===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected syzkaller #0 Not tainted ----------------------------------------------------- syz.3.56/6932 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffff8000973c1dd0 (&p->sequence){+.-.}-{0:0}, at: __fprop_add_percpu_max+0x130/0x1f4 lib/flex_proportions.c:186 and this task is already holding: ffff0000f31e8240 (&xa->xa_lock#10){-.-.}-{3:3}, at: __folio_end_writeback+0x10c/0x75c mm/page-writeback.c:2996 which would create a new lock dependency: (&xa->xa_lock#10){-.-.}-{3:3} -> (&p->sequence){+.-.}-{0:0} but this new dependency connects a HARDIRQ-irq-safe lock: (&xa->xa_lock#10){-.-.}-{3:3} ... which became HARDIRQ-irq-safe at: lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x5c/0x7c kernel/locking/spinlock.c:162 __folio_end_writeback+0x10c/0x75c mm/page-writeback.c:2996 folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1668 folio_end_writeback+0xd8/0x248 mm/filemap.c:1694 end_buffer_async_write+0x20c/0x350 fs/buffer.c:419 end_bio_bh_io_sync+0xb0/0x184 fs/buffer.c:2776 bio_endio+0x858/0x894 block/bio.c:1672 blk_complete_request block/blk-mq.c:899 [inline] blk_mq_end_request_batch+0x49c/0x105c block/blk-mq.c:1193 nvme_complete_batch drivers/nvme/host/nvme.h:795 [inline] nvme_pci_complete_batch drivers/nvme/host/pci.c:1277 [inline] nvme_irq+0x1ec/0x240 drivers/nvme/host/pci.c:1379 __handle_irq_event_percpu+0x224/0x8e4 kernel/irq/handle.c:203 handle_irq_event_percpu kernel/irq/handle.c:240 [inline] handle_irq_event+0x9c/0x1d0 kernel/irq/handle.c:257 handle_fasteoi_irq+0x328/0x8d8 kernel/irq/chip.c:764 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq_desc kernel/irq/irqdesc.c:669 [inline] generic_handle_domain_irq+0xe0/0x140 kernel/irq/irqdesc.c:725 __gic_handle_irq drivers/irqchip/irq-gic-v3.c:874 [inline] __gic_handle_irq_from_irqson drivers/irqchip/irq-gic-v3.c:925 [inline] gic_handle_irq+0x6c/0x190 drivers/irqchip/irq-gic-v3.c:969 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_interrupt_handler+0xd4/0x138 arch/arm64/kernel/entry-common.c: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 __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline] arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] _raw_spin_unlock_irqrestore+0x44/0x98 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __uart_port_unlock_irqrestore include/linux/serial_core.h:616 [inline] pl011_console_device_unlock+0x90/0xc8 drivers/tty/serial/amba-pl011.c:2603 nbcon_emit_one kernel/printk/nbcon.c:1142 [inline] nbcon_kthread_func+0x58c/0x6d0 kernel/printk/nbcon.c:1229 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 to a HARDIRQ-irq-unsafe lock: (&p->sequence){+.-.}-{0:0} ... which became HARDIRQ-irq-unsafe at: ... lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868 do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline] do_write_seqcount_begin include/linux/seqlock.h:503 [inline] fprop_new_period+0x3b8/0x718 lib/flex_proportions.c:74 writeout_period+0x94/0x11c mm/page-writeback.c:615 call_timer_fn+0x1b4/0x818 kernel/time/timer.c: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+0x328/0xc88 kernel/softirq.c:622 __do_softirq+0x14/0x20 kernel/softirq.c:656 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:68 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:73 invoke_softirq kernel/softirq.c:503 [inline] __irq_exit_rcu+0x1b0/0x478 kernel/softirq.c:723 irq_exit_rcu+0x14/0x84 kernel/softirq.c:739 __el1_irq arch/arm64/kernel/entry-common.c: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_restore arch/arm64/include/asm/irqflags.h:175 [inline] arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] lock_release+0x270/0x39c kernel/locking/lockdep.c:5892 fs_reclaim_acquire+0xd0/0x118 mm/page_alloc.c:4282 might_alloc include/linux/sched/mm.h:318 [inline] slab_pre_alloc_hook mm/slub.c:4929 [inline] slab_alloc_node mm/slub.c:5264 [inline] __do_kmalloc_node mm/slub.c:5649 [inline] __kmalloc_noprof+0xcc/0x728 mm/slub.c:5662 kmalloc_noprof include/linux/slab.h:961 [inline] tomoyo_realpath_from_path+0xc4/0x4d4 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x178/0x31c security/tomoyo/file.c:771 tomoyo_file_open+0x154/0x1ec security/tomoyo/tomoyo.c:334 security_file_open+0xc8/0x298 security/security.c:3183 do_dentry_open+0x2a0/0x10bc fs/open.c:942 vfs_open+0x44/0x2d4 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2424/0x2c40 fs/namei.c:4134 do_filp_open+0x18c/0x36c fs/namei.c:4161 do_sys_openat2+0x11c/0x1b4 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __arm64_sys_openat+0x120/0x158 fs/open.c:1463 __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/0x254 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 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->sequence); local_irq_disable(); lock(&xa->xa_lock#10); lock(&p->sequence); lock(&xa->xa_lock#10); *** DEADLOCK *** 5 locks held by syz.3.56/6932: #0: ffff0000d5a702b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x1fc/0x2a0 fs/file.c:1232 #1: ffff0000d75f0420 (sb_writers#19){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3113 [inline] #1: ffff0000d75f0420 (sb_writers#19){.+.+}-{0:0}, at: vfs_writev+0x21c/0x7cc fs/read_write.c:1055 #2: ffff0000f31e8148 (&sb->s_type->i_mutex_key#25){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #2: ffff0000f31e8148 (&sb->s_type->i_mutex_key#25){+.+.}-{4:4}, at: fuse_fsync+0xf0/0x2b8 fs/fuse/file.c:528 #3: ffff0000f31e8638 (&fi->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff0000f31e8638 (&fi->lock){+.+.}-{3:3}, at: fuse_writepages_send fs/fuse/file.c:2089 [inline] #3: ffff0000f31e8638 (&fi->lock){+.+.}-{3:3}, at: fuse_iomap_writeback_submit+0xd4/0x220 fs/fuse/file.c:2185 #4: ffff0000f31e8240 (&xa->xa_lock#10){-.-.}-{3:3}, at: __folio_end_writeback+0x10c/0x75c mm/page-writeback.c:2996 the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&xa->xa_lock#10){-.-.}-{3:3} { IN-HARDIRQ-W at: lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x5c/0x7c kernel/locking/spinlock.c:162 __folio_end_writeback+0x10c/0x75c mm/page-writeback.c:2996 folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1668 folio_end_writeback+0xd8/0x248 mm/filemap.c:1694 end_buffer_async_write+0x20c/0x350 fs/buffer.c:419 end_bio_bh_io_sync+0xb0/0x184 fs/buffer.c:2776 bio_endio+0x858/0x894 block/bio.c:1672 blk_complete_request block/blk-mq.c:899 [inline] blk_mq_end_request_batch+0x49c/0x105c block/blk-mq.c:1193 nvme_complete_batch drivers/nvme/host/nvme.h:795 [inline] nvme_pci_complete_batch drivers/nvme/host/pci.c:1277 [inline] nvme_irq+0x1ec/0x240 drivers/nvme/host/pci.c:1379 __handle_irq_event_percpu+0x224/0x8e4 kernel/irq/handle.c:203 handle_irq_event_percpu kernel/irq/handle.c:240 [inline] handle_irq_event+0x9c/0x1d0 kernel/irq/handle.c:257 handle_fasteoi_irq+0x328/0x8d8 kernel/irq/chip.c:764 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq_desc kernel/irq/irqdesc.c:669 [inline] generic_handle_domain_irq+0xe0/0x140 kernel/irq/irqdesc.c:725 __gic_handle_irq drivers/irqchip/irq-gic-v3.c:874 [inline] __gic_handle_irq_from_irqson drivers/irqchip/irq-gic-v3.c:925 [inline] gic_handle_irq+0x6c/0x190 drivers/irqchip/irq-gic-v3.c:969 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_interrupt_handler+0xd4/0x138 arch/arm64/kernel/entry-common.c: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 __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline] arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] _raw_spin_unlock_irqrestore+0x44/0x98 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __uart_port_unlock_irqrestore include/linux/serial_core.h:616 [inline] pl011_console_device_unlock+0x90/0xc8 drivers/tty/serial/amba-pl011.c:2603 nbcon_emit_one kernel/printk/nbcon.c:1142 [inline] nbcon_kthread_func+0x58c/0x6d0 kernel/printk/nbcon.c:1229 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 IN-SOFTIRQ-W at: lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x5c/0x7c kernel/locking/spinlock.c:162 __folio_end_writeback+0x10c/0x75c mm/page-writeback.c:2996 folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1668 folio_end_writeback+0xd8/0x248 mm/filemap.c:1694 ext4_finish_bio+0x570/0x8a4 fs/ext4/page-io.c:144 ext4_end_bio+0x378/0x624 fs/ext4/page-io.c:-1 bio_endio+0x858/0x894 block/bio.c:1672 blk_update_request+0x474/0xba8 block/blk-mq.c:998 blk_mq_end_request+0x54/0x88 block/blk-mq.c:1160 lo_complete_rq+0x124/0x274 drivers/block/loop.c:314 blk_complete_reqs block/blk-mq.c:1235 [inline] blk_done_softirq+0x11c/0x168 block/blk-mq.c:1240 handle_softirqs+0x328/0xc88 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+0x14c/0x2e0 kernel/locking/lockdep.c:5868 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x58/0x70 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] shmem_add_to_page_cache+0x564/0xa24 mm/shmem.c:886 shmem_alloc_and_add_folio+0x758/0x10c4 mm/shmem.c:1938 shmem_get_folio_gfp+0x4d4/0x159c mm/shmem.c:2535 shmem_read_folio_gfp+0x8c/0xf0 mm/shmem.c:5933 drm_gem_get_pages+0x1cc/0x7c0 drivers/gpu/drm/drm_gem.c:656 drm_gem_shmem_get_pages_locked+0x1d4/0x364 drivers/gpu/drm/drm_gem_shmem_helper.c:200 drm_gem_shmem_pin_locked+0x1f8/0x410 drivers/gpu/drm/drm_gem_shmem_helper.c:261 drm_gem_shmem_vmap_locked+0x3cc/0x658 drivers/gpu/drm/drm_gem_shmem_helper.c:365 drm_gem_shmem_object_vmap+0x28/0x38 include/drm/drm_gem_shmem_helper.h:243 drm_gem_vmap_locked drivers/gpu/drm/drm_gem.c:1279 [inline] drm_gem_vmap+0x104/0x1d8 drivers/gpu/drm/drm_gem.c:1321 drm_client_buffer_vmap+0x48/0x90 drivers/gpu/drm/drm_client.c:312 drm_fbdev_shmem_driver_fbdev_probe+0x1d8/0x70c drivers/gpu/drm/drm_fbdev_shmem.c:160 drm_fb_helper_single_fb_probe drivers/gpu/drm/drm_fb_helper.c:1650 [inline] __drm_fb_helper_initial_config_and_unlock+0xf94/0x159c drivers/gpu/drm/drm_fb_helper.c:1830 drm_fb_helper_initial_config+0x3c/0x58 drivers/gpu/drm/drm_fb_helper.c:1917 drm_fbdev_client_hotplug+0x154/0x22c drivers/gpu/drm/clients/drm_fbdev_client.c:52 drm_client_register+0x13c/0x1d4 drivers/gpu/drm/drm_client.c:141 drm_fbdev_client_setup+0x194/0x3d0 drivers/gpu/drm/clients/drm_fbdev_client.c:159 drm_client_setup+0x114/0x228 drivers/gpu/drm/clients/drm_client_setup.c:46 vkms_create drivers/gpu/drm/vkms/vkms_drv.c:201 [inline] vkms_init+0x338/0x3f0 drivers/gpu/drm/vkms/vkms_drv.c:221 do_one_initcall+0x250/0x990 init/main.c:1283 do_initcall_level+0x128/0x1c4 init/main.c:1345 do_initcalls+0x70/0xd0 init/main.c:1361 do_basic_setup+0x78/0x8c init/main.c:1380 kernel_init_freeable+0x268/0x39c init/main.c:1593 kernel_init+0x24/0x1dc init/main.c:1483 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 } ... key at: [] xa_init_flags.