last executing test programs:
kernel console output (not intermixed with test programs):
[ 58.977782][ T60] ------------[ cut here ]------------
[ 58.983343][ T60] WARNING: ./include/linux/backing-dev.h:243 at __folio_start_writeback+0x8e7/0xa50, CPU#0: kworker/u8:4/60
[ 58.995190][ T60] Modules linked in:
[ 58.999201][ T60] CPU: 0 UID: 0 PID: 60 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full)
[ 59.008516][ T60] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
[ 59.018607][ T60] Workqueue: writeback wb_workfn (flush-8:0)
[ 59.024594][ T60] RIP: 0010:__folio_start_writeback+0x8e7/0xa50
[ 59.030865][ T60] Code: 8b 05 2d 87 eb 10 48 3b 84 24 20 01 00 00 75 3b 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 10 8d 8f 09 cc e8 1a fa c5 ff 90 <0f> 0b 90 e9 e5 fb ff ff e8 0c fa c5 ff 48 c7 c7 20 ff 5f 8e 4c 89
[ 59.050519][ T60] RSP: 0018:ffffc9000211eea0 EFLAGS: 00010293
[ 59.056594][ T60] RAX: ffffffff81faf916 RBX: ffffea0000932780 RCX: ffff88801c3c5a00
[ 59.064613][ T60] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 59.072637][ T60] RBP: ffffc9000211f010 R08: ffffc9000211ef97 R09: 0000000000000000
[ 59.080633][ T60] R10: ffffc9000211ef80 R11: fffff52000423df3 R12: ffffea0000932788
[ 59.088636][ T60] R13: 0000000000000000 R14: ffff888023017000 R15: ffff888023016de0
[ 59.096670][ T60] FS: 0000000000000000(0000) GS:ffff8881257b8000(0000) knlGS:0000000000000000
[ 59.106111][ T60] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 59.112749][ T60] CR2: 00005581d9aeef70 CR3: 000000007b9c8000 CR4: 00000000003526f0
[ 59.120762][ T60] Call Trace:
[ 59.124043][ T60]
[ 59.127021][ T60] ? __pfx___folio_start_writeback+0x10/0x10
[ 59.133005][ T60] ? __pfx_folio_clear_dirty_for_io+0x10/0x10
[ 59.139121][ T60] ? stack_trace_save+0x9c/0xe0
[ 59.143985][ T60] __block_write_full_folio+0x75f/0xe10
[ 59.149569][ T60] ? __pfx_blkdev_get_block+0x10/0x10
[ 59.155036][ T60] blkdev_writepages+0xd1/0x170
[ 59.159969][ T60] ? __pfx_blkdev_writepages+0x10/0x10
[ 59.165462][ T60] ? __pfx_blkdev_writepages+0x10/0x10
[ 59.170975][ T60] do_writepages+0x32e/0x550
[ 59.175592][ T60] __writeback_single_inode+0x145/0xff0
[ 59.181178][ T60] ? wbc_attach_and_unlock_inode+0x3f0/0x5d0
[ 59.187221][ T60] writeback_sb_inodes+0x6c7/0x1010
[ 59.192425][ T60] ? __pfx_writeback_sb_inodes+0x10/0x10
[ 59.198204][ T60] ? __pfx_down_read_trylock+0x10/0x10
[ 59.203667][ T60] ? __pfx___up_read+0x10/0x10
[ 59.208511][ T60] __writeback_inodes_wb+0x111/0x240
[ 59.213813][ T60] wb_writeback+0x44f/0xaf0
[ 59.218387][ T60] ? queue_io+0x2f1/0x590
[ 59.222722][ T60] ? __pfx_wb_writeback+0x10/0x10
[ 59.227802][ T60] wb_workfn+0xaef/0xef0
[ 59.232050][ T60] ? __pfx_wb_workfn+0x10/0x10
[ 59.236795][ T60] ? __lock_acquire+0xab9/0xd20
