From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f77.google.com (mail-ot1-f77.google.com [209.85.210.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 302DC37A4AE for ; Mon, 9 Feb 2026 14:36:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770647795; cv=none; b=SkLQZF1ND32+oWZt6u4oojdBTS4V9QQA7Ou+T5+wR83ETzSY2qgUa7dF7wTKDLKHmYQARJuODaP2EzXXx1wlmS9zGDjwgW+dIXbhM27luBMVsE24xIQpCCO4Kddse7CjIPtIQG9ykRwo5kFeW21A5r8ybnhoifLM0+GJdp0qAto= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770647795; c=relaxed/simple; bh=UZnLH0h3kaSf6wIOP8U/qcFKwknQrIn/FGYwyQGaehg=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=tITlc/G8noERiP08GaF+flzGh95aSGEZ1bqErw9msub+RYNH70LmWqLLMRFDeszw7CI+82NWAKVadeZFlCGhACXkJ3Z8ShLOpQCOKt9nEHJLeG5Ld96RwpwISd9qKscSI2oUAz3gV9QXb+wC3h89+8njgJvZ/Yq6XO/UMYr9T8E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.210.77 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-ot1-f77.google.com with SMTP id 46e09a7af769-7cfcf550e23so4872487a34.2 for ; Mon, 09 Feb 2026 06:36:34 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770647794; x=1771252594; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=0lzC3FE5Gg9ui+AagGYjOf20jX4g13SU5kAdfyvpY9U=; b=ole7XzZruuDef+KICUJ/0OTafzIRKiiEega4keWJpNInKsDQ5JvK/Ty8YuyiKA/gSO b5iQp9CRRal0r6y4D5/itUhCQv/JutHGaCrwQRw66QGB2I6wRMsEFr5RVN/c5+IIoXMF nc6NGclvikpJAU8p3hriRGn0oUAWt9C5MX9VZmnjQfyxaD1Tx1sSTFFokfgsFum4ljas z6KwL9kuVqKhDaSqgdZ/p5YtZ846WF8w3QxfBHgepvZXVRth+63iBlJx0VJNHu9qkG/g RqbE1PRebyVBFpoW8Uojj4rZxhl3OVX9IM7khYthWiRCwklLr+o0AmaYYE1u1wOgQHgF nhbg== X-Forwarded-Encrypted: i=1; AJvYcCXoHaBMP8ZTWSydheQ28nlwFXdcPLkCQtnhutwN8JjrqJb3ys/ECUZ/6bWnlkjW9iwotnFZbJdD+lVDSmE=@vger.kernel.org X-Gm-Message-State: AOJu0YxpptzuxKoOI4ivddD56tr57hfxLcWqVYK8z7SmrgcmZtJDEIW4 7RDFEVzSO+7hAMhSb1Zg1Hz9aS6W+48DLNrkSNgaJrpEz+W3qGmkdAUqbD3yYBtuH4RWpaDSv5R OEGgmvCLzx3vBXaapqGG551zgsJKh4ReVDQAX5RYM5iwg24BGiC3E4uNnfrk= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:6ae6:b0:663:888:73d1 with SMTP id 006d021491bc7-66d0c854006mr4808343eaf.60.1770647794068; Mon, 09 Feb 2026 06:36:34 -0800 (PST) Date: Mon, 09 Feb 2026 06:36:34 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6989f0f2.a00a0220.34fa92.0047.GAE@google.com> Subject: [syzbot] [fs?] [mm?] possible deadlock in writeout_period From: syzbot To: akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, willy@infradead.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 59e4d31a0470 Merge branches 'for-next/core' and 'for-next/.. git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci console output: https://syzkaller.appspot.com/x/log.txt?x=14454b22580000 kernel config: https://syzkaller.appspot.com/x/.config?x=8a8594efdc14f07a dashboard link: https://syzkaller.appspot.com/bug?extid=d38b792a5cbd941006fc compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 userspace arch: arm64 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/746a1d5c4188/disk-59e4d31a.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/2eefade79f10/vmlinux-59e4d31a.xz kernel image: https://storage.googleapis.com/syzbot-assets/140624ef24ed/Image-59e4d31a.gz.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d38b792a5cbd941006fc@syzkaller.appspotmail.com ======================================================== WARNING: possible irq lock inversion dependency detected syzkaller #0 Not tainted -------------------------------------------------------- syz-executor/6572 just changed the state of lock: ffff800097626150 (&p->sequence){+.-.}-{0:0}, at: writeout_period+0x94/0x11c mm/page-writeback.c:615 but this lock was taken by another, HARDIRQ-safe lock in the past: (&xa->xa_lock#10){-.-.}-{3:3} and interrupts could create inverse lock ordering between them. 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 *** 1 lock held by syz-executor/6572: #0: ffff800097bd7c40 ((&dom->period_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline] #0: ffff800097bd7c40 ((&dom->period_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd4/0x814 kernel/time/timer.c:1738 the shortest dependencies between 2nd lock and 1st lock: -> (&xa->xa_lock#10){-.