__key+0x0/0x20 the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (&p->sequence){+.-.}-{0:0} { HARDIRQ-ON-W at: lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868 do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline] do_write_seqcount_begin include/linux/seqlock.h:503 [inline] fprop_new_period+0x3b8/0x718 lib/flex_proportions.c:74 writeout_period+0x94/0x11c mm/page-writeback.c:615 call_timer_fn+0x1b4/0x818 kernel/time/timer.c: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+0x328/0xc88 kernel/softirq.c:622 __do_softirq+0x14/0x20 kernel/softirq.c:656 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:68 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:73 invoke_softirq kernel/softirq.c:503 [inline] __irq_exit_rcu+0x1b0/0x478 kernel/softirq.c:723 irq_exit_rcu+0x14/0x84 kernel/softirq.c:739 __el1_irq arch/arm64/kernel/entry-common.c: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_restore arch/arm64/include/asm/irqflags.h:175 [inline] arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] lock_release+0x270/0x39c kernel/locking/lockdep.c:5892 fs_reclaim_acquire+0xd0/0x118 mm/page_alloc.c:4282 might_alloc include/linux/sched/mm.h:318 [inline] slab_pre_alloc_hook mm/slub.c:4929 [inline] slab_alloc_node mm/slub.c:5264 [inline] __do_kmalloc_node mm/slub.c:5649 [inline] __kmalloc_noprof+0xcc/0x728 mm/slub.c:5662 kmalloc_noprof include/linux/slab.h:961 [inline] tomoyo_realpath_from_path+0xc4/0x4d4 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x178/0x31c security/tomoyo/file.c:771 tomoyo_file_open+0x154/0x1ec security/tomoyo/tomoyo.c:334 security_file_open+0xc8/0x298 security/security.c:3183 do_dentry_open+0x2a0/0x10bc fs/open.c:942 vfs_open+0x44/0x2d4 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2424/0x2c40 fs/namei.c:4134 do_filp_open+0x18c/0x36c fs/namei.c:4161 do_sys_openat2+0x11c/0x1b4 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __arm64_sys_openat+0x120/0x158 fs/open.c:1463 __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/0x254 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+0x14c/0x2e0 kernel/locking/lockdep.c:5868 do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline] do_write_seqcount_begin include/linux/seqlock.h:503 [inline] fprop_new_period+0x3b8/0x718 lib/flex_proportions.c:74 writeout_period+0x94/0x11c mm/page-writeback.c:615 call_timer_fn+0x1b4/0x818 kernel/time/timer.c: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+0x328/0xc88 kernel/softirq.c:622 __do_softirq+0x14/0x20 kernel/softirq.c:656 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:68 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:73 invoke_softirq kernel/softirq.c:503 [inline] __irq_exit_rcu+0x1b0/0x478 kernel/softirq.c:723 irq_exit_rcu+0x14/0x84 kernel/softirq.c:739 __el1_irq arch/arm64/kernel/entry-common.c: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_restore arch/arm64/include/asm/irqflags.h:175 [inline] arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] lock_release+0x270/0x39c kernel/locking/lockdep.c:5892 fs_reclaim_acquire+0xd0/0x118 mm/page_alloc.c:4282 might_alloc include/linux/sched/mm.h:318 [inline] slab_pre_alloc_hook