=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
6.16.0-syzkaller-11895-gcca7a0aae895-dirty #0 Not tainted
-----------------------------------------------------
syz.8.3280/14785 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff88803756c2b8 (&new->fa_lock){....}-{3:3}, at: kill_fasync+0x199/0x4d0

and this task is already holding:
ffff888118ecd028 (&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+0x120/0x360
  _raw_spin_lock_irqsave+0xa7/0xf0
  input_event+0x76/0xe0
  hidinput_report_event+0xa1/0x100
  hid_report_raw_event+0x148b/0x16d0
  hid_input_report+0x43e/0x520
  hid_irq_in+0x47e/0x6d0
  __usb_hcd_giveback_urb+0x41a/0x690
  dummy_timer+0x862/0x4550
  __hrtimer_run_queues+0x52c/0xc60
  hrtimer_run_softirq+0x187/0x2b0
  handle_softirqs+0x286/0x870
  __irq_exit_rcu+0xca/0x1f0
  irq_exit_rcu+0x9/0x30
  sysvec_apic_timer_interrupt+0xa6/0xc0
  asm_sysvec_apic_timer_interrupt+0x1a/0x20
  lock_acquire+0x175/0x360
  pfn_valid+0xd6/0x490
  page_table_check_clear+0x21/0x700
  unmap_page_range+0x3445/0x4370
  unmap_vmas+0x399/0x580
  exit_mmap+0x248/0xb50
  __mmput+0x118/0x430
  exit_mm+0x1da/0x2c0
  do_exit+0x648/0x2300
  do_group_exit+0x21c/0x2d0
  get_signal+0x1286/0x1340
  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

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

... which became SOFTIRQ-irq-unsafe at:
...
  lock_acquire+0x120/0x360
  _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.8.3280/14785:
 #0: ffff88801ea33118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_write+0x1a1/0x480
 #1: ffff888106056230 (&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: ffff888118ecd028 (&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+0x120/0x360
                      _raw_spin_lock_irqsave+0xa7/0xf0
                      input_event+0x76/0xe0
                      hidinput_report_event+0xa1/0x100
                      hid_report_raw_event+0x148b/0x16d0
                      hid_input_report+0x43e/0x520
                      hid_irq_in+0x47e/0x6d0
                      __usb_hcd_giveback_urb+0x41a/0x690
                      dummy_timer+0x862/0x4550
                      __hrtimer_run_queues+0x52c/0xc60
                      hrtimer_run_softirq+0x187/0x2b0
                      handle_softirqs+0x286/0x870
                      __irq_exit_rcu+0xca/0x1f0
                      irq_exit_rcu+0x9/0x30
                      sysvec_apic_timer_interrupt+0xa6/0xc0
                      asm_sysvec_apic_timer_interrupt+0x1a/0x20
                      lock_acquire+0x175/0x360
                      pfn_valid+0xd6/0x490
                      page_table_check_clear+0x21/0x700
                      unmap_page_range+0x3445/0x4370
                      unmap_vmas+0x399/0x580
                      exit_mmap+0x248/0xb50
                      __mmput+0x118/0x430
                      exit_mm+0x1da/0x2c0
                      do_exit+0x648/0x2300
                      do_group_exit+0x21c/0x2d0
                      get_signal+0x1286/0x1340
                      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
    INITIAL USE at:
                     lock_acquire+0x120/0x360
                     _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: [<ffffffff99e22060>] input_allocate_device.__key.5+0x0/0x20
-> (&client->buffer_lock){....}-{3:3} {
   INITIAL USE at:
                   lock_acquire+0x120/0x360
                   _raw_spin_lock+0x2e/0x40
                   evdev_pass_values+0xb9/0xbd0
                   evdev_events+0x1aa/0x340
                   input_pass_values+0x1c2/0x890
                   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
 }
 ... key      at: [<ffffffff99e22300>] evdev_open.__key.25+0x0/0x20
 ... acquired at:
   lock_acquire+0x120/0x360
   _raw_spin_lock+0x2e/0x40
   evdev_pass_values+0xb9/0xbd0
   evdev_events+0x1aa/0x340
   input_pass_values+0x1c2/0x890
   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+0x120/0x360
                        _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+0x120/0x360
                        _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+0x120/0x360
                       _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+0x120/0x360
                            _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+0x120/0x360
   _raw_read_lock+0x36/0x50
   send_sigurg+0x12b/0x420
   sk_send_sigurg+0x6c/0x2e0
   queue_oob+0x420/0x4f0
   unix_stream_sendmsg+0xc3f/0xdf0
   __sock_sendmsg+0x21c/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

 -> (&f_owner->lock){....}-{3:3} {
    INITIAL USE at:
                     lock_acquire+0x120/0x360
                     _raw_write_lock_irq+0xa2/0xf0
                     __f_setown+0x67/0x370
                     fcntl_dirnotify+0x3fa/0x6a0
                     do_fcntl+0x6d0/0x1910
                     __se_sys_fcntl+0xc8/0x150
                     do_syscall_64+0xfa/0x3b0
                     entry_SYSCALL_64_after_hwframe+0x77/0x7f
    INITIAL READ USE at:
                          lock_acquire+0x120/0x360
                          _raw_read_lock_irqsave+0xaf/0x100
                          send_sigio+0x38/0x370
                          dnotify_handle_event+0x169/0x440
                          fsnotify+0x1814/0x1a80
                          vfs_readv+0x703/0x850
                          __x64_sys_preadv+0x197/0x2a0
                          do_syscall_64+0xfa/0x3b0
                          entry_SYSCALL_64_after_hwframe+0x77/0x7f
  }
  ... key      at: [<ffffffff99b22f60>] file_f_owner_allocate.__key+0x0/0x20
  ... acquired at:
   lock_acquire+0x120/0x360
   _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+0x120/0x360
                   _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+0x120/0x360
                        _raw_read_lock_irqsave+0xaf/0x100
                        kill_fasync+0x199/0x4d0
                        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
 }
 ... key      at: [<ffffffff99b22f80>] fasync_insert_entry.__key+0x0/0x20
 ... acquired at:
   lock_acquire+0x120/0x360
   _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: 0 UID: 0 PID: 14785 Comm: syz.8.3280 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+0x120/0x360
 _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: 0033:0x7f57c4d8ebe9
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:00007f57c5ba8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f57c4fb5fa0 RCX: 00007f57c4d8ebe9
RDX: 0000000000001068 RSI: 0000200000000040 RDI: 0000000000000004
RBP: 00007f57c4e11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f57c4fb6038 R14: 00007f57c4fb5fa0 R15: 00007ffc3222d9f8
 </TASK>
