=====================================================
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
syzkaller #0 Not tainted
-----------------------------------------------------
syz.4.21/6832 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff800097391d90 (&p->sequence){+.-.}-{0:0}, at: __fprop_add_percpu_max+0x130/0x1f4 lib/flex_proportions.c:186

and this task is already holding:
ffff0000e3648240 (&xa->xa_lock#10){-...}-{3:3}, at: __folio_end_writeback+0x10c/0x75c mm/page-writeback.c:2996
which would create a new lock dependency:
 (&xa->xa_lock#10){-...}-{3:3} -> (&p->sequence){+.-.}-{0:0}

but this new dependency connects a HARDIRQ-irq-safe lock:
 (&xa->xa_lock#10){-...}-{3:3}

... which became HARDIRQ-irq-safe at:
  lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
  __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
  _raw_spin_lock_irqsave+0x5c/0x7c kernel/locking/spinlock.c:162
  __folio_end_writeback+0x10c/0x75c mm/page-writeback.c:2996
  folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1668
  folio_end_writeback+0xd8/0x248 mm/filemap.c:1694
  end_buffer_async_write+0x20c/0x350 fs/buffer.c:419
  end_bio_bh_io_sync+0xb0/0x184 fs/buffer.c:2776
  bio_endio+0x858/0x894 block/bio.c:1672
  blk_complete_request block/blk-mq.c:899 [inline]
  blk_mq_end_request_batch+0x49c/0x105c block/blk-mq.c:1193
  nvme_complete_batch drivers/nvme/host/nvme.h:795 [inline]
  nvme_pci_complete_batch drivers/nvme/host/pci.c:1270 [inline]
  nvme_irq+0x1ec/0x240 drivers/nvme/host/pci.c:1372
  __handle_irq_event_percpu+0x224/0x8e4 kernel/irq/handle.c:203
  handle_irq_event_percpu kernel/irq/handle.c:240 [inline]
  handle_irq_event+0x9c/0x1d0 kernel/irq/handle.c:257
  handle_fasteoi_irq+0x328/0x8d8 kernel/irq/chip.c:764
  generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
  handle_irq_desc kernel/irq/irqdesc.c:669 [inline]
  generic_handle_domain_irq+0xe0/0x140 kernel/irq/irqdesc.c:725
  __gic_handle_irq drivers/irqchip/irq-gic-v3.c:874 [inline]
  __gic_handle_irq_from_irqson drivers/irqchip/irq-gic-v3.c:925 [inline]
  gic_handle_irq+0x6c/0x190 drivers/irqchip/irq-gic-v3.c:969
  call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891
  do_interrupt_handler+0xd4/0x138 arch/arm64/kernel/entry-common.c:157
  __el1_irq arch/arm64/kernel/entry-common.c:519 [inline]
  el1_interrupt+0x3c/0x60 arch/arm64/kernel/entry-common.c:532
  el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:537
  el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:592
  __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline]
  arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline]
  lock_release+0x270/0x39c kernel/locking/lockdep.c:5892
  __might_fault+0xf0/0x124 mm/memory.c:7081
  setup_sigframe arch/arm64/kernel/signal.c:1237 [inline]
  setup_rt_frame arch/arm64/kernel/signal.c:1511 [inline]
  handle_signal arch/arm64/kernel/signal.c:1559 [inline]
  arch_do_signal_or_restart+0xb28/0x4414 arch/arm64/kernel/signal.c:1634
  exit_to_user_mode_loop+0x7c/0x178 kernel/entry/common.c:40
  exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
  arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline]
  el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:747
  el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765
  el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

