=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
6.16.0-syzkaller-11895-gcca7a0aae895-dirty #0 Not tainted
-----------------------------------------------------
syz.6.5547/19448 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff88810cb19360 (&new->fa_lock){....}-{3:3}, at: kill_fasync+0x199/0x4d0

and this task is already holding:
ffff888107755028 (&client->buffer_lock){....}-{3:3}, at: evdev_pass_values+0xb9/0xbd0
which would create a new lock dependency:
 (&client->buffer_lock){....}-{3:3} -> (&new->fa_lock){....}-{3:3}

but this new dependency connects a SOFTIRQ-irq-safe lock:
 (&dev->event_lock#2){..-.}-{3:3}

... which became SOFTIRQ-irq-safe at:
  lock_acquire+0x126/0x360
  _raw_spin_lock_irqsave+0xa7/0xf0
  input_inject_event+0xa5/0x340
  led_trigger_event+0x138/0x210
  kbd_bh+0x1c6/0x2e0
  tasklet_action_common+0x36c/0x580
  handle_softirqs+0x286/0x870
  run_ksoftirqd+0x9b/0x100
  smpboot_thread_fn+0x542/0xa60
  kthread+0x711/0x8a0
  ret_from_fork+0x3fc/0x770
  ret_from_fork_asm+0x1a/0x30

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

... which became SOFTIRQ-irq-unsafe at:
...
  lock_acquire+0x126/0x360
  _raw_read_lock+0x36/0x50
  __do_wait+0xde/0x740
  do_wait+0x1f8/0x520
  kernel_wait+0xab/0x170
  call_usermodehelper_exec_work+0xbe/0x230
  process_scheduled_works+0xae1/0x17b0
  worker_thread+0x8a0/0xda0
  kthread+0x711/0x8a0
  ret_from_fork+0x3fc/0x770
  ret_from_fork_asm+0x1a/0x30

other info that might help us debug this:

Chain exists of:
  &dev->event_lock#2 --> &client->buffer_lock --> tasklist_lock

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(tasklist_lock);
                               local_irq_disable();
                               lock(&dev->event_lock#2);
                               lock(&client->buffer_lock);
  <Interrupt>
    lock(&dev->event_lock#2);

 *** DEADLOCK ***

7 locks held by syz.6.5547/19448:
 #0: ffff888108f11118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_write+0x1a1/0x480
 #1: ffff88801ee0e230 (&dev->event_lock#2){..-.}-{3:3}, at: input_inject_event+0xa5/0x340
 #2: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: input_inject_event+0xb6/0x340
 #3: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: input_pass_values+0x8d/0x890
 #4: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: evdev_events+0x79/0x340
 #5: ffff888107755028 (&client->buffer_lock){....}-{3:3}, at: evdev_pass_values+0xb9/0xbd0
 #6: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: kill_fasync+0x53/0x4d0

the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
 -> (&dev->event_lock#2){..-.}-{3:3} {
    IN-SOFTIRQ-W at:
                      lock_acquire+0x126/0x360
                      _raw_spin_lock_irqsave+0xa7/0xf0
                      input_inject_event+0xa5/0x340
                      led_trigger_event+0x138/0x210
                      kbd_bh+0x1c6/0x2e0
                      tasklet_action_common+0x36c/0x580
                      handle_softirqs+0x286/0x870
                      run_ksoftirqd+0x9b/0x100
                      smpboot_thread_fn+0x542/0xa60
                      kthread+0x711/0x8a0
                      ret_from_fork+0x3fc/0x770
                      ret_from_fork_asm+0x1a/0x30
    INITIAL USE at:
                     lock_acquire+0x126/0x360
                     _raw_spin_lock_irqsave+0xa7/0xf0
                     input_inject_event+0xa5/0x340
                     kbd_led_trigger_activate+0xbc/0x100
                     led_trigger_set+0x52d/0x950
                     led_trigger_set_default+0x260/0x2a0
                     led_classdev_register_ext+0x73d/0x930
                     input_leds_connect+0x517/0x790
                     input_register_device+0xd0e/0x1140
                     atkbd_connect+0x72e/0xa00
                     serio_driver_probe+0x82/0xd0
                     really_probe+0x26d/0x9e0
                     __driver_probe_device+0x18c/0x2f0
                     driver_probe_device+0x4f/0x430
                     __driver_attach+0x452/0x700
                     bus_for_each_dev+0x233/0x2b0
                     serio_handle_event+0x1f9/0x8d0
                     process_scheduled_works+0xae1/0x17b0
                     worker_thread+0x8a0/0xda0
                     kthread+0x711/0x8a0
                     ret_from_fork+0x3fc/0x770
                     ret_from_fork_asm+0x1a/0x30
  }
  ... key      at: [<ffffffff99e230a0>] input_allocate_device.__key.5+0x0/0x20
-> (&client->buffer_lock){....}-{3:3} {
   INITIAL USE at:
                   lock_acquire+0x126/0x360
                   _raw_spin_lock_irq+0xa2/0xf0
                   evdev_read+0x370/0xca0
                   vfs_readv+0x5aa/0x850
                   do_readv+0x14d/0x2d0
                   do_syscall_64+0xfa/0x3b0
                   entry_SYSCALL_64_after_hwframe+0x77/0x7f
 }
 ... key      at: [<ffffffff99e23340>] evdev_open.__key.25+0x0/0x20
 ... acquired at:
   lock_acquire+0x126/0x360
   _raw_spin_lock+0x2e/0x40
   evdev_pass_values+0xb9/0xbd0
   evdev_events+0x1e6/0x340
   input_pass_values+0x288/0x890
   input_event_dispose+0x330/0x6b0
   input_inject_event+0x1dd/0x340
   evdev_write+0x2fc/0x480
   vfs_write+0x27e/0xa90
   ksys_write+0x145/0x250
   do_syscall_64+0xfa/0x3b0
   entry_SYSCALL_64_after_hwframe+0x77/0x7f


