syzbot

=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
syzkaller #0 Tainted: G             L     
-----------------------------------------------------
syz.3.9739/6822 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffffffff8e40c058 (tasklist_lock){.+.+}-{3:3}, at: send_sigio+0x101/0x370 fs/fcntl.c:932

and this task is already holding:
ffff888035445ea0 (&f_owner->lock){....}-{3:3}, at: send_sigio+0x38/0x370 fs/fcntl.c:918
which would create a new lock dependency:
 (&f_owner->lock){....}-{3:3} -> (tasklist_lock){.+.+}-{3:3}

but this new dependency connects a SOFTIRQ-irq-safe lock:
 (&client->buffer_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:158 [inline]
  _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
  spin_lock include/linux/spinlock.h:341 [inline]
  evdev_pass_values+0xb9/0xbd0 drivers/input/evdev.c:261
  evdev_events+0x1e6/0x340 drivers/input/evdev.c:306
  input_pass_values+0x288/0x890 drivers/input/input.c:128
  input_event_dispose drivers/input/input.c:342 [inline]
  input_handle_event drivers/input/input.c:370 [inline]
  input_repeat_key+0x41a/0x680 drivers/input/input.c:2228
  call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748
  expire_timers kernel/time/timer.c:1799 [inline]
  __run_timers kernel/time/timer.c:2373 [inline]
  __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
  run_timer_base kernel/time/timer.c:2394 [inline]
  run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
  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
  lock_release+0x2d7/0x3a0 kernel/locking/lockdep.c:5893
  rcu_lock_release include/linux/rcupdate.h:322 [inline]
  rcu_read_unlock include/linux/rcupdate.h:881 [inline]
  class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
  unwind_next_frame+0x1aaa/0x23c0 arch/x86/kernel/unwind_orc.c:695
  arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
  stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
  save_stack+0x122/0x230 mm/page_owner.c:165
  __set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
  set_page_owner include/linux/page_owner.h:32 [inline]
  post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884
  prep_new_page mm/page_alloc.c:1892 [inline]
  get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3950
  __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5245
  alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
  folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2505
  shmem_alloc_folio mm/shmem.c:1919 [inline]
  shmem_alloc_and_add_folio+0x445/0xf80 mm/shmem.c:1961
  shmem_get_folio_gfp+0x5a9/0x1670 mm/shmem.c:2585
  shmem_fault+0x179/0x390 mm/shmem.c:2786
  __do_fault+0x138/0x390 mm/memory.c:5323
  do_read_fault mm/memory.c:5758 [inline]
  do_fault mm/memory.c:5892 [inline]
  do_pte_missing+0x21a2/0x37a0 mm/memory.c:4404
  handle_pte_fault mm/memory.c:6276 [inline]
  __handle_mm_fault mm/memory.c:6414 [inline]
  handle_mm_fault+0x1b8c/0x32a0 mm/memory.c:6583
  faultin_page mm/gup.c:1126 [inline]
  __get_user_pages+0x165b/0x29d0 mm/gup.c:1428
  populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860
  __mm_populate+0x25f/0x390 mm/gup.c:1963
  mm_populate include/linux/mm.h:3682 [inline]
  vm_mmap_pgoff+0x3aa/0x4f0 mm/util.c:586
  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

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:161 [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:3275 [inline]
  process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358
  worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
  kthread+0x388/0x470 kernel/kthread.c:467
  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:
  &client->buffer_lock --> &f_owner->lock --> tasklist_lock

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(tasklist_lock);
                               local_irq_disable();
                               lock(&client->buffer_lock);
                               lock(&f_owner->lock);
  <Interrupt>
    lock(&client->buffer_lock);

 *** DEADLOCK ***

5 locks held by syz.3.9739/6822:
 #0: ffff888035e3a420 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
 #1: ffff888069bf8fb8 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock_killable include/linux/fs.h:1033 [inline]
 #1: ffff888069bf8fb8 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: do_truncate+0x18f/0x250 fs/open.c:63
 #2: ffffffff9a293378 (&fsnotify_mark_srcu){.+.?}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
 #2: ffffffff9a293378 (&fsnotify_mark_srcu){.+.?}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
 #2: ffffffff9a293378 (&fsnotify_mark_srcu){.+.?}-{0:0}, at: fsnotify+0x74c/0x1ae0 fs/notify/fsnotify.c:619
 #3: ffff888048102e48 (&mark->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline]
 #3: ffff888048102e48 (&mark->lock){+.+.}-{3:3}, at: dnotify_handle_event+0x62/0x440 fs/notify/dnotify/dnotify.c:105
 #4: ffff888035445ea0 (&f_owner->lock){....}-{3:3}, at: send_sigio+0x38/0x370 fs/fcntl.c:918

