===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected syzkaller #0 Not tainted ----------------------------------------------------- syz.0.0/5341 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffffffff995bb110 (&p->sequence){+.-.}-{0:0}, at: __fprop_add_percpu_max+0x10d/0x210 lib/flex_proportions.c:186 and this task is already holding: ffff88801f374240 (&xa->xa_lock#12){-...}-{3:3}, at: __folio_end_writeback+0x1da/0x950 mm/page-writeback.c:2996 which would create a new lock dependency: (&xa->xa_lock#12){-...}-{3:3} -> (&p->sequence){+.-.}-{0:0} but this new dependency connects a HARDIRQ-irq-safe lock: (&xa->xa_lock#12){-...}-{3:3} ... which became HARDIRQ-irq-safe at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 __folio_end_writeback+0x1da/0x950 mm/page-writeback.c:2996 folio_end_writeback_no_dropbehind+0x151/0x290 mm/filemap.c:1668 folio_end_writeback+0xea/0x220 mm/filemap.c:1694 end_bio_bh_io_sync+0xbd/0x120 fs/buffer.c:2776 blk_update_request+0x57e/0xe60 block/blk-mq.c:998 scsi_end_request+0x7c/0x830 drivers/scsi/scsi_lib.c:637 scsi_io_completion+0x131/0x390 drivers/scsi/scsi_lib.c:1078 ata_qc_complete_multiple+0x1ae/0x280 drivers/ata/libata-sata.c:789 ahci_qc_complete drivers/ata/libahci.c:1887 [inline] ahci_handle_port_interrupt+0x3d5/0x610 drivers/ata/libahci.c:1954 ahci_port_intr drivers/ata/libahci.c:1965 [inline] ahci_handle_port_intr+0x19f/0x2e0 drivers/ata/libahci.c:1996 ahci_single_level_irq_intr+0x9b/0xe0 drivers/ata/libahci.c:2030 __handle_irq_event_percpu+0x295/0xab0 kernel/irq/handle.c:203 handle_irq_event_percpu kernel/irq/handle.c:240 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:257 handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:254 [inline] call_irq_handler arch/x86/kernel/irq.c:-1 [inline] __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:325 common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:318 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4946 [inline] slab_alloc_node mm/slub.c:5245 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5252 mempool_alloc_noprof+0x1a4/0x510 mm/mempool.c:406 __sg_alloc_table+0x1b9/0x700 lib/scatterlist.c:299 sg_alloc_table_chained+0x85/0x1e0 lib/sg_pool.c:133 scsi_alloc_sgtables+0x291/0xc40 drivers/scsi/scsi_lib.c:1143 sd_setup_read_write_cmnd drivers/scsi/sd.c:1336 [inline] sd_init_command+0x558/0x1ff0 drivers/scsi/sd.c:1458 scsi_prepare_cmd drivers/scsi/scsi_lib.c:1708 [inline] scsi_queue_rq+0x176e/0x2cc0 drivers/scsi/scsi_lib.c:1849 blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2129 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x404/0x4f0 block/blk-mq.c:2367 blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1 blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2976 __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1225 blk_finish_plug+0x5e/0x90 block/blk-core.c:1252 wb_writeback+0xa80/0xaf0 fs/fs-writeback.c:2233 wb_check_old_data_flush fs/fs-writeback.c:2301 [inline] wb_do_writeback fs/fs-writeback.c:2354 [inline] wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2382 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 to a HARDIRQ-irq-unsafe lock: (&p->sequence){+.-.}-{0:0} ... which became HARDIRQ-irq-unsafe at: ... lock_acquire+0x120/0x360 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+0x1a3/0x3a0 lib/flex_proportions.c:74 writeout_period+0x8b/0x130 mm/page-writeback.c:615 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0x103/0x180 kernel/time/timer.c:2404 handle_softirqs+0x283/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3ae/0x410 init/main.c:1111 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 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#12); lock(&p->sequence); lock(&xa->xa_lock#12); *** DEADLOCK *** 4 locks held by syz.0.0/5341: #0: ffff88801af3a420 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88801f374148 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:979 [inline] #1: ffff88801f374148 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: fuse_open+0x283/0x750 fs/fuse/file.c:253 #2: ffff88801f374638 (&fi->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff88801f374638 (&fi->lock){+.+.}-{3:3}, at: fuse_release_nowrite+0x2f/0xd0 fs/fuse/dir.c:1875 #3: ffff88801f374240 (&xa->xa_lock#12){-...