x50d/0x620 fs/notify/fsnotify.c:294
   notify_change+0xc55/0xf40 fs/attr.c:551
   do_truncate+0x1c2/0x250 fs/open.c:68
   vfs_truncate+0x4b4/0x540 fs/open.c:118
   do_sys_truncate+0xf1/0x1c0 fs/open.c:141
   __do_sys_truncate fs/open.c:153 [inline]
   __se_sys_truncate fs/open.c:151 [inline]
   __x64_sys_truncate+0x5b/0x70 fs/open.c:151
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

  -> (&f_owner->lock){....}-{3:3} {
     INITIAL USE at:
                       lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
                       __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
                       _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326
                       __f_setown+0x67/0x370 fs/fcntl.c:136
                       fcntl_dirnotify+0x3f9/0x6a0 fs/notify/dnotify/dnotify.c:369
                       do_fcntl+0x77e/0x1a20 fs/fcntl.c:538
                       __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+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
                       entry_SYSCALL_64_after_hwframe+0x77/0x7f
     INITIAL READ USE at:
                            lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
                            __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [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:567
                            __break_lease+0x741/0x1b80 fs/locks.c:1647
                            break_deleg include/linux/filelock.h:497 [inline]
                            try_break_deleg include/linux/filelock.h:516 [inline]
                            __vfs_setxattr_locked+0x189/0x240 fs/xattr.c:291
                            vfs_setxattr+0x16a/0x2e0 fs/xattr.c:321
                            do_setxattr fs/xattr.c:636 [inline]
                            filename_setxattr+0x281/0x630 fs/xattr.c:665
                            path_setxattrat+0x3f3/0x430 fs/xattr.c:713
                            __do_sys_lsetxattr fs/xattr.c:754 [inline]
                            __se_sys_lsetxattr fs/xattr.c:750 [inline]
                            __x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750
                            do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                            do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
                            entry_SYSCALL_64_after_hwframe+0x77/0x7f
   }
   ... key      at: [<ffffffff9a054c60>] file_f_owner_allocate.__key+0x0/0x20
   ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [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:567
   __break_lease+0x741/0x1b80 fs/locks.c:1647
   break_deleg include/linux/filelock.h:497 [inline]
   try_break_deleg include/linux/filelock.h:516 [inline]
   __vfs_setxattr_locked+0x189/0x240 fs/xattr.c:291
   vfs_setxattr+0x16a/0x2e0 fs/xattr.c:321
   do_setxattr fs/xattr.c:636 [inline]
   filename_setxattr+0x281/0x630 fs/xattr.c:665
   path_setxattrat+0x3f3/0x430 fs/xattr.c:713
   __do_sys_lsetxattr fs/xattr.c:754 [inline]
   __se_sys_lsetxattr fs/xattr.c:750 [inline]
   __x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

 -> (&new->fa_lock){....}-{3:3} {
    INITIAL USE at:
                     lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
                     __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
                     _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326
                     fasync_remove_entry+0xf1/0x1c0 fs/fcntl.c:1012
                     pipe_fasync+0xa9/0x1e0 fs/pipe.c:756
                     __fput+0x8a5/0xa70 fs/file_table.c:465
                     task_work_run+0x1d9/0x270 kernel/task_work.c:233
                     resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
                     __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
                     exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:75
                     __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
                     syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
                     syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
                     syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
                     do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100
                     entry_SYSCALL_64_after_hwframe+0x77/0x7f
    INITIAL READ USE at:
                          lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
                          __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [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
                          pipe_release+0x19c/0x330 fs/pipe.c:739
                          __fput+0x44f/0xa70 fs/file_table.c:468
                          task_work_run+0x1d9/0x270 kernel/task_work.c:233
                          resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
                          __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
                          exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:75
                          __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
                          syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
                          syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
                          syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
                          do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100
                          entry_SYSCALL_64_after_hwframe+0x77/0x7f
  }
  ... key      at: [<ffffffff9a054c80>] fasync_insert_entry.__key+0x0/0x20
  ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [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
   start_tty+0x2b/0x70 drivers/tty/tty_io.c:794
   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+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> (&tty->flow.lock){....}-{3:3} {
   INITIAL USE at:
                   lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
                   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
                   _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
                   class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [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+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
                   entry_SYSCALL_64_after_hwframe+0x77/0x7f
 }
 ... key      at: [<ffffffff9a332fa0>] alloc_tty_struct.__key.35+0x0/0x20
 ... acquired at:
   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
   _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
   class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [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:684
   ksys_write+0x150/0x270 fs/read_write.c:738
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f


stack backtrace:
CPU: 0 UID: 0 PID: 7416 Comm: syz.6.9762 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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+0x106/0x330 kernel/locking/lockdep.c:5868
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
 class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [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:684
 ksys_write+0x150/0x270 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6d5fd9aeb9
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:00007f6d60cc4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6d60015fa0 RCX: 00007f6d5fd9aeb9
RDX: 0000000000002250 RSI: 0000200000000040 RDI: 0000000000000007
RBP: 00007f6d5fe08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6d60016038 R14: 00007f6d60015fa0 R15: 00007f6d6013fa48
 </TASK>