mm/slub.c:4929 [inline] slab_alloc_node mm/slub.c:5264 [inline] __do_kmalloc_node mm/slub.c:5649 [inline] __kmalloc_noprof+0xcc/0x728 mm/slub.c:5662 kmalloc_noprof include/linux/slab.h:961 [inline] tomoyo_realpath_from_path+0xc4/0x4d4 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x178/0x31c security/tomoyo/file.c:771 tomoyo_file_open+0x154/0x1ec security/tomoyo/tomoyo.c:334 security_file_open+0xc8/0x298 security/security.c:3183 do_dentry_open+0x2a0/0x10bc fs/open.c:942 vfs_open+0x44/0x2d4 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2424/0x2c40 fs/namei.c:4134 do_filp_open+0x18c/0x36c fs/namei.c:4161 do_sys_openat2+0x11c/0x1b4 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __arm64_sys_openat+0x120/0x158 fs/open.c:1463 __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/0x254 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 INITIAL USE at: lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868 do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline] do_write_seqcount_begin include/linux/seqlock.h:503 [inline] fprop_new_period+0x3b8/0x718 lib/flex_proportions.c:74 writeout_period+0x94/0x11c mm/page-writeback.c:615 call_timer_fn+0x1b4/0x818 kernel/time/timer.c: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+0x328/0xc88 kernel/softirq.c:622 __do_softirq+0x14/0x20 kernel/softirq.c:656 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:68 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:891 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:73 invoke_softirq kernel/softirq.c:503 [inline] __irq_exit_rcu+0x1b0/0x478 kernel/softirq.c:723 irq_exit_rcu+0x14/0x84 kernel/softirq.c:739 __el1_irq arch/arm64/kernel/entry-common.c: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_restore arch/arm64/include/asm/irqflags.h:175 [inline] arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] lock_release+0x270/0x39c kernel/locking/lockdep.c:5892 fs_reclaim_acquire+0xd0/0x118 mm/page_alloc.c:4282 might_alloc include/linux/sched/mm.h:318 [inline] slab_pre_alloc_hook mm/slub.c:4929 [inline] slab_alloc_node mm/slub.c:5264 [inline] __do_kmalloc_node mm/slub.c:5649 [inline] __kmalloc_noprof+0xcc/0x728 mm/slub.c:5662 kmalloc_noprof include/linux/slab.h:961 [inline] tomoyo_realpath_from_path+0xc4/0x4d4 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x178/0x31c security/tomoyo/file.c:771 tomoyo_file_open+0x154/0x1ec security/tomoyo/tomoyo.c:334 security_file_open+0xc8/0x298 security/security.c:3183 do_dentry_open+0x2a0/0x10bc fs/open.c:942 vfs_open+0x44/0x2d4 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2424/0x2c40 fs/namei.c:4134 do_filp_open+0x18c/0x36c fs/namei.c:4161 do_sys_openat2+0x11c/0x1b4 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __arm64_sys_openat+0x120/0x158 fs/open.c:1463 __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/0x254 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 INITIAL READ USE at: lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline] fprop_fraction_percpu+0xac/0x270 lib/flex_proportions.c:155 __wb_calc_thresh+0xfc/0x3b0 mm/page-writeback.c:913 wb_bg_dirty_limits mm/page-writeback.c:2130 [inline] domain_over_bg_thresh+0xb8/0x1f0 mm/page-writeback.c:2144 wb_over_bg_thresh+0xf8/0x17c mm/page-writeback.c:2165 wb_check_background_flush fs/fs-writeback.c:2257 [inline] wb_do_writeback fs/fs-writeback.c:2355 [inline] wb_workfn+0xa30/0xdc0 fs/fs-writeback.c:2382 process_one_work+0x7e8/0x155c kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3427 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 } ... key at: [] fprop_global_init.