------------[ cut here ]------------ WARNING: ./include/linux/backing-dev.h:243 at inode_to_wb include/linux/backing-dev.h:239 [inline], CPU#0: kworker/u8:5/133 WARNING: ./include/linux/backing-dev.h:243 at __folio_start_writeback+0x9d5/0xb70 mm/page-writeback.c:3027, CPU#0: kworker/u8:5/133 Modules linked in: CPU: 0 UID: 0 PID: 133 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: writeback wb_workfn (flush-8:0) RIP: 0010:inode_to_wb include/linux/backing-dev.h:239 [inline] RIP: 0010:__folio_start_writeback+0x9d5/0xb70 mm/page-writeback.c:3027 Code: 28 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 de a2 29 00 49 8b 07 25 ff 3f 00 00 e9 1b fa ff ff e8 dc f7 c5 ff 90 <0f> 0b 90 e9 d6 fb ff ff e8 ce f7 c5 ff 48 c7 c7 e0 fe 3f 8e 4c 89 RSP: 0018:ffffc90002e86ea0 EFLAGS: 00010293 RAX: ffffffff81facb54 RBX: ffffea0000c3ec40 RCX: ffff888020720000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90002e87010 R08: ffffc90002e86f97 R09: 0000000000000000 R10: ffffc90002e86f80 R11: fffff520005d0df3 R12: ffffea0000c3ec48 R13: 0000000000000000 R14: ffff888148c64d80 R15: ffff888148c64b60 FS: 0000000000000000(0000) GS:ffff8881259f8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faddc789000 CR3: 0000000024276000 CR4: 00000000003526f0 Call Trace: __block_write_full_folio+0x75f/0xe10 fs/buffer.c:1928 blkdev_writepages+0xd1/0x170 block/fops.c:484 do_writepages+0x32b/0x550 mm/page-writeback.c:2604 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline] wb_do_writeback fs/fs-writeback.c:2315 [inline] wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245