===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected syzkaller #0 Not tainted ----------------------------------------------------- syz.0.41/6847 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffff800097625150 (&p->sequence){+.-.}-{0:0}, at: __fprop_add_percpu_max+0x130/0x1f4 lib/flex_proportions.c:186 and this task is already holding: ffff0000e1368240 (&xa->xa_lock#10){..-.}-{3:3}, at: __folio_end_writeback+0x10c/0x6f8 mm/page-writeback.c:2990 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: (&fq->mq_flush_lock){-.-.}-{3:3} ... which became HARDIRQ-irq-safe at: lock_acquire+0x140/0x2e0 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 flush_end_io+0xb4/0xd68 block/blk-flush.c:211 __blk_mq_end_request+0x37c/0x57c block/blk-mq.c:1159 blk_mq_end_request+0x68/0x88 block/blk-mq.c:1171 nvme_end_req drivers/nvme/host/core.c:454 [inline] nvme_complete_rq+0x150/0x464 drivers/nvme/host/core.c:-1 nvme_pci_complete_rq drivers/nvme/host/pci.c:1343 [inline] nvme_handle_cqe drivers/nvme/host/pci.c:1407 [inline] nvme_poll_cq+0x644/0x1018 drivers/nvme/host/pci.c:1434 nvme_irq+0x90/0x240 drivers/nvme/host/pci.c:1448 __handle_irq_event_percpu+0x20c/0x8e4 kernel/irq/handle.c:211 handle_irq_event_percpu kernel/irq/handle.c:248 [inline] handle_irq_event+0x9c/0x1d0 kernel/irq/handle.c:265 handle_fasteoi_irq+0x328/0x8d8 kernel/irq/chip.c:764 generic_handle_irq_desc include/linux/irqdesc.h:172 [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:825 [inline] __gic_handle_irq_from_irqson drivers/irqchip/irq-gic-v3.c:876 [inline] gic_handle_irq+0x6c/0x18c drivers/irqchip/irq-gic-v3.c:920 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_interrupt_handler+0xd4/0x138 arch/arm64/kernel/entry-common.c:135 __el1_irq arch/arm64/kernel/entry-common.c:497 [inline] el1_interrupt+0x3c/0x60 arch/arm64/kernel/entry-common.c:510 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:515 el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:592 __sanitizer_cov_trace_switch+0x8/0xe4 kernel/kcov.c:331 tomoyo_supervisor+0x114/0x1224 security/tomoyo/common.c:2170 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline] tomoyo_path_permission+0x1e8/0x310 security/tomoyo/file.c:587 tomoyo_check_open_permission+0x244/0x31c security/tomoyo/file.c:780 tomoyo_file_open+0x154/0x1ec security/tomoyo/tomoyo.c:334 security_file_open+0xc8/0x298 security/security.c:2636 do_dentry_open+0x2ac/0x1154 fs/open.c:939 vfs_open+0x44/0x2d4 fs/open.c:1094 do_open fs/namei.c:4628 [inline] path_openat+0x2890/0x3114 fs/namei.c:4787 do_filp_open+0x18c/0x36c fs/namei.c:4814 do_sys_openat2+0x11c/0x1f0 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __arm64_sys_openat+0x120/0x158 fs/open.c:1447 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 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+0x140/0x2e0 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+0x19c/0x814 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x51c/0x76c kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0x11c/0x194 kernel/time/timer.c:2405 handle_softirqs+0x31c/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:498 [inline] el1_interrupt+0x40/0x60 arch/arm64/kernel/entry-common.c:510 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:515 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+0x34/0x80 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] loop_queue_work drivers/block/loop.c:864 [inline] loop_queue_rq+0x94c/0xaa8 drivers/block/loop.c:1890 __blk_mq_issue_directly block/blk-mq.c:2715 [inline] blk_mq_request_issue_directly+0x2c0/0x560 block/blk-mq.c:2802 blk_mq_issue_direct+0x254/0x558 block/blk-mq.c:2823 blk_mq_dispatch_queue_requests+0x568/0x674 block/blk-mq.c:2898 blk_mq_flush_plug_list+0x370/0x488 