}-{3:3}, at: __folio_end_writeback+0x1da/0x950 mm/page-writeback.c:2996 the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&xa->xa_lock#12){-...}-{3:3} { IN-HARDIRQ-W at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 __folio_end_writeback+0x1da/0x950 mm/page-writeback.c:2996 folio_end_writeback_no_dropbehind+0x151/0x290 mm/filemap.c:1668 folio_end_writeback+0xea/0x220 mm/filemap.c:1694 end_bio_bh_io_sync+0xbd/0x120 fs/buffer.c:2776 blk_update_request+0x57e/0xe60 block/blk-mq.c:998 scsi_end_request+0x7c/0x830 drivers/scsi/scsi_lib.c:637 scsi_io_completion+0x131/0x390 drivers/scsi/scsi_lib.c:1078 ata_qc_complete_multiple+0x1ae/0x280 drivers/ata/libata-sata.c:789 ahci_qc_complete drivers/ata/libahci.c:1887 [inline] ahci_handle_port_interrupt+0x3d5/0x610 drivers/ata/libahci.c:1954 ahci_port_intr drivers/ata/libahci.c:1965 [inline] ahci_handle_port_intr+0x19f/0x2e0 drivers/ata/libahci.c:1996 ahci_single_level_irq_intr+0x9b/0xe0 drivers/ata/libahci.c:2030 __handle_irq_event_percpu+0x295/0xab0 kernel/irq/handle.c:203 handle_irq_event_percpu kernel/irq/handle.c:240 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:257 handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:254 [inline] call_irq_handler arch/x86/kernel/irq.c:-1 [inline] __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:325 common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:318 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4946 [inline] slab_alloc_node mm/slub.c:5245 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5252 mempool_alloc_noprof+0x1a4/0x510 mm/mempool.c:406 __sg_alloc_table+0x1b9/0x700 lib/scatterlist.c:299 sg_alloc_table_chained+0x85/0x1e0 lib/sg_pool.c:133 scsi_alloc_sgtables+0x291/0xc40 drivers/scsi/scsi_lib.c:1143 sd_setup_read_write_cmnd drivers/scsi/sd.c:1336 [inline] sd_init_command+0x558/0x1ff0 drivers/scsi/sd.c:1458 scsi_prepare_cmd drivers/scsi/scsi_lib.c:1708 [inline] scsi_queue_rq+0x176e/0x2cc0 drivers/scsi/scsi_lib.c:1849 blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2129 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x404/0x4f0 block/blk-mq.c:2367 blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1 blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2976 __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1225 blk_finish_plug+0x5e/0x90 block/blk-core.c:1252 wb_writeback+0xa80/0xaf0 fs/fs-writeback.c:2233 wb_check_old_data_flush fs/fs-writeback.c:2301 [inline] wb_do_writeback fs/fs-writeback.c:2354 [inline] wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2382 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INITIAL USE at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] shmem_add_to_page_cache+0x72d/0xba0 mm/shmem.c:887 shmem_alloc_and_add_folio+0x846/0xf60 mm/shmem.c:1936 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2533 shmem_read_folio_gfp+0x8a/0xe0 mm/shmem.c:5931 drm_gem_get_pages+0x223/0xa20 drivers/gpu/drm/drm_gem.c:656 drm_gem_shmem_get_pages_locked+0x201/0x440 drivers/gpu/drm/drm_gem_shmem_helper.c:200 drm_gem_shmem_pin_locked+0x22c/0x460 drivers/gpu/drm/drm_gem_shmem_helper.c:261 drm_gem_shmem_vmap_locked+0x46b/0x790 drivers/gpu/drm/drm_gem_shmem_helper.c:365 drm_gem_vmap_locked drivers/gpu/drm/drm_gem.c:1279 [inline] drm_gem_vmap+0x10a/0x1d0 drivers/gpu/drm/drm_gem.c:1321 drm_client_buffer_vmap+0x43/0x80 drivers/gpu/drm/drm_client.c:312 drm_fbdev_shmem_driver_fbdev_probe+0x258/0x900 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+0x1236/0x18a0 drivers/gpu/drm/drm_fb_helper.c:1830 drm_fbdev_client_hotplug+0x16c/0x230 drivers/gpu/drm/clients/drm_fbdev_client.c:52 drm_client_register+0x172/0x210 drivers/gpu/drm/drm_client.c:141 drm_fbdev_client_setup+0x19f/0x3f0 drivers/gpu/drm/clients/drm_fbdev_client.c:159 drm_client_setup+0x107/0x220 drivers/gpu/drm/clients/drm_client_setup.c:46 vkms_create drivers/gpu/drm/vkms/vkms_drv.c:201 [inline] vkms_init+0x3e0/0x4b0 drivers/gpu/drm/vkms/vkms_drv.c:221 do_one_initcall+0x233/0x820 init/main.c:1283 do_initcall_level+0x104/0x190 init/main.c:1345 do_initcalls+0x59/0xa0 init/main.c:1361 kernel_init_freeable+0x334/0x4b0 init/main.c:1593 kernel_init+0x1d/0x1d0 init/main.c:1483 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 } ... key at: [] 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+0x120/0x360 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+0x1a3/0x3a0 