===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected syzkaller #0 Not tainted ----------------------------------------------------- syz.2.1254/7039 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffff80008d39f6b0 (&p->sequence){+.-.}-{0:0}, at: __fprop_add_percpu_max+0xf8/0x14c lib/flex_proportions.c:186 and this task is already holding: ffff000021494140 (&xa->xa_lock#8){-...}-{3:3}, at: __folio_end_writeback+0x20c/0x85c mm/page-writeback.c:2996 which would create a new lock dependency: (&xa->xa_lock#8){-...}-{3:3} -> (&p->sequence){+.-.}-{0:0} but this new dependency connects a HARDIRQ-irq-safe lock: (&xa->xa_lock#8){-...}-{3:3} ... which became HARDIRQ-irq-safe at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x310/0x38c kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x58/0x80 kernel/locking/spinlock.c:162 __folio_end_writeback+0x20c/0x85c mm/page-writeback.c:2996 folio_end_writeback_no_dropbehind+0x74/0x1dc mm/filemap.c:1668 folio_end_writeback+0xa8/0x1dc mm/filemap.c:1694 end_buffer_async_write+0x194/0x268 fs/buffer.c:419 end_bio_bh_io_sync+0xb8/0x128 fs/buffer.c:2776 bio_endio+0x56c/0x748 block/bio.c:1672 blk_update_request+0x4a0/0x11a4 block/blk-mq.c:998 blk_mq_end_request+0x58/0x338 block/blk-mq.c:1160 virtblk_request_done+0x150/0x23c drivers/block/virtio_blk.c:347 blk_mq_complete_request block/blk-mq.c:1338 [inline] blk_mq_complete_request+0x78/0xa4 block/blk-mq.c:1335 virtblk_done+0x130/0x2d4 drivers/block/virtio_blk.c:366 vring_interrupt drivers/virtio/virtio_ring.c:2718 [inline] vring_interrupt+0x190/0x310 drivers/virtio/virtio_ring.c:2693 __handle_irq_event_percpu+0x19c/0x7f0 kernel/irq/handle.c:203 handle_irq_event_percpu kernel/irq/handle.c:240 [inline] handle_irq_event+0xb0/0x1d8 kernel/irq/handle.c:257 handle_fasteoi_irq+0x2fc/0x97c kernel/irq/chip.c:764 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq_desc+0xd0/0x110 kernel/irq/irqdesc.c:669 generic_handle_domain_irq+0x1c/0x28 kernel/irq/irqdesc.c:725 gic_handle_irq+0x54/0x184 drivers/irqchip/irq-gic.c:370 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_interrupt_handler+0x12c/0x150 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_enable arch/arm64/include/asm/irqflags.h:26 [inline] arch_local_irq_enable arch/arm64/include/asm/irqflags.h:48 [inline] raw_spin_rq_unlock_irq kernel/sched/sched.h:1559 [inline] finish_lock_switch kernel/sched/core.c:5073 [inline] finish_task_switch.isra.0+0x1ac/0x854 kernel/sched/core.c:5191 context_switch kernel/sched/core.c:5328 [inline] __schedule+0xd5c/0x3180 kernel/sched/core.c:6929 preempt_schedule_common kernel/sched/core.c:7113 [inline] preempt_schedule+0xf4/0x254 kernel/sched/core.c:7137 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x6c/0x84 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] lockref_get_not_dead+0x5c/0x78 lib/lockref.c:160 __legitimize_path+0x68/0x164 fs/namei.c:777 legitimize_path fs/namei.c:787 [inline] try_to_unlazy+0xd4/0x4e8 fs/namei.c:848 lookup_fast+0x208/0x4b8 fs/namei.c:1752 walk_component+0x54/0x484 fs/namei.c:2147 link_path_walk+0x408/0xae4 fs/namei.c:2519 path_parentat fs/namei.c:2723 [inline] __filename_parentat+0x17c/0x530 fs/namei.c:2747 filename_parentat fs/namei.c:2765 [inline] do_unlinkat+0xc8/0x494 fs/namei.c:4712 __do_sys_unlinkat fs/namei.c:4778 [inline] __se_sys_unlinkat fs/namei.c:4771 [inline] __arm64_sys_unlinkat+0x8c/0xf4 fs/namei.c:4771 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x288 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0xa0/0xe4 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 kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x310/0x38c kernel/locking/lockdep.c:5825 do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline] do_write_seqcount_begin include/linux/seqlock.h:503 [inline] fprop_new_period+0x9c/0x6e0 lib/flex_proportions.c:74 writeout_period+0x84/0x128 mm/page-writeback.c:615 call_timer_fn+0x1b0/0x7a8 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers+0x778/0x9a8 kernel/time/timer.c:2373 __run_timer_base kernel/time/timer.c:2385 [inline] __run_timer_base kernel/time/timer.c:2377 [inline] run_timer_base+0x110/0x180 kernel/time/timer.c:2394 run_timer_softirq+0x24/0x44 kernel/time/timer.c:2405 handle_softirqs+0x2d8/0xdb4 kernel/softirq.c:622 __do_softirq+0x14/0x20 kernel/softirq.c:656 ____do_softirq+0x10/0x1c arch/arm64/kernel/irq.c:68 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_softirq_own_stack+0x1c/0x2c arch/arm64/kernel/irq.c:73 invoke_softirq kernel/softirq.c:503 [inline] __irq_exit_rcu+0x3f8/0x554 kernel/softirq.c:723 irq_exit_rcu+0x14/0x80 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_enable arch/arm64/include/asm/irqflags.h:26 [inline] arch_local_irq_enable arch/arm64/include/asm/irqflags.h:48 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irq+0x34/0x8c kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] ep_start_scan+0x148/0x3b0 fs/eventpoll.c:747 ep_send_events+0xcc/0x908 fs/eventpoll.c:1782 ep_try_send_events fs/eventpoll.c:1905 [inline] ep_poll fs/eventpoll.c:1970 [inline] do_epoll_wait+0x374/0xd78 fs/eventpoll.c:2473 do_compat_epoll_pwait.part.0+0x14/0xd4 fs/eventpoll.c:2503 do_epoll_pwait fs/eventpoll.c:2500 [inline] __do_sys_epoll_pwait fs/eventpoll.c:2516 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2510 [inline] __arm64_sys_epoll_pwait+0x158/0x248 fs/eventpoll.c:2510 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x288 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0xa0/0xe4 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#8); lock(&p->sequence); lock(&xa->xa_lock#8); *** DEADLOCK *** 5 locks held by syz.2.1254/7039: #0: ffff000012b8aef8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x1e4/0x290 fs/file.c:1232 #1: ffff000022390420 (sb_writers#13){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] #1: ffff000022390420 (sb_writers#13){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1916 [inline] #1: ffff000022390420 (sb_writers#13){.+.+}-{0:0}, at: sb_start_write include/linux/fs.h:2052 [inline] #1: ffff000022390420 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3113 [inline] #1: ffff000022390420 (sb_writers#13){.+.+}-{0:0}, at: vfs_writev+0x4f4/0x6b4 fs/read_write.c:1055 #2: ffff000021494048 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #2: ffff000021494048 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: fuse_fsync+0xdc/0x270 fs/fuse/file.c:528 #3: ffff000021494538 (&fi->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff000021494538 (&fi->lock){+.+.}-{3:3}, at: fuse_writepages_send fs/fuse/file.c:2089 [inline] #3: ffff000021494538 (&fi->lock){+.