[ 59.241708][ T60] ? process_scheduled_works+0x9ef/0x17b0
[ 59.247486][ T60] ? _raw_spin_unlock_irq+0x23/0x50
[ 59.252702][ T60] ? process_scheduled_works+0x9ef/0x17b0
[ 59.258484][ T60] ? process_scheduled_works+0x9ef/0x17b0
[ 59.264226][ T60] process_scheduled_works+0xade/0x17b0
[ 59.269898][ T60] ? __pfx_process_scheduled_works+0x10/0x10
[ 59.275909][ T60] worker_thread+0x8a0/0xda0
[ 59.280587][ T60] ? __pfx__raw_spin_unlock_irqrestore+0x10/0x10
[ 59.286985][ T60] ? __kthread_parkme+0x7b/0x200
[ 59.291955][ T60] kthread+0x70e/0x8a0
[ 59.296043][ T60] ? __pfx_worker_thread+0x10/0x10
[ 59.301246][ T60] ? __pfx_kthread+0x10/0x10
[ 59.305854][ T60] ? _raw_spin_unlock_irq+0x23/0x50
[ 59.311137][ T60] ? lockdep_hardirqs_on+0x9c/0x150
[ 59.316355][ T60] ? __pfx_kthread+0x10/0x10
[ 59.321068][ T60] ret_from_fork+0x47c/0x820
[ 59.325681][ T60] ? __pfx_ret_from_fork+0x10/0x10
[ 59.330869][ T60] ? __switch_to_asm+0x39/0x70
[ 59.335643][ T60] ? __switch_to_asm+0x33/0x70
[ 59.340478][ T60] ? __pfx_kthread+0x10/0x10
[ 59.345085][ T60] ret_from_fork_asm+0x1a/0x30
[ 59.349956][ T60]
[ 59.352983][ T60] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 59.360273][ T60] CPU: 0 UID: 0 PID: 60 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full)
[ 59.369561][ T60] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
[ 59.379620][ T60] Workqueue: writeback wb_workfn (flush-8:0)
[ 59.385622][ T60] Call Trace:
[ 59.388903][ T60]
[ 59.391836][ T60] dump_stack_lvl+0x99/0x250
[ 59.396441][ T60] ? __asan_memcpy+0x40/0x70
[ 59.401045][ T60] ? __pfx_dump_stack_lvl+0x10/0x10
[ 59.406260][ T60] ? __pfx__printk+0x10/0x10
[ 59.410875][ T60] vpanic+0x229/0x6d0
[ 59.414852][ T60] ? __pfx_vpanic+0x10/0x10
[ 59.419340][ T60] ? is_bpf_text_address+0x292/0x2b0
[ 59.424608][ T60] ? is_bpf_text_address+0x26/0x2b0
[ 59.429796][ T60] panic+0xb9/0xc0
[ 59.433508][ T60] ? __pfx_panic+0x10/0x10
[ 59.437921][ T60] ? ret_from_fork_asm+0x1a/0x30
[ 59.442864][ T60] __warn+0x334/0x4c0
[ 59.446834][ T60] ? __folio_start_writeback+0x8e7/0xa50
[ 59.452471][ T60] ? __folio_start_writeback+0x8e7/0xa50
[ 59.458110][ T60] report_bug+0x2be/0x4f0
[ 59.462435][ T60] ? __folio_start_writeback+0x8e7/0xa50
[ 59.468174][ T60] ? __folio_start_writeback+0x8e7/0xa50
[ 59.473792][ T60] ? __folio_start_writeback+0x8e9/0xa50
[ 59.479407][ T60] handle_bug+0x84/0x160
[ 59.483638][ T60] exc_invalid_op+0x1a/0x50
[ 59.488131][ T60] asm_exc_invalid_op+0x1a/0x20
[ 59.492966][ T60] RIP: 0010:__folio_start_writeback+0x8e7/0xa50
[ 59.499217][ T60] Code: 8b 05 2d 87 eb 10 48 3b 84 24 20 01 00 00 75 3b 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 10 8d 8f 09 cc e8 1a fa c5 ff 90 <0f> 0b 90 e9 e5 fb ff ff e8 0c fa c5 ff 48 c7 c7 20 ff 5f 8e 4c 89
[ 59.519286][ T60] RSP: 0018:ffffc9000211eea0 EFLAGS: 00010293