block/blk-mq.c:2981 __blk_flush_plug+0x330/0x408 block/blk-core.c:1225 blk_finish_plug+0x68/0x90 block/blk-core.c:1252 wb_writeback+0xd04/0xd70 fs/fs-writeback.c:2254 wb_do_writeback fs/fs-writeback.c:2363 [inline] wb_workfn+0x320/0xdc0 fs/fs-writeback.c:2403 process_one_work+0x7c0/0x1558 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3421 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 other info that might help us debug this: Chain exists of: &fq->mq_flush_lock --> &xa->xa_lock#10 --> &p->sequence Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->sequence); local_irq_disable(); lock(&fq->mq_flush_lock); lock(&xa->xa_lock#10); lock(&fq->mq_flush_lock); *** DEADLOCK *** 2 locks held by syz.0.41/6847: #0: ffff0000e1368638 (&fi->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #0: ffff0000e1368638 (&fi->lock){+.+.}-{3:3}, at: fuse_writepage_end+0x138/0x454 fs/fuse/file.c:2001 #1: ffff0000e1368240 (&xa->xa_lock#10){..-.}-{3:3}, at: __folio_end_writeback+0x10c/0x6f8 mm/page-writeback.c:2990 the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&fq->mq_flush_lock){-.-.}-{3:3} { IN-HARDIRQ-W at: lock_acquire+0x140/0x2e0 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 flush_end_io+0xb4/0xd68 block/blk-flush.c:211 __blk_mq_end_request+0x37c/0x57c block/blk-mq.c:1159 blk_mq_end_request+0x68/0x88 block/blk-mq.c:1171 nvme_end_req drivers/nvme/host/core.c:454 [inline] nvme_complete_rq+0x150/0x464 drivers/nvme/host/core.c:-1 nvme_pci_complete_rq drivers/nvme/host/pci.c:1343 [inline] nvme_handle_cqe drivers/nvme/host/pci.c:1407 [inline] nvme_poll_cq+0x644/0x1018 drivers/nvme/host/pci.c:1434 nvme_irq+0x90/0x240 drivers/nvme/host/pci.c:1448 __handle_irq_event_percpu+0x20c/0x8e4 kernel/irq/handle.c:211 handle_irq_event_percpu kernel/irq/handle.c:248 [inline] handle_irq_event+0x9c/0x1d0 kernel/irq/handle.c:265 handle_fasteoi_irq+0x328/0x8d8 kernel/irq/chip.c:764 generic_handle_irq_desc include/linux/irqdesc.h:172 [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:825 [inline] __gic_handle_irq_from_irqson drivers/irqchip/irq-gic-v3.c:876 [inline] gic_handle_irq+0x6c/0x18c drivers/irqchip/irq-gic-v3.c:920 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_interrupt_handler+0xd4/0x138 arch/arm64/kernel/entry-common.c:135 __el1_irq arch/arm64/kernel/entry-common.c:497 [inline] el1_interrupt+0x3c/0x60 arch/arm64/kernel/entry-common.c:510 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:515 el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:592 __sanitizer_cov_trace_switch+0x8/0xe4 kernel/kcov.c:331 tomoyo_supervisor+0x114/0x1224 security/tomoyo/common.c:2170 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline] tomoyo_path_permission+0x1e8/0x310 security/tomoyo/file.c:587 tomoyo_check_open_permission+0x244/0x31c security/tomoyo/file.c:780 tomoyo_file_open+0x154/0x1ec security/tomoyo/tomoyo.c:334 security_file_open+0xc8/0x298 security/security.c:2636 do_dentry_open+0x2ac/0x1154 fs/open.c:939 vfs_open+0x44/0x2d4 fs/open.c:1094 do_open fs/namei.c:4628 [inline] path_openat+0x2890/0x3114 fs/namei.c:4787 do_filp_open+0x18c/0x36c fs/namei.c:4814 do_sys_openat2+0x11c/0x1f0 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __arm64_sys_openat+0x120/0x158 fs/open.c:1447 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 IN-SOFTIRQ-W at: lock_acquire+0x140/0x2e0 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 flush_end_io+0xb4/0xd68 block/blk-flush.c:211 __blk_mq_end_request+0x37c/0x57c block/blk-mq.c:1159 blk_mq_end_request+0x68/0x88 block/blk-mq.c:1171 lo_complete_rq+0x124/0x274 drivers/block/loop.c:314 blk_complete_reqs block/blk-mq.c:1244 [inline] blk_done_softirq+0x11c/0x168 block/blk-mq.c:1249 handle_softirqs+0x31c/0xc88 