-.}-{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 __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 end_buffer_async_write+0x20c/0x350 fs/buffer.c:419 end_bio_bh_io_sync+0xb0/0x184 fs/buffer.c:2776 bio_endio+0x8d4/0x910 block/bio.c:1675 blk_complete_request block/blk-mq.c:908 [inline] blk_mq_end_request_batch+0x49c/0x105c block/blk-mq.c:1202 nvme_complete_batch drivers/nvme/host/nvme.h:802 [inline] nvme_pci_complete_batch drivers/nvme/host/pci.c:1348 [inline] nvme_irq+0x1ec/0x240 drivers/nvme/host/pci.c:1450 __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 __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline] arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] kasan_quarantine_put+0xbc/0x1c8 mm/kasan/quarantine.c:234 __kasan_slab_free+0x8c/0xa4 mm/kasan/common.c:295 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free_after_rcu_debug+0x120/0x2f8 mm/slub.c:6729 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0x848/0x1774 kernel/rcu/tree.c:2857 rcu_core_si+0x10/0x1c kernel/rcu/tree.c:2874 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 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 end_buffer_async_write+0x20c/0x350 fs/buffer.c:419 end_bio_bh_io_sync+0xb0/0x184 fs/buffer.c:2776 bio_endio+0x8d4/0x910 block/bio.c:1675 blk_complete_request block/blk-mq.c:908 [inline] blk_mq_end_request_batch+0x49c/0x105c block/blk-mq.c:1202 nvme_complete_batch drivers/nvme/host/nvme.h:802 [inline] nvme_pci_complete_batch drivers/nvme/host/pci.c:1348 [inline] nvme_irq+0x1ec/0x240 drivers/nvme/host/pci.c:1450 __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 __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline] arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] kasan_quarantine_put+0xbc/0x1c8 mm/kasan/quarantine.c:234 __kasan_slab_free+0x8c/0xa4 mm/kasan/common.c:295 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free_after_rcu_debug+0x120/0x2f8 mm/slub.c:6729 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0x848/0x1774 kernel/rcu/tree.c:2857 rcu_core_si+0x10/0x1c kernel/rcu/tree.c:2874 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:5970 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:240 drm_gem_shmem_pin_locked+0x1f8/0x410 drivers/gpu/drm/drm_gem_shmem_helper.c:301 drm_gem_shmem_vmap_locked+0x3cc/0x658 drivers/gpu/drm/drm_gem_shmem_helper.c:405 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:1273 [inline] drm_gem_vmap+0x104/0x1d8 drivers/gpu/drm/drm_gem.c:1315 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: 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_close_sync+0x100/0x264 fs/file_table.c:573 __do_sys_close fs/open.c:1573 [inline] __se_sys_close fs/open.c:1558 [inline] __arm64_sys_close+0x7c/0x118 fs/open.c:1558 __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 -> (&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] preempt_schedule_irq+0x78/0x188 kernel/sched/core.c:7189 raw_irqentry_exit_cond_resched+0x30/0x44 kernel/entry/common.c:173 irqentry_exit+0x1b0/0x308 kernel/entry/common.c:216 exit_to_kernel_mode+0x10/0x1c arch/arm64/kernel/entry-common.c:58 __el1_irq arch/arm64/kernel/entry-common.c:500 [inline] el1_interrupt+0x4c/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] class_irqsave_destructor include/linux/irqflags.h:266 [inline] __free_object+0x514/0x720 lib/debugobjects.c:524 free_object lib/debugobjects.c:532 [inline] debug_object_free+0x298/0x3e4 lib/debugobjects.c:976 destroy_hrtimer_on_stack kernel/time/hrtimer.c:448 [inline] hrtimer_nanosleep+0x214/0x2a4 kernel/time/hrtimer.c:2178 common_nsleep+0xa0/0xb8 kernel/time/posix-timers.c:1352 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1398 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1375 [inline] __arm64_sys_clock_nanosleep+0x334/0x370 kernel/time/posix-timers.c:1375 __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 