[ 59.525343][ T60] RAX: ffffffff81faf916 RBX: ffffea0000932780 RCX: ffff88801c3c5a00
[ 59.533299][ T60] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 59.541258][ T60] RBP: ffffc9000211f010 R08: ffffc9000211ef97 R09: 0000000000000000
[ 59.549216][ T60] R10: ffffc9000211ef80 R11: fffff52000423df3 R12: ffffea0000932788
[ 59.557179][ T60] R13: 0000000000000000 R14: ffff888023017000 R15: ffff888023016de0
[ 59.565142][ T60] ? __folio_start_writeback+0x8e6/0xa50
[ 59.570781][ T60] ? __pfx___folio_start_writeback+0x10/0x10
[ 59.576749][ T60] ? __pfx_folio_clear_dirty_for_io+0x10/0x10
[ 59.582802][ T60] ? stack_trace_save+0x9c/0xe0
[ 59.587651][ T60] __block_write_full_folio+0x75f/0xe10
[ 59.593270][ T60] ? __pfx_blkdev_get_block+0x10/0x10
[ 59.598646][ T60] blkdev_writepages+0xd1/0x170
[ 59.603482][ T60] ? __pfx_blkdev_writepages+0x10/0x10
[ 59.608935][ T60] ? __pfx_blkdev_writepages+0x10/0x10
[ 59.614376][ T60] do_writepages+0x32e/0x550
[ 59.618962][ T60] __writeback_single_inode+0x145/0xff0
[ 59.624510][ T60] ? wbc_attach_and_unlock_inode+0x3f0/0x5d0
[ 59.630500][ T60] writeback_sb_inodes+0x6c7/0x1010
[ 59.635708][ T60] ? __pfx_writeback_sb_inodes+0x10/0x10
[ 59.641373][ T60] ? __pfx_down_read_trylock+0x10/0x10
[ 59.646829][ T60] ? __pfx___up_read+0x10/0x10
[ 59.651603][ T60] __writeback_inodes_wb+0x111/0x240
[ 59.656890][ T60] wb_writeback+0x44f/0xaf0
[ 59.661394][ T60] ? queue_io+0x2f1/0x590
[ 59.665709][ T60] ? __pfx_wb_writeback+0x10/0x10
[ 59.670747][ T60] wb_workfn+0xaef/0xef0
[ 59.674983][ T60] ? __pfx_wb_workfn+0x10/0x10
[ 59.679731][ T60] ? __lock_acquire+0xab9/0xd20
[ 59.684578][ T60] ? process_scheduled_works+0x9ef/0x17b0
[ 59.690289][ T60] ? _raw_spin_unlock_irq+0x23/0x50
[ 59.695473][ T60] ? process_scheduled_works+0x9ef/0x17b0
[ 59.701182][ T60] ? process_scheduled_works+0x9ef/0x17b0
[ 59.706887][ T60] process_scheduled_works+0xade/0x17b0
[ 59.712447][ T60] ? __pfx_process_scheduled_works+0x10/0x10
[ 59.718424][ T60] worker_thread+0x8a0/0xda0
[ 59.723003][ T60] ? __pfx__raw_spin_unlock_irqrestore+0x10/0x10
[ 59.729326][ T60] ? __kthread_parkme+0x7b/0x200
[ 59.734257][ T60] kthread+0x70e/0x8a0
[ 59.738316][ T60] ? __pfx_worker_thread+0x10/0x10
[ 59.743426][ T60] ? __pfx_kthread+0x10/0x10
[ 59.748015][ T60] ? _raw_spin_unlock_irq+0x23/0x50
[ 59.753202][ T60] ? lockdep_hardirqs_on+0x9c/0x150
[ 59.758387][ T60] ? __pfx_kthread+0x10/0x10
[ 59.762968][ T60] ret_from_fork+0x47c/0x820
[ 59.767546][ T60] ? __pfx_ret_from_fork+0x10/0x10
[ 59.772652][ T60] ? __switch_to_asm+0x39/0x70
[ 59.777403][ T60] ? __switch_to_asm+0x33/0x70
[ 59.782150][ T60] ? __pfx_kthread+0x10/0x10
[ 59.786731][ T60] ret_from_fork_asm+0x1a/0x30
[ 59.791500][ T60]
[ 59.797769][ T60] Kernel Offset: disabled
[ 59.802083][ T60] Rebooting in 86400 seconds..