lib/flex_proportions.c:74 writeout_period+0x8b/0x130 mm/page-writeback.c:615 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0x103/0x180 kernel/time/timer.c:2404 handle_softirqs+0x283/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3ae/0x410 init/main.c:1111 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 IN-SOFTIRQ-W at: lock_acquire+0x120/0x360 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+0x1a3/0x3a0 lib/flex_proportions.c:74 writeout_period+0x8b/0x130 mm/page-writeback.c:615 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0x103/0x180 kernel/time/timer.c:2404 handle_softirqs+0x283/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3ae/0x410 init/main.c:1111 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 USE at: lock_acquire+0x120/0x360 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+0x1a3/0x3a0 lib/flex_proportions.c:74 writeout_period+0x8b/0x130 mm/page-writeback.c:615 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0x103/0x180 kernel/time/timer.c:2404 handle_softirqs+0x283/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3ae/0x410 init/main.c:1111 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+0x120/0x360 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline] fprop_fraction_percpu+0x170/0x400 lib/flex_proportions.c:155 __wb_calc_thresh+0x119/0x4a0 mm/page-writeback.c:913 wb_bg_dirty_limits mm/page-writeback.c:2130 [inline] domain_over_bg_thresh mm/page-writeback.c:2144 [inline] wb_over_bg_thresh+0x154/0x3d0 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+0xb1c/0xef0 fs/fs-writeback.c:2382 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 } ... key at: [] fprop_global_init.__key.1+0x0/0x20 ... acquired at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline] fprop_fraction_percpu+0x130/0x400 lib/flex_proportions.c:155 __fprop_add_percpu_max+0x10d/0x210 lib/flex_proportions.c:186 wb_domain_writeout_add mm/page-writeback.c:562 [inline] __wb_writeout_add+0xa5/0x290 mm/page-writeback.c:586 __folio_end_writeback+0x4d5/0x950 mm/page-writeback.c:3003 folio_end_writeback_no_dropbehind+0x151/0x290 mm/filemap.c:1668 folio_end_writeback+0xea/0x220 mm/filemap.c:1694 fuse_writepage_finish fs/fuse/file.c:1837 [inline] fuse_send_writepage fs/fuse/file.c:1887 [inline] fuse_flush_writepages+0x6c8/0x900 fs/fuse/file.c:1912 __fuse_release_nowrite fs/fuse/dir.c:1868 [inline] fuse_release_nowrite+0x7b/0xd0 fs/fuse/dir.c:1876 fuse_open+0x4c4/0x750 fs/fuse/file.c:276 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4134 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_creat fs/open.c:1530 [inline] __se_sys_creat fs/open.c:1524 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1524 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f stack backtrace: CPU: 0 UID: 0 PID: 5341 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: dump_stack_lvl+0x189/0x250 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+0x1f05/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline] fprop_fraction_percpu+0x130/0x400 lib/flex_proportions.c:155 __fprop_add_percpu_max+0x10d/0x210 lib/flex_proportions.c:186 wb_domain_writeout_add mm/page-writeback.c:562 [inline] __wb_writeout_add+0xa5/0x290 mm/page-writeback.c:586 __folio_end_writeback+0x4d5/0x950 mm/page-writeback.c:3003 folio_end_writeback_no_dropbehind+0x151/0x290 mm/filemap.c:1668 folio_end_writeback+0xea/0x220 mm/filemap.c:1694 fuse_writepage_finish fs/fuse/file.c:1837 [inline] fuse_send_writepage fs/fuse/file.c:1887 [inline] fuse_flush_writepages+0x6c8/0x900 fs/fuse/file.c:1912 __fuse_release_nowrite fs/fuse/dir.c:1868 [inline] fuse_release_nowrite+0x7b/0xd0 fs/fuse/dir.c:1876 fuse_open+0x4c4/0x750 fs/fuse/file.c:276 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4134 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_creat fs/open.c:1530 [inline] __se_sys_creat fs/open.c:1524 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1524 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f372158eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f37224fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f37217e5fa0 RCX: 00007f372158eec9 RDX: 0000000000000000 RSI: 0000000000000034 RDI: 0000200000000140 RBP: 00007f3721611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f37217e6038 R14: 00007f37217e5fa0 R15: 00007ffc65500018