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List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6602:2d81:b0:8e3:2d3d:9a7d with SMTP id ca18e2360f4ac-93bd19a9a40mr98350239f.18.1759871969687; Tue, 07 Oct 2025 14:19:29 -0700 (PDT) Date: Tue, 07 Oct 2025 14:19:29 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68e583e1.a00a0220.298cc0.0485.GAE@google.com> Subject: [syzbot] [fuse?] possible deadlock in __folio_end_writeback From: syzbot To: akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, miklos@szeredi.hu, syzkaller-bugs@googlegroups.com, willy@infradead.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: cbf33b8e0b36 Merge tag 'bpf-fixes' of git://git.kernel.org.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17a25ee2580000 kernel config: https://syzkaller.appspot.com/x/.config?x=1b4263e12240e6e1 dashboard link: https://syzkaller.appspot.com/bug?extid=27727256237e6bdd3649 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14eaea7c580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=134c4304580000 Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-cbf33b8e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/54786e46ef23/vmlinux-cbf33b8e.xz kernel image: https://storage.googleapis.com/syzbot-assets/dd6f88ce083b/bzImage-cbf33b8e.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+27727256237e6bdd3649@syzkaller.appspotmail.com wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 ===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected syzkaller #0 Not tainted ----------------------------------------------------- kworker/u4:0/12 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffffffff995aa110 (&p->sequence){+.-.}-{0:0}, at: __fprop_add_percpu_max+0x10d/0x210 lib/flex_proportions.c:186 and this task is already holding: ffff888040a24240 (&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+0xba/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 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] ata_scsi_queuecmd+0x3f0/0x5c0 drivers/ata/libata-scsi.c:4398 scsi_dispatch_cmd drivers/scsi/scsi_lib.c:1626 [inline] scsi_queue_rq+0x1c91/0x2cc0 drivers/scsi/scsi_lib.c:1868 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+0x436/0x7d0 arch/x86/kernel/process.c:148 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+0x17e/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 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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 *** 5 locks held by kworker/u4:0/12: #0: ffff888030f92948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff888030f92948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900001e7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900001e7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff888000a240e0 (&type->s_umount_key#54){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff888040a24638 (&fi->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff888040a24638 (&fi->lock){+.+.}-{3:3}, at: fuse_writepages_send fs/fuse/file.c:2089 [inline] #3: ffff888040a24638 (&fi->lock){+.+.}-{3:3}, at: fuse_iomap_writeback_range+0x818/0x1800 fs/fuse/file.c:2150 #4: ffff888040a24240 (&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+0xba/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 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] ata_scsi_queuecmd+0x3f0/0x5c0 drivers/ata/libata-scsi.c:4398 scsi_dispatch_cmd drivers/scsi/scsi_lib.c:1626 [inline] scsi_queue_rq+0x1c91/0x2cc0 drivers/scsi/scsi_lib.c:1868 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+0x436/0x7d0 arch/x86/kernel/process.c:148 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+0x436/0x7d0 arch/x86/kernel/process.c:148 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+0x17e/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 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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+0x17e/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 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 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 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+0x17e/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 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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+0x436/0x7d0 arch/x86/kernel/process.c:148 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_writepages_send fs/fuse/file.c:2091 [inline] fuse_iomap_writeback_range+0x923/0x1800 fs/fuse/file.c:2150 iomap_writeback_range fs/iomap/buffered-io.c:1593 [inline] iomap_writeback_folio+0xe72/0x1c80 fs/iomap/buffered-io.c:1718 iomap_writepages+0x162/0x2d0 fs/iomap/buffered-io.c:1770 fuse_writepages+0x2ad/0x380 fs/fuse/file.c:2220 do_writepages+0x32b/0x550 mm/page-writeback.c:2604 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:2015 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2086 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2197 wb_check_background_flush fs/fs-writeback.c:2267 [inline] wb_do_writeback fs/fs-writeback.c:2355 [inline] wb_workfn+0xb63/0xef0 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+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 stack backtrace: CPU: 0 UID: 0 PID: 12 Comm: kworker/u4:0 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 Workqueue: writeback wb_workfn (flush-0:42) 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_writepages_send fs/fuse/file.c:2091 [inline] fuse_iomap_writeback_range+0x923/0x1800 fs/fuse/file.c:2150 iomap_writeback_range fs/iomap/buffered-io.c:1593 [inline] iomap_writeback_folio+0xe72/0x1c80 fs/iomap/buffered-io.c:1718 iomap_writepages+0x162/0x2d0 fs/iomap/buffered-io.c:1770 fuse_writepages+0x2ad/0x380 fs/fuse/file.c:2220 do_writepages+0x32b/0x550 mm/page-writeback.c:2604 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:2015 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2086 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2197 wb_check_background_flush fs/fs-writeback.c:2267 [inline] wb_do_writeback fs/fs-writeback.c:2355 [inline] wb_workfn+0xb63/0xef0 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+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 --- This report is generated by a bot. 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