to a HARDIRQ-irq-unsafe lock:
 (&p->sequence){+.-.}-{0:0}

... which became HARDIRQ-irq-unsafe at:
...
  lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
  do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline]
  do_write_seqcount_begin include/linux/seqlock.h:503 [inline]
  fprop_new_period+0x3b8/0x718 lib/flex_proportions.c:74
  writeout_period+0x94/0x11c mm/page-writeback.c:615
  call_timer_fn+0x1b4/0x818 kernel/time/timer.c:1747
  expire_timers kernel/time/timer.c:1798 [inline]
  __run_timers kernel/time/timer.c:2372 [inline]
  __run_timer_base+0x51c/0x76c kernel/time/timer.c:2384
  run_timer_base kernel/time/timer.c:2393 [inline]
  run_timer_softirq+0x11c/0x194 kernel/time/timer.c:2404
  handle_softirqs+0x328/0xc88 kernel/softirq.c:622
  __do_softirq+0x14/0x20 kernel/softirq.c:656
  ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:68
  call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891
  do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:73
  invoke_softirq kernel/softirq.c:503 [inline]
  __irq_exit_rcu+0x1b0/0x478 kernel/softirq.c:723
  irq_exit_rcu+0x14/0x84 kernel/softirq.c:739
  __el1_irq arch/arm64/kernel/entry-common.c:520 [inline]
  el1_interrupt+0x40/0x60 arch/arm64/kernel/entry-common.c:532
  el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:537
  el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:592
  __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline]
  arch_local_irq_restore+0x8/0xc arch/arm64/include/asm/irqflags.h:195
  lock_is_held include/linux/lockdep.h:249 [inline]
  __might_resched+0x98/0x4c4 kernel/sched/core.c:8887
  __might_sleep+0x94/0x110 kernel/sched/core.c:8854
  try_to_freeze include/linux/freezer.h:54 [inline]
  get_signal+0xfc/0x12f8 kernel/signal.c:2820
  arch_do_signal_or_restart+0x1c0/0x4414 arch/arm64/kernel/signal.c:1619
  exit_to_user_mode_loop+0x7c/0x178 kernel/entry/common.c:40
  exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
  arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline]
  el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:747
  el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765
  el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

other info that might help us debug this:

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&p->sequence);
                               local_irq_disable();
                               lock(&xa->xa_lock#10);
                               lock(&p->sequence);
  <Interrupt>
    lock(&xa->xa_lock#10);

 *** DEADLOCK ***

2 locks held by syz.4.21/6832:
 #0: ffff0000e3648638 (&fi->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #0: ffff0000e3648638 (&fi->lock){+.+.}-{3:3}, at: fuse_writepages_send fs/fuse/file.c:2089 [inline]
 #0: ffff0000e3648638 (&fi->lock){+.+.}-{3:3}, at: fuse_iomap_writeback_range+0x3b8/0x152c fs/fuse/file.c:2150
 #1: ffff0000e3648240 (&xa->xa_lock#10){-...}-{3:3}, at: __folio_end_writeback+0x10c/0x75c mm/page-writeback.c:2996

the dependencies between HARDIRQ-irq-safe lock and the holding lock:
-> (&xa->xa_lock#10){-...}-{3:3} {
   IN-HARDIRQ-W at:
                    lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
                    __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
                    _raw_spin_lock_irqsave+0x5c/0x7c kernel/locking/spinlock.c:162
                    __folio_end_writeback+0x10c/0x75c mm/page-writeback.c:2996
                    folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1668
                    folio_end_writeback+0xd8/0x248 mm/filemap.c:1694
                    end_buffer_async_write+0x20c/0x350 fs/buffer.c:419
                    end_bio_bh_io_sync+0xb0/0x184 fs/buffer.c:2776
                    bio_endio+0x858/0x894 block/bio.c:1672
                    blk_complete_request block/blk-mq.c:899 [inline]
                    blk_mq_end_request_batch+0x49c/0x105c block/blk-mq.c:1193
                    nvme_complete_batch drivers/nvme/host/nvme.h:795 [inline]
                    nvme_pci_complete_batch drivers/nvme/host/pci.c:1270 [inline]
                    nvme_irq+0x1ec/0x240 drivers/nvme/host/pci.c:1372
                    __handle_irq_event_percpu+0x224/0x8e4 kernel/irq/handle.c:203
                    handle_irq_event_percpu kernel/irq/handle.c:240 [inline]
                    handle_irq_event+0x9c/0x1d0 kernel/irq/handle.c:257
                    handle_fasteoi_irq+0x328/0x8d8 kernel/irq/chip.c:764
                    generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
                    handle_irq_desc kernel/irq/irqdesc.c:669 [inline]
                    generic_handle_domain_irq+0xe0/0x140 kernel/irq/irqdesc.c:725
                    __gic_handle_irq drivers/irqchip/irq-gic-v3.c:874 [inline]
                    __gic_handle_irq_from_irqson drivers/irqchip/irq-gic-v3.c:925 [inline]
                    gic_handle_irq+0x6c/0x190 drivers/irqchip/irq-gic-v3.c:969
                    call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891
                    do_interrupt_handler+0xd4/0x138 arch/arm64/kernel/entry-common.c:157
                    __el1_irq arch/arm64/kernel/entry-common.c:519 [inline]
                    el1_interrupt+0x3c/0x60 arch/arm64/kernel/entry-common.c:532
                    el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:537
                    el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:592
                    __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline]
                    arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline]
                    lock_release+0x270/0x39c kernel/locking/lockdep.c:5892
                    __might_fault+0xf0/0x124 mm/memory.c:7081
                    setup_sigframe arch/arm64/kernel/signal.c:1237 [inline]
                    setup_rt_frame arch/arm64/kernel/signal.c:1511 [inline]
                    handle_signal arch/arm64/kernel/signal.c:1559 [inline]
                    arch_do_signal_or_restart+0xb28/0x4414 arch/arm64/kernel/signal.c:1634
                    exit_to_user_mode_loop+0x7c/0x178 kernel/entry/common.c:40
                    exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
                    arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline]
                    el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:747
                    el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765
                    el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
   INITIAL USE at:
                   lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
                   __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
                   _raw_spin_lock_irq+0x58/0x70 kernel/locking/spinlock.c:170
                   spin_lock_irq include/linux/spinlock.h:376 [inline]
                   shmem_add_to_page_cache+0x564/0xa24 mm/shmem.c:887
                   shmem_alloc_and_add_folio+0x73c/0x10b0 mm/shmem.c:1936
                   shmem_get_folio_gfp+0x4d4/0x159c mm/shmem.c:2533
                   shmem_read_folio_gfp+0x8c/0xf0 mm/shmem.c:5931
                   drm_gem_get_pages+0x1cc/0x7c0 drivers/gpu/drm/drm_gem.c:656
                   drm_gem_shmem_get_pages_locked+0x1d4/0x364 drivers/gpu/drm/drm_gem_shmem_helper.c:200
                   drm_gem_shmem_pin_locked+0x1f8/0x410 drivers/gpu/drm/drm_gem_shmem_helper.c:261
                   drm_gem_shmem_vmap_locked+0x3cc/0x658 drivers/gpu/drm/drm_gem_shmem_helper.c:365
                   drm_gem_shmem_object_vmap+0x28/0x38 include/drm/drm_gem_shmem_helper.h:243
                   drm_gem_vmap_locked drivers/gpu/drm/drm_gem.c:1279 [inline]
                   drm_gem_vmap+0x104/0x1d8 drivers/gpu/drm/drm_gem.c:1321
                   drm_client_buffer_vmap+0x48/0x90 drivers/gpu/drm/drm_client.c:312
                   drm_fbdev_shmem_driver_fbdev_probe+0x1d8/0x70c drivers/gpu/drm/drm_fbdev_shmem.c:160
                   drm_fb_helper_single_fb_probe drivers/gpu/drm/drm_fb_helper.c:1650 [inline]
                   __drm_fb_helper_initial_config_and_unlock+0xf94/0x159c drivers/gpu/drm/drm_fb_helper.c:1830
                   drm_fb_helper_initial_config+0x3c/0x58 drivers/gpu/drm/drm_fb_helper.c:1917
                   drm_fbdev_client_hotplug+0x154/0x22c drivers/gpu/drm/clients/drm_fbdev_client.c:52
                   drm_client_register+0x13c/0x1d4 drivers/gpu/drm/drm_client.c:141
                   drm_fbdev_client_setup+0x194/0x3d0 drivers/gpu/drm/clients/drm_fbdev_client.c:159
                   drm_client_setup+0x114/0x228 drivers/gpu/drm/clients/drm_client_setup.c:46
                   vkms_create drivers/gpu/drm/vkms/vkms_drv.c:201 [inline]
                   vkms_init+0x338/0x3f0 drivers/gpu/drm/vkms/vkms_drv.c:221
                   do_one_initcall+0x250/0x990 init/main.c:1283
                   do_initcall_level+0x128/0x1c4 init/main.c:1345
                   do_initcalls+0x70/0xd0 init/main.c:1361
                   do_basic_setup+0x78/0x8c init/main.c:1380
                   kernel_init_freeable+0x268/0x39c init/main.c:1593
                   kernel_init+0x24/0x1dc init/main.c:1483
                   ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844
 }
 ... key      at: [<ffff8000973b6240>] xa_init_flags.__key+0x0/0x20