+.}-{3:3}, at: fuse_iomap_writeback_range+0x390/0x1698 fs/fuse/file.c:2150 #4: ffff000021494140 (&xa->xa_lock#8){-...}-{3:3}, at: __folio_end_writeback+0x20c/0x85c mm/page-writeback.c:2996 the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&xa->xa_lock#8){-...}-{3:3} { IN-HARDIRQ-W at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x310/0x38c kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x58/0x80 kernel/locking/spinlock.c:162 __folio_end_writeback+0x20c/0x85c mm/page-writeback.c:2996 folio_end_writeback_no_dropbehind+0x74/0x1dc mm/filemap.c:1668 folio_end_writeback+0xa8/0x1dc mm/filemap.c:1694 end_buffer_async_write+0x194/0x268 fs/buffer.c:419 end_bio_bh_io_sync+0xb8/0x128 fs/buffer.c:2776 bio_endio+0x56c/0x748 block/bio.c:1672 blk_update_request+0x4a0/0x11a4 block/blk-mq.c:998 blk_mq_end_request+0x58/0x338 block/blk-mq.c:1160 virtblk_request_done+0x150/0x23c drivers/block/virtio_blk.c:347 blk_mq_complete_request block/blk-mq.c:1338 [inline] blk_mq_complete_request+0x78/0xa4 block/blk-mq.c:1335 virtblk_done+0x130/0x2d4 drivers/block/virtio_blk.c:366 vring_interrupt drivers/virtio/virtio_ring.c:2718 [inline] vring_interrupt+0x190/0x310 drivers/virtio/virtio_ring.c:2693 __handle_irq_event_percpu+0x19c/0x7f0 kernel/irq/handle.c:203 handle_irq_event_percpu kernel/irq/handle.c:240 [inline] handle_irq_event+0xb0/0x1d8 kernel/irq/handle.c:257 handle_fasteoi_irq+0x2fc/0x97c kernel/irq/chip.c:764 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq_desc+0xd0/0x110 kernel/irq/irqdesc.c:669 generic_handle_domain_irq+0x1c/0x28 kernel/irq/irqdesc.c:725 gic_handle_irq+0x54/0x184 drivers/irqchip/irq-gic.c:370 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_interrupt_handler+0x12c/0x150 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_enable arch/arm64/include/asm/irqflags.h:26 [inline] arch_local_irq_enable arch/arm64/include/asm/irqflags.h:48 [inline] raw_spin_rq_unlock_irq kernel/sched/sched.h:1559 [inline] finish_lock_switch kernel/sched/core.c:5073 [inline] finish_task_switch.isra.0+0x1ac/0x854 kernel/sched/core.c:5191 context_switch kernel/sched/core.c:5328 [inline] __schedule+0xd5c/0x3180 kernel/sched/core.c:6929 preempt_schedule_common kernel/sched/core.c:7113 [inline] preempt_schedule+0xf4/0x254 kernel/sched/core.c:7137 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x6c/0x84 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] lockref_get_not_dead+0x5c/0x78 lib/lockref.c:160 __legitimize_path+0x68/0x164 fs/namei.c:777 legitimize_path fs/namei.c:787 [inline] try_to_unlazy+0xd4/0x4e8 fs/namei.c:848 lookup_fast+0x208/0x4b8 fs/namei.c:1752 walk_component+0x54/0x484 fs/namei.c:2147 link_path_walk+0x408/0xae4 fs/namei.c:2519 path_parentat fs/namei.c:2723 [inline] __filename_parentat+0x17c/0x530 fs/namei.c:2747 filename_parentat fs/namei.c:2765 [inline] do_unlinkat+0xc8/0x494 fs/namei.c:4712 __do_sys_unlinkat fs/namei.c:4778 [inline] __se_sys_unlinkat fs/namei.c:4771 [inline] __arm64_sys_unlinkat+0x8c/0xf4 fs/namei.c:4771 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x288 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x310/0x38c kernel/locking/lockdep.c:5825 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x54/0x74 