the dependencies between the lock to be acquired
 and SOFTIRQ-irq-unsafe lock:
  -> (tasklist_lock){.+.+}-{3:3} {
     HARDIRQ-ON-R at:
                        lock_acquire+0x126/0x360
                        _raw_read_lock+0x36/0x50
                        __do_wait+0xde/0x740
                        do_wait+0x1f8/0x520
                        kernel_wait+0xab/0x170
                        call_usermodehelper_exec_work+0xbe/0x230
                        process_scheduled_works+0xae1/0x17b0
                        worker_thread+0x8a0/0xda0
                        kthread+0x711/0x8a0
                        ret_from_fork+0x3fc/0x770
                        ret_from_fork_asm+0x1a/0x30
     SOFTIRQ-ON-R at:
                        lock_acquire+0x126/0x360
                        _raw_read_lock+0x36/0x50
                        __do_wait+0xde/0x740
                        do_wait+0x1f8/0x520
                        kernel_wait+0xab/0x170
                        call_usermodehelper_exec_work+0xbe/0x230
                        process_scheduled_works+0xae1/0x17b0
                        worker_thread+0x8a0/0xda0
                        kthread+0x711/0x8a0
                        ret_from_fork+0x3fc/0x770
                        ret_from_fork_asm+0x1a/0x30
     INITIAL USE at:
                       lock_acquire+0x126/0x360
                       _raw_write_lock_irq+0xa2/0xf0
                       copy_process+0x224f/0x3c00
                       kernel_clone+0x21e/0x840
                       user_mode_thread+0xdd/0x140
                       rest_init+0x23/0x300
                       start_kernel+0x3a9/0x410
                       x86_64_start_reservations+0x24/0x30
                       x86_64_start_kernel+0x143/0x1c0
                       common_startup_64+0x13e/0x147
     INITIAL READ USE at:
                            lock_acquire+0x126/0x360
                            _raw_read_lock+0x36/0x50
                            __do_wait+0xde/0x740
                            do_wait+0x1f8/0x520
                            kernel_wait+0xab/0x170
                            call_usermodehelper_exec_work+0xbe/0x230
                            process_scheduled_works+0xae1/0x17b0
                            worker_thread+0x8a0/0xda0
                            kthread+0x711/0x8a0
                            ret_from_fork+0x3fc/0x770
                            ret_from_fork_asm+0x1a/0x30
   }
   ... key      at: [<ffffffff8de0c058>] tasklist_lock+0x18/0x40
   ... acquired at:
   lock_acquire+0x126/0x360
   _raw_read_lock+0x36/0x50
   send_sigio+0x101/0x370
   dnotify_handle_event+0x169/0x440
   fsnotify+0x1814/0x1a80
   fsnotify_move+0x1d7/0x5b0
   vfs_rename+0x90b/0xf00
   do_renameat2+0x6ce/0xa80
   __x64_sys_renameat2+0xce/0xe0
   do_syscall_64+0xfa/0x3b0
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