the dependencies between the lock to be acquired
 and HARDIRQ-irq-unsafe lock:
-> (&p->sequence){+.-.}-{0:0} {
   HARDIRQ-ON-W at:
                    lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
                    do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline]
                    do_write_seqcount_begin include/linux/seqlock.h:503 [inline]
                    fprop_new_period+0x3b8/0x718 lib/flex_proportions.c:74
                    writeout_period+0x94/0x11c mm/page-writeback.c:615
                    call_timer_fn+0x1b4/0x818 kernel/time/timer.c:1747
                    expire_timers kernel/time/timer.c:1798 [inline]
                    __run_timers kernel/time/timer.c:2372 [inline]
                    __run_timer_base+0x51c/0x76c kernel/time/timer.c:2384
                    run_timer_base kernel/time/timer.c:2393 [inline]
                    run_timer_softirq+0x11c/0x194 kernel/time/timer.c:2404
                    handle_softirqs+0x328/0xc88 kernel/softirq.c:622
                    __do_softirq+0x14/0x20 kernel/softirq.c:656
                    ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:68
                    call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891
                    do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:73
                    invoke_softirq kernel/softirq.c:503 [inline]
                    __irq_exit_rcu+0x1b0/0x478 kernel/softirq.c:723
                    irq_exit_rcu+0x14/0x84 kernel/softirq.c:739
                    __el1_irq arch/arm64/kernel/entry-common.c:520 [inline]
                    el1_interrupt+0x40/0x60 arch/arm64/kernel/entry-common.c:532
                    el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:537
                    el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:592
                    __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline]
                    arch_local_irq_restore+0x8/0xc arch/arm64/include/asm/irqflags.h:195
                    lock_is_held include/linux/lockdep.h:249 [inline]
                    __might_resched+0x98/0x4c4 kernel/sched/core.c:8887
                    __might_sleep+0x94/0x110 kernel/sched/core.c:8854
                    try_to_freeze include/linux/freezer.h:54 [inline]
                    get_signal+0xfc/0x12f8 kernel/signal.c:2820
                    arch_do_signal_or_restart+0x1c0/0x4414 arch/arm64/kernel/signal.c:1619
                    exit_to_user_mode_loop+0x7c/0x178 kernel/entry/common.c:40
                    exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
                    arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline]
                    el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:747
                    el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765
                    el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
   IN-SOFTIRQ-W at:
                    lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
                    do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline]
                    do_write_seqcount_begin include/linux/seqlock.h:503 [inline]
                    fprop_new_period+0x3b8/0x718 lib/flex_proportions.c:74
                    writeout_period+0x94/0x11c mm/page-writeback.c:615
                    call_timer_fn+0x1b4/0x818 kernel/time/timer.c:1747
                    expire_timers kernel/time/timer.c:1798 [inline]
                    __run_timers kernel/time/timer.c:2372 [inline]
                    __run_timer_base+0x51c/0x76c kernel/time/timer.c:2384
                    run_timer_base kernel/time/timer.c:2393 [inline]
                    run_timer_softirq+0x11c/0x194 kernel/time/timer.c:2404
                    handle_softirqs+0x328/0xc88 kernel/softirq.c:622
                    __do_softirq+0x14/0x20 kernel/softirq.c:656
                    ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:68
                    call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891
                    do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:73
                    invoke_softirq kernel/softirq.c:503 [inline]
                    __irq_exit_rcu+0x1b0/0x478 kernel/softirq.c:723
                    irq_exit_rcu+0x14/0x84 kernel/softirq.c:739
                    __el1_irq arch/arm64/kernel/entry-common.c:520 [inline]
                    el1_interrupt+0x40/0x60 arch/arm64/kernel/entry-common.c:532
                    el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:537
                    el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:592
                    __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline]
                    arch_local_irq_restore+0x8/0xc arch/arm64/include/asm/irqflags.h:195
                    lock_is_held include/linux/lockdep.h:249 [inline]
                    __might_resched+0x98/0x4c4 kernel/sched/core.c:8887
                    __might_sleep+0x94/0x110 kernel/sched/core.c:8854
                    try_to_freeze include/linux/freezer.h:54 [inline]
                    get_signal+0xfc/0x12f8 kernel/signal.c:2820
                    arch_do_signal_or_restart+0x1c0/0x4414 arch/arm64/kernel/signal.c:1619
                    exit_to_user_mode_loop+0x7c/0x178 kernel/entry/common.c:40
                    exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
                    arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline]
                    el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:747
                    el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765
                    el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
   INITIAL USE at:
                   lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
                   do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline]