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] shmem_add_to_page_cache+0x408/0x77c mm/shmem.c:886 shmem_alloc_and_add_folio+0x350/0xd8c mm/shmem.c:1938 shmem_get_folio_gfp+0x42c/0x113c mm/shmem.c:2535 shmem_read_folio_gfp+0xc8/0x128 mm/shmem.c:5933 drm_gem_get_pages+0x180/0x5f8 drivers/gpu/drm/drm_gem.c:656 drm_gem_shmem_get_pages_locked+0x1b8/0x310 drivers/gpu/drm/drm_gem_shmem_helper.c:200 drm_gem_shmem_pin_locked+0x1dc/0x3d0 drivers/gpu/drm/drm_gem_shmem_helper.c:261 drm_gem_shmem_vmap_locked+0x38c/0x610 drivers/gpu/drm/drm_gem_shmem_helper.c:365 drm_gem_shmem_object_vmap+0x10/0x1c include/drm/drm_gem_shmem_helper.h:243 drm_gem_vmap_locked+0x98/0x140 drivers/gpu/drm/drm_gem.c:1279 drm_gem_vmap+0x4c/0xa4 drivers/gpu/drm/drm_gem.c:1321 drm_client_buffer_vmap+0x44/0xb4 drivers/gpu/drm/drm_client.c:312 drm_fbdev_shmem_driver_fbdev_probe+0x25c/0x7c0 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+0x888/0x120c drivers/gpu/drm/drm_fb_helper.c:1830 drm_fb_helper_initial_config drivers/gpu/drm/drm_fb_helper.c:1917 [inline] drm_fb_helper_initial_config+0x48/0x58 drivers/gpu/drm/drm_fb_helper.c:1909 drm_fbdev_client_hotplug+0x140/0x1fc drivers/gpu/drm/clients/drm_fbdev_client.c:52 drm_client_register+0x12c/0x1ec drivers/gpu/drm/drm_client.c:141 drm_fbdev_client_setup+0x154/0x3f4 drivers/gpu/drm/clients/drm_fbdev_client.c:159 drm_client_setup drivers/gpu/drm/clients/drm_client_setup.c:46 [inline] drm_client_setup+0x150/0x1e8 drivers/gpu/drm/clients/drm_client_setup.c:35 vkms_create drivers/gpu/drm/vkms/vkms_drv.c:201 [inline] vkms_init+0x3c8/0x4d4 drivers/gpu/drm/vkms/vkms_drv.c:221 do_one_initcall+0x130/0x7f0 init/main.c:1283 do_initcall_level init/main.c:1345 [inline] do_initcalls init/main.c:1361 [inline] do_basic_setup init/main.c:1380 [inline] kernel_init_freeable+0x48c/0x714 init/main.c:1593 kernel_init+0x24/0x1dc init/main.c:1483 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 } ... key at: [] __key.4+0x0/0x40 the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (&p->sequence){+.-.}-{0:0} { HARDIRQ-ON-W at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x310/0x38c kernel/locking/lockdep.c:5825 do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline] do_write_seqcount_begin include/linux/seqlock.h:503 [inline] fprop_new_period+0x9c/0x6e0 lib/flex_proportions.c:74 writeout_period+0x84/0x128 mm/page-writeback.c:615 call_timer_fn+0x1b0/0x7a8 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers+0x778/0x9a8 kernel/time/timer.c:2373 __run_timer_base kernel/time/timer.c:2385 [inline] __run_timer_base kernel/time/timer.c:2377 [inline] run_timer_base+0x110/0x180 kernel/time/timer.c:2394 run_timer_softirq+0x24/0x44 kernel/time/timer.c:2405 handle_softirqs+0x2d8/0xdb4 kernel/softirq.c:622 __do_softirq+0x14/0x20 kernel/softirq.c:656 ____do_softirq+0x10/0x1c arch/arm64/kernel/irq.c:68 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_softirq_own_stack+0x1c/0x2c arch/arm64/kernel/irq.c:73 invoke_softirq kernel/softirq.c:503 [inline] __irq_exit_rcu+0x3f8/0x554 kernel/softirq.c:723 irq_exit_rcu+0x14/0x80 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_enable arch/arm64/include/asm/irqflags.h:26 [inline] arch_local_irq_enable arch/arm64/include/asm/irqflags.h:48 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irq+0x34/0x8c kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] ep_start_scan+0x148/0x3b0 fs/eventpoll.c:747 ep_send_events+0xcc/0x908 fs/eventpoll.c:1782 ep_try_send_events fs/eventpoll.c:1905 [inline] ep_poll fs/eventpoll.c:1970 [inline] do_epoll_wait+0x374/0xd78 fs/eventpoll.c:2473 do_compat_epoll_pwait.part.0+0x14/0xd4 fs/eventpoll.c:2503 do_epoll_pwait fs/eventpoll.c:2500 [inline] __do_sys_epoll_pwait fs/eventpoll.c:2516 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2510 [inline] __arm64_sys_epoll_pwait+0x158/0x248 fs/eventpoll.c:2510 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x288 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 IN-SOFTIRQ-W at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x310/0x38c kernel/locking/lockdep.c:5825 do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline] do_write_seqcount_begin include/linux/seqlock.h:503 [inline] fprop_new_period+0x9c/0x6e0 lib/flex_proportions.c:74 writeout_period+0x84/0x128 mm/page-writeback.c:615 call_timer_fn+0x1b0/0x7a8 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers+0x778/0x9a8 kernel/time/timer.c:2373 __run_timer_base kernel/time/timer.c:2385 [inline] __run_timer_base kernel/time/timer.c:2377 [inline] run_timer_base+0x110/0x180 kernel/time/timer.c:2394 run_timer_softirq+0x24/0x44 kernel/time/timer.c:2405 handle_softirqs+0x2d8/0xdb4 kernel/softirq.c:622 __do_softirq+0x14/0x20 kernel/softirq.c:656 ____do_softirq+0x10/0x1c arch/arm64/kernel/irq.c:68 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_softirq_own_stack+0x1c/0x2c arch/arm64/kernel/irq.c:73 invoke_softirq kernel/softirq.c:503 [inline] __irq_exit_rcu+0x3f8/0x554 kernel/softirq.c:723 irq_exit_rcu+0x14/0x80 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_enable arch/arm64/include/asm/irqflags.h:26 [inline] arch_local_irq_enable arch/arm64/include/asm/irqflags.h:48 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irq+0x34/0x8c kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] ep_start_scan+0x148/0x3b0 fs/eventpoll.c:747 ep_send_events+0xcc/0x908 fs/eventpoll.c:1782 ep_try_send_events fs/eventpoll.c:1905 [inline] ep_poll fs/eventpoll.c:1970 [inline] do_epoll_wait+0x374/0xd78 fs/eventpoll.c:2473 do_compat_epoll_pwait.part.0+0x14/0xd4 fs/eventpoll.c:2503 do_epoll_pwait fs/eventpoll.c:2500 [inline] __do_sys_epoll_pwait fs/eventpoll.c:2516 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2510 [inline] __arm64_sys_epoll_pwait+0x158/0x248 fs/eventpoll.c:2510 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x288 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x310/0x38c kernel/locking/lockdep.c:5825 do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline] do_write_seqcount_begin include/linux/seqlock.h:503 [inline] fprop_new_period+0x9c/0x6e0 lib/flex_proportions.c:74 writeout_period+0x84/0x128 mm/page-writeback.c:615 call_timer_fn+0x1b0/0x7a8 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers+0x778/0x9a8 kernel/time/timer.c:2373 __run_timer_base kernel/time/timer.c:2385 [inline] __run_timer_base kernel/time/timer.c:2377 [inline] run_timer_base+0x110/0x180 kernel/time/timer.c:2394 run_timer_softirq+0x24/0x44 kernel/time/timer.c:2405 handle_softirqs+0x2d8/0xdb4 kernel/softirq.c:622 __do_softirq+0x14/0x20 kernel/softirq.c:656 ____do_softirq+0x10/0x1c arch/arm64/kernel/irq.c:68 