the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
  -> (&client->buffer_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:158 [inline]
                        _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
                        spin_lock include/linux/spinlock.h:341 [inline]
                        evdev_pass_values+0xb9/0xbd0 drivers/input/evdev.c:261
                        evdev_events+0x1e6/0x340 drivers/input/evdev.c:306
                        input_pass_values+0x288/0x890 drivers/input/input.c:128
                        input_event_dispose drivers/input/input.c:342 [inline]
                        input_handle_event drivers/input/input.c:370 [inline]
                        input_repeat_key+0x41a/0x680 drivers/input/input.c:2228
                        call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748
                        expire_timers kernel/time/timer.c:1799 [inline]
                        __run_timers kernel/time/timer.c:2373 [inline]
                        __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
                        run_timer_base kernel/time/timer.c:2394 [inline]
                        run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
                        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
                        lock_release+0x2d7/0x3a0 kernel/locking/lockdep.c:5893
                        rcu_lock_release include/linux/rcupdate.h:322 [inline]
                        rcu_read_unlock include/linux/rcupdate.h:881 [inline]
                        class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
                        unwind_next_frame+0x1aaa/0x23c0 arch/x86/kernel/unwind_orc.c:695
                        arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
                        stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
                        save_stack+0x122/0x230 mm/page_owner.c:165
                        __set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
                        set_page_owner include/linux/page_owner.h:32 [inline]
                        post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884
                        prep_new_page mm/page_alloc.c:1892 [inline]
                        get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3950
                        __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5245
                        alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
                        folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2505
                        shmem_alloc_folio mm/shmem.c:1919 [inline]
                        shmem_alloc_and_add_folio+0x445/0xf80 mm/shmem.c:1961
                        shmem_get_folio_gfp+0x5a9/0x1670 mm/shmem.c:2585
                        shmem_fault+0x179/0x390 mm/shmem.c:2786
                        __do_fault+0x138/0x390 mm/memory.c:5323
                        do_read_fault mm/memory.c:5758 [inline]
                        do_fault mm/memory.c:5892 [inline]
                        do_pte_missing+0x21a2/0x37a0 mm/memory.c:4404
                        handle_pte_fault mm/memory.c:6276 [inline]
                        __handle_mm_fault mm/memory.c:6414 [inline]
                        handle_mm_fault+0x1b8c/0x32a0 mm/memory.c:6583
                        faultin_page mm/gup.c:1126 [inline]
                        __get_user_pages+0x165b/0x29d0 mm/gup.c:1428
                        populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860
                        __mm_populate+0x25f/0x390 mm/gup.c:1963
                        mm_populate include/linux/mm.h:3682 [inline]
                        vm_mmap_pgoff+0x3aa/0x4f0 mm/util.c:586
                        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 USE at:
                       lock_acquire+0x106/0x330 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]
                       evdev_pass_values+0xb9/0xbd0 drivers/input/evdev.c:261
                       evdev_events+0x1e6/0x340 drivers/input/evdev.c:306
                       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
   }
   ... key      at: [<ffffffff9a5ae6a0>] evdev_open.__key.27+0x0/0x20
 -> (&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:211 [inline]
                     _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326
                     fasync_remove_entry+0xf1/0x1c0 fs/fcntl.c:1012
                     lease_modify+0x4f7/0x6c0 fs/locks.c:1514
                     locks_remove_lease fs/locks.c:2746 [inline]
                     locks_remove_file+0x5f0/0xf70 fs/locks.c:2771
                     __fput+0x3ae/0xa70 fs/file_table.c:461
                     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:67 [inline]
                     exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
                     __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 include/linux/entry-common.h:325 [inline]
                     do_syscall_64+0x32d/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: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/0x1d90 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_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
  }
  ... key      at: [<ffffffff9a290400>] 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
   __pass_event drivers/input/evdev.c:240 [inline]
   evdev_pass_values+0x627/0xbd0 drivers/input/evdev.c:278
   evdev_events+0x1e6/0x340 drivers/input/evdev.c:306
   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

-> (&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: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/0xf90 fs/locks.c:1984
                   do_fcntl_add_lease+0x35e/0x470 fs/locks.c:2086
                   fcntl_setdeleg+0x14c/0x1e0 fs/locks.c:2132
                   do_fcntl+0xe6d/0x1a20 fs/fcntl.c:564
                   __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+0x106/0x330 kernel/locking/lockdep.c:5868
                        __raw_read_lock_irq include/linux/rwlock_api_smp.h:182 [inline]
                        _raw_read_lock_irq+0x45/0x60 kernel/locking/spinlock.c:244
                        f_getown_ex fs/fcntl.c:270 [inline]
                        do_fcntl+0x30f/0x1a20 fs/fcntl.c:517
                        __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
 }
 ... key      at: [<ffffffff9a2903e0>] 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/0x1d90 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_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


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:161 [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:3275 [inline]
                    process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358
                    worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
                    kthread+0x388/0x470 kernel/kthread.c:467
                    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+0x106/0x330 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: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:3275 [inline]
                    process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358
                    worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
                    kthread+0x388/0x470 kernel/kthread.c:467
                    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+0x106/0x330 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+0x248/0x870 kernel/fork.c:2654
                   user_mode_thread+0x110/0x180 kernel/fork.c:2730
                   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:161 [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:3275 [inline]
                        process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358
                        worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
                        kthread+0x388/0x470 kernel/kthread.c:467
                        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: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+0xf3/0x1c0 fs/open.c:142
   __do_sys_truncate fs/open.c:154 [inline]
   __se_sys_truncate fs/open.c:152 [inline]
   __x64_sys_truncate+0x5b/0x70 fs/open.c:152
   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: 1 UID: 0 PID: 6822 Comm: syz.3.9739 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_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: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+0xf3/0x1c0 fs/open.c:142
 __do_sys_truncate fs/open.c:154 [inline]
 __se_sys_truncate fs/open.c:152 [inline]
 __x64_sys_truncate+0x5b/0x70 fs/open.c:152
 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: 0033:0x7f5c0579bf79
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:00007f5c066b4028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007f5c05a15fa0 RCX: 00007f5c0579bf79
RDX: 0000000000000000 RSI: 000000000008fff5 RDI: 0000200000000180
RBP: 00007f5c058327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5c05a16038 R14: 00007f5c05a15fa0 R15: 00007ffdbe293bf8
 </TASK>