kernel/softirq.c:622 run_ksoftirqd+0x70/0xc0 kernel/softirq.c:1063 smpboot_thread_fn+0x4d8/0x9cc kernel/smpboot.c:160 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 INITIAL USE at: lock_acquire+0x140/0x2e0 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] blk_insert_flush+0x360/0x4b8 block/blk-flush.c:454 blk_mq_submit_bio+0x1668/0x21e8 block/blk-mq.c:3229 __submit_bio+0x1d8/0x4d8 block/blk-core.c:637 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x274/0x990 block/blk-core.c:755 submit_bio_noacct+0xdc0/0x186c block/blk-core.c:879 submit_bio+0x3b4/0x550 block/blk-core.c:921 submit_bio_wait+0x104/0x208 block/bio.c:1391 blkdev_issue_flush+0xb4/0x100 block/blk-flush.c:473 ext4_init_inode_table+0x420/0x780 fs/ext4/ialloc.c:1602 ext4_run_li_request fs/ext4/super.c:3732 [inline] ext4_lazyinit_thread+0x6dc/0x1730 fs/ext4/super.c:3827 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 } ... key at: [] blk_alloc_flush_queue.__key+0x0/0x20 -> (&xa->xa_lock#10){..-.}-{3:3} { IN-SOFTIRQ-W at: lock_acquire+0x140/0x2e0 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/0x6f8 mm/page-writeback.c:2990 folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1661 folio_end_writeback+0xd8/0x248 mm/filemap.c:1687 ext4_finish_bio+0x570/0x8a4 fs/ext4/page-io.c:144 ext4_end_bio+0x360/0x610 fs/ext4/page-io.c:-1 bio_endio+0x8d4/0x910 block/bio.c:1675 blk_update_request+0x474/0xba8 block/blk-mq.c:1007 blk_mq_end_request+0x54/0x88 block/blk-mq.c:1169 lo_complete_rq+0x124/0x274 drivers/block/loop.c:314 blk_complete_reqs block/blk-mq.c:1244 [inline] blk_done_softirq+0x11c/0x168 block/blk-mq.c:1249 handle_softirqs+0x31c/0xc88 kernel/softirq.c:622 run_ksoftirqd+0x70/0xc0 kernel/softirq.c:1063 smpboot_thread_fn+0x4d8/0x9cc kernel/smpboot.c:160 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 INITIAL USE at: lock_acquire+0x140/0x2e0 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:904 shmem_alloc_and_add_folio+0x758/0x10c4 mm/shmem.c:1958 shmem_get_folio_gfp+0x4d4/0x159c mm/shmem.c:2556 shmem_read_folio_gfp+0x8c/0xf0 mm/shmem.c:5974 drm_gem_get_pages+0x1cc/0x7c0 drivers/gpu/drm/drm_gem.c:654 drm_gem_shmem_get_pages_locked+0x1d4/0x364 drivers/gpu/drm/drm_gem_shmem_helper.c:239 drm_gem_shmem_pin_locked+0x1f8/0x410 drivers/gpu/drm/drm_gem_shmem_helper.c:300 drm_gem_shmem_vmap_locked+0x3cc/0x658 drivers/gpu/drm/drm_gem_shmem_helper.c:404 drm_gem_shmem_object_vmap+0x28/0x38 include/drm/drm_gem_shmem_helper.h:245 drm_gem_vmap_locked drivers/gpu/drm/drm_gem.c:1269 [inline] drm_gem_vmap+0x104/0x1d8 drivers/gpu/drm/drm_gem.c:1311 drm_client_buffer_vmap+0x68/0xb0 drivers/gpu/drm/drm_client.c:355 drm_fbdev_shmem_driver_fbdev_probe+0x1f4/0x700 drivers/gpu/drm/drm_fbdev_shmem.c:159 drm_fb_helper_single_fb_probe drivers/gpu/drm/drm_fb_helper.c:1562 [inline] __drm_fb_helper_initial_config_and_unlock+0x108c/0x1728 drivers/gpu/drm/drm_fb_helper.c:1741 drm_fb_helper_initial_config+0x3c/0x58 drivers/gpu/drm/drm_fb_helper.c:1828 drm_fbdev_client_hotplug+0x154/0x22c drivers/gpu/drm/clients/drm_fbdev_client.c:66 drm_client_register+0x13c/0x1d4 drivers/gpu/drm/drm_client.c:143 drm_fbdev_client_setup+0x194/0x3d0 drivers/gpu/drm/clients/drm_fbdev_client.c:168 drm_client_setup+0x114/0x228 drivers/gpu/drm/clients/drm_client_setup.c:46 vkms_create+0x370/0x420 drivers/gpu/drm/vkms/vkms_drv.c:211 vkms_init+0x64/0x9c drivers/gpu/drm/vkms/vkms_drv.c:239 do_one_initcall+0x248/0x9b4 init/main.c:1378 do_initcall_level+0x128/0x1c4 init/main.c:1440 do_initcalls+0x70/0xd0 init/main.c:1456 do_basic_setup+0x78/0x8c init/main.c:1475 kernel_init_freeable+0x268/0x39c init/main.c:1688 kernel_init+0x24/0x1dc init/main.c:1578 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 } ... key at: [] xa_init_flags.