                   do_write_seqcount_begin include/linux/seqlock.h:503 [inline]
                   fprop_new_period+0x3b8/0x718 lib/flex_proportions.c:74
                   writeout_period+0x94/0x11c mm/page-writeback.c:615
                   call_timer_fn+0x1b4/0x818 kernel/time/timer.c:1747
                   expire_timers kernel/time/timer.c:1798 [inline]
                   __run_timers kernel/time/timer.c:2372 [inline]
                   __run_timer_base+0x51c/0x76c kernel/time/timer.c:2384
                   run_timer_base kernel/time/timer.c:2393 [inline]
                   run_timer_softirq+0x11c/0x194 kernel/time/timer.c:2404
                   handle_softirqs+0x328/0xc88 kernel/softirq.c:622
                   __do_softirq+0x14/0x20 kernel/softirq.c:656
                   ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:68
                   call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891
                   do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:73
                   invoke_softirq kernel/softirq.c:503 [inline]
                   __irq_exit_rcu+0x1b0/0x478 kernel/softirq.c:723
                   irq_exit_rcu+0x14/0x84 kernel/softirq.c:739
                   __el1_irq arch/arm64/kernel/entry-common.c:520 [inline]
                   el1_interrupt+0x40/0x60 arch/arm64/kernel/entry-common.c:532
                   el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:537
                   el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:592
                   __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline]
                   arch_local_irq_restore+0x8/0xc arch/arm64/include/asm/irqflags.h:195
                   lock_is_held include/linux/lockdep.h:249 [inline]
                   __might_resched+0x98/0x4c4 kernel/sched/core.c:8887
                   __might_sleep+0x94/0x110 kernel/sched/core.c:8854
                   try_to_freeze include/linux/freezer.h:54 [inline]
                   get_signal+0xfc/0x12f8 kernel/signal.c:2820
                   arch_do_signal_or_restart+0x1c0/0x4414 arch/arm64/kernel/signal.c:1619
                   exit_to_user_mode_loop+0x7c/0x178 kernel/entry/common.c:40
                   exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
                   arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline]
                   el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:747
                   el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765
                   el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
   INITIAL READ USE at:
                        lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
                        seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline]
                        fprop_fraction_percpu+0xac/0x270 lib/flex_proportions.c:155
                        __wb_calc_thresh+0xfc/0x3b0 mm/page-writeback.c:913
                        wb_bg_dirty_limits mm/page-writeback.c:2130 [inline]
                        domain_over_bg_thresh+0xb8/0x1f0 mm/page-writeback.c:2144
                        wb_over_bg_thresh+0xf8/0x17c mm/page-writeback.c:2165
                        wb_check_background_flush fs/fs-writeback.c:2257 [inline]
                        wb_do_writeback fs/fs-writeback.c:2355 [inline]
                        wb_workfn+0xa30/0xdc0 fs/fs-writeback.c:2382
                        process_one_work+0x7e8/0x155c kernel/workqueue.c:3263
                        process_scheduled_works kernel/workqueue.c:3346 [inline]
                        worker_thread+0x958/0xed8 kernel/workqueue.c:3427
                        kthread+0x5fc/0x75c kernel/kthread.c:463
                        ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844
 }
 ... key      at: [<ffff800097904a80>] fprop_global_init.__key.1+0x0/0x20
 ... acquired at:
   seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline]
   fprop_fraction_percpu+0xf0/0x270 lib/flex_proportions.c:155
   __fprop_add_percpu_max+0x130/0x1f4 lib/flex_proportions.c:186
   wb_domain_writeout_add mm/page-writeback.c:562 [inline]
   __wb_writeout_add+0xbc/0x27c mm/page-writeback.c:586
   __folio_end_writeback+0x380/0x75c mm/page-writeback.c:3003
   folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1668
   folio_end_writeback+0xd8/0x248 mm/filemap.c:1694
   iomap_finish_folio_write+0x1c0/0x2a4 fs/iomap/buffered-io.c:1582
   fuse_writepage_finish fs/fuse/file.c:1837 [inline]
   fuse_send_writepage fs/fuse/file.c:1887 [inline]
   fuse_flush_writepages+0x54c/0x73c fs/fuse/file.c:1912
   fuse_writepages_send fs/fuse/file.c:2091 [inline]
   fuse_iomap_writeback_range+0x48c/0x152c fs/fuse/file.c:2150
   iomap_writeback_range fs/iomap/buffered-io.c:1593 [inline]
   iomap_writeback_folio+0xee4/0x1c74 fs/iomap/buffered-io.c:1718
   iomap_writepages+0x128/0x25c fs/iomap/buffered-io.c:1770
   fuse_writepages+0x208/0x2bc fs/fuse/file.c:2220
   do_writepages+0x270/0x468 mm/page-writeback.c:2604
   __writeback_single_inode+0x15c/0x13e8 fs/fs-writeback.c:1719
   writeback_single_inode+0x18c/0x54c fs/fs-writeback.c:1840
   write_inode_now+0x13c/0x1a4 fs/fs-writeback.c:2903
   fuse_flush+0x20c/0x6a0 fs/fuse/file.c:460
   filp_flush+0xb8/0x190 fs/open.c:1549
   filp_close+0x28/0x48 fs/open.c:1562
   __range_close fs/file.c:767 [inline]
   __do_sys_close_range fs/file.c:826 [inline]
   __se_sys_close_range fs/file.c:790 [inline]
   __arm64_sys_close_range+0x318/0x5c4 fs/file.c:790
   __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
   invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49
   el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
   do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
   el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:746
   el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765
   el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596