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_softirq_own_stack+0x1c/0x2c arch/arm64/kernel/irq.c:73 invoke_softirq kernel/softirq.c:503 [inline] __irq_exit_rcu+0x3f8/0x554 kernel/softirq.c:723 irq_exit_rcu+0x14/0x80 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_enable arch/arm64/include/asm/irqflags.h:26 [inline] arch_local_irq_enable arch/arm64/include/asm/irqflags.h:48 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irq+0x34/0x8c kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] ep_start_scan+0x148/0x3b0 fs/eventpoll.c:747 ep_send_events+0xcc/0x908 fs/eventpoll.c:1782 ep_try_send_events fs/eventpoll.c:1905 [inline] ep_poll fs/eventpoll.c:1970 [inline] do_epoll_wait+0x374/0xd78 fs/eventpoll.c:2473 do_compat_epoll_pwait.part.0+0x14/0xd4 fs/eventpoll.c:2503 do_epoll_pwait fs/eventpoll.c:2500 [inline] __do_sys_epoll_pwait fs/eventpoll.c:2516 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2510 [inline] __arm64_sys_epoll_pwait+0x158/0x248 fs/eventpoll.c:2510 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x288 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x310/0x38c kernel/locking/lockdep.c:5825 seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline] fprop_fraction_percpu+0x1f4/0x280 lib/flex_proportions.c:155 __wb_calc_thresh+0xf4/0x3c4 mm/page-writeback.c:913 wb_bg_dirty_limits mm/page-writeback.c:2130 [inline] domain_over_bg_thresh+0xa8/0x218 mm/page-writeback.c:2144 wb_over_bg_thresh+0xd4/0x13c 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+0x528/0xa9c fs/fs-writeback.c:2382 process_one_work+0x7cc/0x18d4 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x734/0xb84 kernel/workqueue.c:3427 kthread+0x348/0x5fc kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 } ... key at: [] __key.2+0x0/0x40 ... acquired at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x310/0x38c kernel/locking/lockdep.c:5825 seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline] fprop_fraction_percpu+0xb4/0x280 lib/flex_proportions.c:155 __fprop_add_percpu_max+0xf8/0x14c lib/flex_proportions.c:186 wb_domain_writeout_add mm/page-writeback.c:562 [inline] __wb_writeout_add mm/page-writeback.c:586 [inline] __folio_end_writeback+0x3fc/0x85c mm/page-writeback.c:3003 folio_end_writeback_no_dropbehind+0x74/0x1dc mm/filemap.c:1668 folio_end_writeback+0xa8/0x1dc mm/filemap.c:1694 iomap_finish_folio_write+0x154/0x250 fs/iomap/buffered-io.c:1582 fuse_writepage_finish+0xc0/0x154 fs/fuse/file.c:1837 fuse_send_writepage fs/fuse/file.c:1887 [inline] fuse_flush_writepages+0x3b8/0x4f4 fs/fuse/file.c:1912 fuse_writepages_send fs/fuse/file.c:2091 [inline] fuse_iomap_writeback_range+0x434/0x1698 fs/fuse/file.c:2150 iomap_writeback_range fs/iomap/buffered-io.c:1593 [inline] iomap_writeback_folio+0x47c/0x190c fs/iomap/buffered-io.c:1718 iomap_writepages+0x114/0x250 fs/iomap/buffered-io.c:1770 fuse_writepages+0x1dc/0x278 fs/fuse/file.c:2220 do_writepages+0x1fc/0x4b8 mm/page-writeback.c:2604 filemap_fdatawrite_wbc mm/filemap.c:389 [inline] filemap_fdatawrite_wbc+0xdc/0x124 mm/filemap.c:379 __filemap_fdatawrite_range+0xb8/0xfc mm/filemap.c:422 file_write_and_wait_range+0xa8/0x124 mm/filemap.c:797 fuse_fsync+0xec/0x270 fs/fuse/file.c:535 vfs_fsync_range+0xcc/0x1f0 fs/sync.c:187 generic_write_sync include/linux/fs.h:3048 [inline] fuse_cache_write_iter fs/fuse/file.c:1470 [inline] fuse_file_write_iter+0x558/0x6e4 fs/fuse/file.c:1783 do_iter_readv_writev+0x3c8/0x644 fs/read_write.c:827 vfs_writev+0x240/0x6b4 fs/read_write.c:1057 do_writev+0xf8/0x278 fs/read_write.c:1103 __do_sys_writev fs/read_write.c:1171 [inline] __se_sys_writev fs/read_write.c:1168 [inline] __arm64_sys_writev+0x70/0xa0 fs/read_write.c:1168 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132 do_el0_svc_compat+0x40/0x68 arch/arm64/kernel/syscall.c:157 el0_svc_compat+0x50/0x248 arch/arm64/kernel/entry-common.c:897 el0t_32_sync_handler+0x88/0xac arch/arm64/kernel/entry-common.c:915 el0t_32_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:601 stack backtrace: CPU: 1 UID: 0 PID: 7039 Comm: syz.2.1254 Not tainted syzkaller #0 PREEMPT Hardware name: linux,dummy-virt (DT) Call trace: show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xa4/0xf4 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+0x78c/0xadc kernel/locking/lockdep.c:2857 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+0x1650/0x2380 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x310/0x38c kernel/locking/lockdep.c:5825 seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline] fprop_fraction_percpu+0xb4/0x280 lib/flex_proportions.c:155 __fprop_add_percpu_max+0xf8/0x14c lib/flex_proportions.c:186 wb_domain_writeout_add mm/page-writeback.c:562 [inline] __wb_writeout_add mm/page-writeback.c:586 [inline] __folio_end_writeback+0x3fc/0x85c mm/page-writeback.c:3003 folio_end_writeback_no_dropbehind+0x74/0x1dc mm/filemap.c:1668 folio_end_writeback+0xa8/0x1dc mm/filemap.c:1694 iomap_finish_folio_write+0x154/0x250 fs/iomap/buffered-io.c:1582 fuse_writepage_finish+0xc0/0x154 fs/fuse/file.c:1837 fuse_send_writepage fs/fuse/file.c:1887 [inline] fuse_flush_writepages+0x3b8/0x4f4 fs/fuse/file.c:1912 fuse_writepages_send fs/fuse/file.c:2091 [inline] fuse_iomap_writeback_range+0x434/0x1698 fs/fuse/file.c:2150 iomap_writeback_range fs/iomap/buffered-io.c:1593 [inline] iomap_writeback_folio+0x47c/0x190c fs/iomap/buffered-io.c:1718 iomap_writepages+0x114/0x250 fs/iomap/buffered-io.c:1770 fuse_writepages+0x1dc/0x278 fs/fuse/file.c:2220 do_writepages+0x1fc/0x4b8 mm/page-writeback.c:2604 filemap_fdatawrite_wbc mm/filemap.c:389 [inline] filemap_fdatawrite_wbc+0xdc/0x124 mm/filemap.c:379 __filemap_fdatawrite_range+0xb8/0xfc mm/filemap.c:422 file_write_and_wait_range+0xa8/0x124 mm/filemap.c:797 fuse_fsync+0xec/0x270 fs/fuse/file.c:535 vfs_fsync_range+0xcc/0x1f0 fs/sync.c:187 generic_write_sync include/linux/fs.h:3048 [inline] fuse_cache_write_iter fs/fuse/file.c:1470 [inline] fuse_file_write_iter+0x558/0x6e4 fs/fuse/file.c:1783 do_iter_readv_writev+0x3c8/0x644 fs/read_write.c:827 vfs_writev+0x240/0x6b4 fs/read_write.c:1057 do_writev+0xf8/0x278 fs/read_write.c:1103 __do_sys_writev fs/read_write.c:1171 [inline] __se_sys_writev fs/read_write.c:1168 [inline] __arm64_sys_writev+0x70/0xa0 fs/read_write.c:1168 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132 do_el0_svc_compat+0x40/0x68 arch/arm64/kernel/syscall.c:157 el0_svc_compat+0x50/0x248 arch/arm64/kernel/entry-common.c:897 el0t_32_sync_handler+0x88/0xac arch/arm64/kernel/entry-common.c:915 el0t_32_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:601