__key+0x0/0x20 ... acquired at: __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/0x6f8 mm/page-writeback.c:2990 folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1661 folio_end_writeback+0xd8/0x248 mm/filemap.c:1687 f2fs_write_end_io+0x6c0/0xa78 fs/f2fs/data.c:362 bio_endio+0x8d4/0x910 block/bio.c:1675 blk_update_request+0x474/0xba8 block/blk-mq.c:1007 blk_mq_end_request+0x54/0x88 block/blk-mq.c:1169 blk_flush_complete_seq+0x57c/0xad4 block/blk-flush.c:191 flush_end_io+0x9e8/0xd68 block/blk-flush.c:250 __blk_mq_end_request+0x37c/0x57c block/blk-mq.c:1159 blk_mq_end_request+0x68/0x88 block/blk-mq.c:1171 lo_complete_rq+0x124/0x274 drivers/block/loop.c:314 blk_complete_reqs block/blk-mq.c:1244 [inline] blk_done_softirq+0x11c/0x168 block/blk-mq.c:1249 handle_softirqs+0x31c/0xc88 kernel/softirq.c:622 run_ksoftirqd+0x70/0xc0 kernel/softirq.c:1063 smpboot_thread_fn+0x4d8/0x9cc kernel/smpboot.c:160 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (&p->sequence){+.-.}-{0:0} { HARDIRQ-ON-W at: lock_acquire+0x140/0x2e0 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+0x19c/0x814 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x51c/0x76c kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0x11c/0x194 kernel/time/timer.c:2405 handle_softirqs+0x31c/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:498 [inline] el1_interrupt+0x40/0x60 arch/arm64/kernel/entry-common.c:510 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:515 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+0x34/0x80 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] loop_queue_work drivers/block/loop.c:864 [inline] loop_queue_rq+0x94c/0xaa8 drivers/block/loop.c:1890 __blk_mq_issue_directly block/blk-mq.c:2715 [inline] blk_mq_request_issue_directly+0x2c0/0x560 block/blk-mq.c:2802 blk_mq_issue_direct+0x254/0x558 block/blk-mq.c:2823 blk_mq_dispatch_queue_requests+0x568/0x674 block/blk-mq.c:2898 blk_mq_flush_plug_list+0x370/0x488 block/blk-mq.c:2981 __blk_flush_plug+0x330/0x408 block/blk-core.c:1225 blk_finish_plug+0x68/0x90 block/blk-core.c:1252 wb_writeback+0xd04/0xd70 fs/fs-writeback.c:2254 wb_do_writeback fs/fs-writeback.c:2363 [inline] wb_workfn+0x320/0xdc0 fs/fs-writeback.c:2403 process_one_work+0x7c0/0x1558 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3421 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 IN-SOFTIRQ-W at: lock_acquire+0x140/0x2e0 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+0x19c/0x814 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x51c/0x76c kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0x11c/0x194 kernel/time/timer.c:2405 handle_softirqs+0x31c/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:498 [inline] el1_interrupt+0x40/0x60 arch/arm64/kernel/entry-common.c:510 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:515 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+0x34/0x80 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] loop_queue_work drivers/block/loop.c:864 [inline] loop_queue_rq+0x94c/0xaa8 drivers/block/loop.c:1890 __blk_mq_issue_directly block/blk-mq.c:2715 [inline] blk_mq_request_issue_directly+0x2c0/0x560 block/blk-mq.c:2802 blk_mq_issue_direct+0x254/0x558 block/blk-mq.c:2823 blk_mq_dispatch_queue_requests+0x568/0x674 block/blk-mq.c:2898 blk_mq_flush_plug_list+0x370/0x488 block/blk-mq.c:2981 __blk_flush_plug+0x330/0x408 block/blk-core.c:1225 blk_finish_plug+0x68/0x90 block/blk-core.c:1252 wb_writeback+0xd04/0xd70 fs/fs-writeback.c:2254 wb_do_writeback fs/fs-writeback.c:2363 [inline] wb_workfn+0x320/0xdc0 fs/fs-writeback.c:2403 process_one_work+0x7c0/0x1558 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3421 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 INITIAL USE at: lock_acquire+0x140/0x2e0 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+0x19c/0x814 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x51c/0x76c kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0x11c/0x194 kernel/time/timer.c:2405 handle_softirqs+0x31c/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:498 [inline] el1_interrupt+0x40/0x60 arch/arm64/kernel/entry-common.c:510 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:515 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+0x34/0x80 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] loop_queue_work drivers/block/loop.c:864 [inline] loop_queue_rq+0x94c/0xaa8 drivers/block/loop.c:1890 __blk_mq_issue_directly block/blk-mq.c:2715 [inline] blk_mq_request_issue_directly+0x2c0/0x560 block/blk-mq.c:2802 blk_mq_issue_direct+0x254/0x558 block/blk-mq.c:2823 blk_mq_dispatch_queue_requests+0x568/0x674 block/blk-mq.c:2898 blk_mq_flush_plug_list+0x370/0x488 block/blk-mq.c:2981 __blk_flush_plug+0x330/0x408 block/blk-core.c:1225 blk_finish_plug+0x68/0x90 block/blk-core.c:1252 wb_writeback+0xd04/0xd70 fs/fs-writeback.c:2254 wb_do_writeback fs/fs-writeback.c:2363 [inline] wb_workfn+0x320/0xdc0 fs/fs-writeback.c:2403 process_one_work+0x7c0/0x1558 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3421 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 INITIAL READ USE at: lock_acquire+0x140/0x2e0 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:2278 [inline] wb_do_writeback fs/fs-writeback.c:2376 [inline] wb_workfn+0xa30/0xdc0 fs/fs-writeback.c:2403 process_one_work+0x7c0/0x1558 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3421 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 } ... key at: [] 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+0x380/0x6f8 mm/page-writeback.c:2997 folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1661 folio_end_writeback+0xd8/0x248 mm/filemap.c:1687 iomap_finish_folio_write+0x1c0/0x2a4 fs/iomap/buffered-io.c:1713 fuse_writepage_finish fs/fuse/file.c:1903 [inline] fuse_writepage_end+0x238/0x454 fs/fuse/file.c:2003 fuse_request_end+0x898/0xc10 fs/fuse/dev.c:507 fuse_dev_end_requests fs/fuse/dev.c:2415 [inline] fuse_abort_conn+0xe88/0x10a0 fs/fuse/dev.c:2513 fuse_dev_release+0x430/0x4c8 fs/fuse/dev.c:2556 __fput+0x340/0x75c fs/file_table.c:468 ____fput+0x20/0x58 fs/file_table.c:496 task_work_run+0x1dc/0x260 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x52c/0x1a1c kernel/exit.c:971 __do_sys_exit kernel/exit.c:1079 [inline] __se_sys_exit kernel/exit.c:1077 [inline] do_group_exit+0x0/0x22c kernel/exit.c:1077 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 stack backtrace: CPU: 1 UID: 0 PID: 6847 Comm: syz.0.41 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 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+0x140/0x2e0 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+0x380/0x6f8 mm/page-writeback.c:2997 folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1661 folio_end_writeback+0xd8/0x248 mm/filemap.c:1687 iomap_finish_folio_write+0x1c0/0x2a4 fs/iomap/buffered-io.c:1713 fuse_writepage_finish fs/fuse/file.c:1903 [inline] fuse_writepage_end+0x238/0x454 fs/fuse/file.c:2003 fuse_request_end+0x898/0xc10 fs/fuse/dev.c:507 fuse_dev_end_requests fs/fuse/dev.c:2415 [inline] fuse_abort_conn+0xe88/0x10a0 fs/fuse/dev.c:2513 fuse_dev_release+0x430/0x4c8 fs/fuse/dev.c:2556 __fput+0x340/0x75c fs/file_table.c:468 ____fput+0x20/0x58 fs/file_table.c:496 task_work_run+0x1dc/0x260 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x52c/0x1a1c kernel/exit.c:971 __do_sys_exit kernel/exit.c:1079 [inline] __se_sys_exit kernel/exit.c:1077 [inline] do_group_exit+0x0/0x22c kernel/exit.c:1077 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596