__key.1+0x0/0x20 ... acquired at: seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline] fprop_fraction_percpu+0xf0/0x270 lib/flex_proportions.c:155 __fprop_add_percpu_max+0x130/0x1f4 lib/flex_proportions.c:186 wb_domain_writeout_add mm/page-writeback.c:562 [inline] __wb_writeout_add+0xbc/0x27c mm/page-writeback.c:586 __folio_end_writeback+0x380/0x75c mm/page-writeback.c:3003 folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1668 folio_end_writeback+0xd8/0x248 mm/filemap.c:1694 iomap_finish_folio_write+0x1c0/0x2a4 fs/iomap/buffered-io.c:1582 fuse_writepage_finish fs/fuse/file.c:1837 [inline] fuse_send_writepage fs/fuse/file.c:1887 [inline] fuse_flush_writepages+0x54c/0x73c fs/fuse/file.c:1912 fuse_writepages_send fs/fuse/file.c:2091 [inline] fuse_iomap_writeback_submit+0x188/0x220 fs/fuse/file.c:2185 iomap_writepages+0x1dc/0x25c fs/iomap/buffered-io.c:1784 fuse_writepages+0x208/0x2bc fs/fuse/file.c:2220 do_writepages+0x270/0x468 mm/page-writeback.c:2604 filemap_fdatawrite_wbc mm/filemap.c:389 [inline] __filemap_fdatawrite_range mm/filemap.c:422 [inline] file_write_and_wait_range+0x1d0/0x2c4 mm/filemap.c:797 fuse_fsync+0x100/0x2b8 fs/fuse/file.c:535 vfs_fsync_range+0x160/0x19c 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+0xa20/0xb88 fs/fuse/file.c:1783 do_iter_readv_writev+0x4bc/0x720 fs/read_write.c:-1 vfs_writev+0x29c/0x7cc fs/read_write.c:1057 do_writev+0x128/0x290 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+0x80/0x94 fs/read_write.c:1168 __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/0x254 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: 0 UID: 0 PID: 6932 Comm: syz.3.56 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+0x14c/0x2e0 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline] fprop_fraction_percpu+0xf0/0x270 lib/flex_proportions.c:155 __fprop_add_percpu_max+0x130/0x1f4 lib/flex_proportions.c:186 wb_domain_writeout_add mm/page-writeback.c:562 [inline] __wb_writeout_add+0xbc/0x27c mm/page-writeback.c:586 __folio_end_writeback+0x380/0x75c mm/page-writeback.c:3003 folio_end_writeback_no_dropbehind+0xd0/0x204 mm/filemap.c:1668 folio_end_writeback+0xd8/0x248 mm/filemap.c:1694 iomap_finish_folio_write+0x1c0/0x2a4 fs/iomap/buffered-io.c:1582 fuse_writepage_finish fs/fuse/file.c:1837 [inline] fuse_send_writepage fs/fuse/file.c:1887 [inline] fuse_flush_writepages+0x54c/0x73c fs/fuse/file.c:1912 fuse_writepages_send fs/fuse/file.c:2091 [inline] fuse_iomap_writeback_submit+0x188/0x220 fs/fuse/file.c:2185 iomap_writepages+0x1dc/0x25c fs/iomap/buffered-io.c:1784 fuse_writepages+0x208/0x2bc fs/fuse/file.c:2220 do_writepages+0x270/0x468 mm/page-writeback.c:2604 filemap_fdatawrite_wbc mm/filemap.c:389 [inline] __filemap_fdatawrite_range mm/filemap.c:422 [inline] file_write_and_wait_range+0x1d0/0x2c4 mm/filemap.c:797 fuse_fsync+0x100/0x2b8 fs/fuse/file.c:535 vfs_fsync_range+0x160/0x19c 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+0xa20/0xb88 fs/fuse/file.c:1783 do_iter_readv_writev+0x4bc/0x720 fs/read_write.c:-1 vfs_writev+0x29c/0x7cc fs/read_write.c:1057 do_writev+0x128/0x290 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+0x80/0x94 fs/read_write.c:1168 __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/0x254 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