stack backtrace:
CPU: 1 UID: 0 PID: 6832 Comm: syz.4.21 Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 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+0x3058/0x30a4 kernel/locking/lockdep.c:5237
 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
 seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline]
 fprop_fraction_percpu+0xf0/0x270 lib/flex_proportions.c:155
 __fprop_add_percpu_max+0x130/0x1f4 lib/flex_proportions.c:186
 wb_domain_writeout_add mm/page-writeback.c:562 [inline]
 __wb_writeout_add+0xbc/0x27c mm/page-writeback.c:586
 __folio_end_writeback+0x380/0x75c mm/page-writeback.c:3003
 folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1668
 folio_end_writeback+0xd8/0x248 mm/filemap.c:1694
 iomap_finish_folio_write+0x1c0/0x2a4 fs/iomap/buffered-io.c:1582
 fuse_writepage_finish fs/fuse/file.c:1837 [inline]
 fuse_send_writepage fs/fuse/file.c:1887 [inline]
 fuse_flush_writepages+0x54c/0x73c fs/fuse/file.c:1912
 fuse_writepages_send fs/fuse/file.c:2091 [inline]
 fuse_iomap_writeback_range+0x48c/0x152c fs/fuse/file.c:2150
 iomap_writeback_range fs/iomap/buffered-io.c:1593 [inline]
 iomap_writeback_folio+0xee4/0x1c74 fs/iomap/buffered-io.c:1718
 iomap_writepages+0x128/0x25c fs/iomap/buffered-io.c:1770
 fuse_writepages+0x208/0x2bc fs/fuse/file.c:2220
 do_writepages+0x270/0x468 mm/page-writeback.c:2604
 __writeback_single_inode+0x15c/0x13e8 fs/fs-writeback.c:1719
 writeback_single_inode+0x18c/0x54c fs/fs-writeback.c:1840
 write_inode_now+0x13c/0x1a4 fs/fs-writeback.c:2903
 fuse_flush+0x20c/0x6a0 fs/fuse/file.c:460
 filp_flush+0xb8/0x190 fs/open.c:1549
 filp_close+0x28/0x48 fs/open.c:1562
 __range_close fs/file.c:767 [inline]
 __do_sys_close_range fs/file.c:826 [inline]
 __se_sys_close_range fs/file.c:790 [inline]
 __arm64_sys_close_range+0x318/0x5c4 fs/file.c:790
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:746
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596