 -> (&f_owner->lock){....}-{3:3} {
    INITIAL USE at:
                     lock_acquire+0x126/0x360
                     _raw_write_lock_irq+0xa2/0xf0
                     __f_setown+0x67/0x370
                     generic_setlease+0xd60/0x1240
                     fcntl_setlease+0x3a2/0x4c0
                     do_fcntl+0x6a9/0x1910
                     __se_sys_fcntl+0xc8/0x150
                     do_syscall_64+0xfa/0x3b0
                     entry_SYSCALL_64_after_hwframe+0x77/0x7f
    INITIAL READ USE at:
                          lock_acquire+0x126/0x360
                          _raw_read_lock_irqsave+0xaf/0x100
                          send_sigio+0x38/0x370
                          dnotify_handle_event+0x169/0x440
                          fsnotify+0x1671/0x1a80
                          __fsnotify_parent+0x3fe/0x540
                          notify_change+0xb70/0xe40
                          vfs_utimes+0x3fb/0x570
                          do_utimes+0x182/0x2a0
                          __x64_sys_utimensat+0x14f/0x230
                          do_syscall_64+0xfa/0x3b0
                          entry_SYSCALL_64_after_hwframe+0x77/0x7f
  }
  ... key      at: [<ffffffff99b23f80>] file_f_owner_allocate.__key+0x0/0x20
  ... acquired at:
   lock_acquire+0x126/0x360
   _raw_read_lock_irqsave+0xaf/0x100
   send_sigio+0x38/0x370
   kill_fasync+0x24d/0x4d0
   sock_wake_async+0x137/0x160
   sk_wake_async+0x184/0x280
   unix_release_sock+0x768/0xd30
   unix_release+0x92/0xd0
   sock_close+0xc3/0x240
   __fput+0x44c/0xa70
   task_work_run+0x1d4/0x260
   get_signal+0x11ed/0x1340
   arch_do_signal_or_restart+0x9a/0x750
   exit_to_user_mode_loop+0x75/0x110
   do_syscall_64+0x2bd/0x3b0
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> (&new->fa_lock){....}-{3:3} {
   INITIAL USE at:
                   lock_acquire+0x126/0x360
                   _raw_write_lock_irq+0xa2/0xf0
                   fasync_remove_entry+0xf1/0x1c0
                   sock_fasync+0x85/0xf0
                   __fput+0x8a2/0xa70
                   task_work_run+0x1d4/0x260
                   exit_to_user_mode_loop+0xec/0x110
                   do_syscall_64+0x2bd/0x3b0
                   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   INITIAL READ USE at:
                        lock_acquire+0x126/0x360
                        _raw_read_lock_irqsave+0xaf/0x100
                        kill_fasync+0x199/0x4d0
                        sock_wake_async+0x137/0x160
                        sk_wake_async+0x189/0x280
                        tcp_rcv_state_process+0x1f9b/0x4140
                        tcp_v4_do_rcv+0x3f2/0xce0
                        __release_sock+0x21c/0x350
                        release_sock+0x5f/0x1f0
                        tcp_sendmsg+0x39/0x50
                        __sock_sendmsg+0x19c/0x270
                        ____sys_sendmsg+0x505/0x830
                        ___sys_sendmsg+0x21f/0x2a0
                        __x64_sys_sendmsg+0x19b/0x260
                        do_syscall_64+0xfa/0x3b0
                        entry_SYSCALL_64_after_hwframe+0x77/0x7f
 }
 ... key      at: [<ffffffff99b23fa0>] fasync_insert_entry.__key+0x0/0x20
 ... acquired at:
   lock_acquire+0x126/0x360
   _raw_read_lock_irqsave+0xaf/0x100
   kill_fasync+0x199/0x4d0
   evdev_pass_values+0x627/0xbd0
   evdev_events+0x1e6/0x340
   input_pass_values+0x288/0x890
   input_event_dispose+0x330/0x6b0
   input_inject_event+0x1dd/0x340
   evdev_write+0x2fc/0x480
   vfs_write+0x27e/0xa90
   ksys_write+0x145/0x250
   do_syscall_64+0xfa/0x3b0
   entry_SYSCALL_64_after_hwframe+0x77/0x7f


stack backtrace:
CPU: 1 UID: 0 PID: 19448 Comm: syz.6.5547 Not tainted 6.16.0-syzkaller-11895-gcca7a0aae895-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 validate_chain+0x1f05/0x2140
 __lock_acquire+0xab9/0xd20
 lock_acquire+0x126/0x360
 _raw_read_lock_irqsave+0xaf/0x100
 kill_fasync+0x199/0x4d0
 evdev_pass_values+0x627/0xbd0
 evdev_events+0x1e6/0x340
 input_pass_values+0x288/0x890
 input_event_dispose+0x330/0x6b0
 input_inject_event+0x1dd/0x340
 evdev_write+0x2fc/0x480
 vfs_write+0x27e/0xa90
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f41de58ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f41df390038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f41de7b5fa0 RCX: 00007f41de58ebe9
RDX: 0000000000001068 RSI: 0000200000000040 RDI: 0000000000000004
RBP: 00007f41de611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f41de7b6038 R14: 00007f41de7b5fa0 R15: 00007ffe45d576c8
 </TASK>