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] preempt_schedule_irq+0x78/0x188 kernel/sched/core.c:7189 raw_irqentry_exit_cond_resched+0x30/0x44 kernel/entry/common.c:173 irqentry_exit+0x1b0/0x308 kernel/entry/common.c:216 exit_to_kernel_mode+0x10/0x1c arch/arm64/kernel/entry-common.c:58 __el1_irq arch/arm64/kernel/entry-common.c:500 [inline] el1_interrupt+0x4c/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] class_irqsave_destructor include/linux/irqflags.h:266 [inline] __free_object+0x514/0x720 lib/debugobjects.c:524 free_object lib/debugobjects.c:532 [inline] debug_object_free+0x298/0x3e4 lib/debugobjects.c:976 destroy_hrtimer_on_stack kernel/time/hrtimer.c:448 [inline] hrtimer_nanosleep+0x214/0x2a4 kernel/time/hrtimer.c:2178 common_nsleep+0xa0/0xb8 kernel/time/posix-timers.c:1352 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1398 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1375 [inline] __arm64_sys_clock_nanosleep+0x334/0x370 kernel/time/posix-timers.c:1375 __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 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: mark_lock+0x170/0x1d0 kernel/locking/lockdep.c:4753 mark_usage kernel/locking/lockdep.c:4662 [inline] __lock_acquire+0x9a0/0x30a4 kernel/locking/lockdep.c:5191 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] preempt_schedule_irq+0x78/0x188 kernel/sched/core.c:7189 raw_irqentry_exit_cond_resched+0x30/0x44 kernel/entry/common.c:173 irqentry_exit+0x1b0/0x308 kernel/entry/common.c:216 exit_to_kernel_mode+0x10/0x1c arch/arm64/kernel/entry-common.c:58 __el1_irq arch/arm64/kernel/entry-common.c:500 [inline] el1_interrupt+0x4c/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] class_irqsave_destructor include/linux/irqflags.h:266 [inline] __free_object+0x514/0x720 lib/debugobjects.c:524 free_object lib/debugobjects.c:532 [inline] debug_object_free+0x298/0x3e4 lib/debugobjects.c:976 destroy_hrtimer_on_stack kernel/time/hrtimer.c:448 [inline] hrtimer_nanosleep+0x214/0x2a4 kernel/time/hrtimer.c:2178 common_nsleep+0xa0/0xb8 kernel/time/posix-timers.c:1352 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1398 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1375 [inline] __arm64_sys_clock_nanosleep+0x334/0x370 kernel/time/posix-timers.c:1375 __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: 6572 Comm: syz-executor 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_irq_inversion_bug+0x1f8/0x1fc kernel/locking/lockdep.c:4125 mark_lock_irq+0x3b4/0x47c kernel/locking/lockdep.c:-1 mark_lock+0x170/0x1d0 kernel/locking/lockdep.c:4753 mark_usage kernel/locking/lockdep.c:4662 [inline] __lock_acquire+0x9a0/0x30a4 kernel/locking/lockdep.c:5191 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] (P) arch_local_irq_enable arch/arm64/include/asm/irqflags.h:48 [inline] (P) preempt_schedule_irq+0x78/0x188 kernel/sched/core.c:7189 (P) raw_irqentry_exit_cond_resched+0x30/0x44 kernel/entry/common.c:173 irqentry_exit+0x1b0/0x308 kernel/entry/common.c:216 exit_to_kernel_mode+0x10/0x1c arch/arm64/kernel/entry-common.c:58 __el1_irq arch/arm64/kernel/entry-common.c:500 [inline] el1_interrupt+0x4c/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] (P) arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] (P) class_irqsave_destructor include/linux/irqflags.h:266 [inline] (P) __free_object+0x514/0x720 lib/debugobjects.c:524 (P) free_object lib/debugobjects.c:532 [inline] debug_object_free+0x298/0x3e4 lib/debugobjects.c:976 destroy_hrtimer_on_stack kernel/time/hrtimer.c:448 [inline] hrtimer_nanosleep+0x214/0x2a4 kernel/time/hrtimer.c:2178 common_nsleep+0xa0/0xb8 kernel/time/posix-timers.c:1352 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1398 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1375 [inline] __arm64_sys_clock_nanosleep+0x334/0x370 kernel/time/posix-timers.c:1375 __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 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup