last executing test programs:
kernel console output (not intermixed with test programs):
_folio_start_writeback+0x9d5/0xb70
[ 59.433258][ T995] Code: 28 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 ae a1 29 00 49 8b 07 25 ff 3f 00 00 e9 1b fa ff ff e8 6c 04 c6 ff 90 <0f> 0b 90 e9 d6 fb ff ff e8 5e 04 c6 ff 48 c7 c7 60 f8 5f 8e 4c 89
[ 59.452998][ T995] RSP: 0018:ffffc900037d6ea0 EFLAGS: 00010293
[ 59.459152][ T995] RAX: ffffffff81fad144 RBX: ffffea000503fe40 RCX: ffff8880263d0000
[ 59.467144][ T995] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 59.475230][ T995] RBP: ffffc900037d7010 R08: ffffc900037d6f97 R09: 0000000000000000
[ 59.483450][ T995] R10: ffffc900037d6f80 R11: fffff520006fadf3 R12: ffffea000503fe48
[ 59.491512][ T995] R13: 0000000000000000 R14: ffff888025c0c200 R15: ffff888025c0bfe0
[ 59.499727][ T995] FS: 0000000000000000(0000) GS:ffff8881258c3000(0000) knlGS:0000000000000000
[ 59.508682][ T995] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 59.515479][ T995] CR2: 00005632d7d87f70 CR3: 000000003361c000 CR4: 00000000003526f0
[ 59.523545][ T995] Call Trace:
[ 59.526830][ T995]
[ 59.529814][ T995] ? folio_clear_dirty_for_io+0x226/0x880
[ 59.535571][ T995] ? __pfx___folio_start_writeback+0x10/0x10
[ 59.541639][ T995] ? __pfx_folio_clear_dirty_for_io+0x10/0x10
[ 59.547738][ T995] ? stack_trace_save+0x9c/0xe0
[ 59.552727][ T995] __block_write_full_folio+0x75f/0xe10
[ 59.558305][ T995] ? __pfx_blkdev_get_block+0x10/0x10
[ 59.563997][ T995] blkdev_writepages+0xd1/0x170
[ 59.569021][ T995] ? __pfx_blkdev_writepages+0x10/0x10
[ 59.574547][ T995] ? __pfx_blkdev_writepages+0x10/0x10
[ 59.580526][ T995] do_writepages+0x32e/0x550
[ 59.585172][ T995] __writeback_single_inode+0x145/0xff0
[ 59.590803][ T995] ? wbc_attach_and_unlock_inode+0x3f0/0x5d0
[ 59.596812][ T995] writeback_sb_inodes+0x6c7/0x1010
[ 59.602563][ T995] ? __pfx_writeback_sb_inodes+0x10/0x10
[ 59.608261][ T995] ? __pfx_down_read_trylock+0x10/0x10
[ 59.613821][ T995] ? __pfx___up_read+0x10/0x10
[ 59.618628][ T995] __writeback_inodes_wb+0x111/0x240
[ 59.624178][ T995] wb_writeback+0x44f/0xaf0
[ 59.628766][ T995] ? queue_io+0x371/0x590
[ 59.633115][ T995] ? __pfx_wb_writeback+0x10/0x10
[ 59.638162][ T995] wb_workfn+0xaef/0xef0
[ 59.642503][ T995] ? __pfx_wb_workfn+0x10/0x10
[ 59.647299][ T995] ? __lock_acquire+0xab9/0xd20
[ 59.652316][ T995] ? process_scheduled_works+0x9ef/0x17b0
[ 59.658123][ T995] ? _raw_spin_unlock_irq+0x23/0x50
[ 59.663413][ T995] ? process_scheduled_works+0x9ef/0x17b0
[ 59.669202][ T995] ? process_scheduled_works+0x9ef/0x17b0
[ 59.675246][ T995] process_scheduled_works+0xae1/0x17b0
[ 59.680931][ T995] ? __pfx_process_scheduled_works+0x10/0x10
[ 59.686951][ T995] worker_thread+0x8a0/0xda0
[ 59.691661][ T995] ? __pfx__raw_spin_unlock_irqrestore+0x10/0x10
[ 59.698061][ T995] ? __kthread_parkme+0x7b/0x200
[ 59.703116][ T995] kthread+0x711/0x8a0
[ 59.707212][ T995] ? __pfx_worker_thread+0x10/0x10
[ 59.712430][ T995] ? __pfx_kthread+0x10/0x10
[ 59.717053][ T995] ? _raw_spin_unlock_irq+0x23/0x50
[ 59.722343][ T995] ? lockdep_hardirqs_on+0x9c/0x150
[ 59.727578][ T995] ? __pfx_kthread+0x10/0x10
[ 59.732269][ T995] ret_from_fork+0x47c/0x820
[ 59.736878][ T995] ? __pfx_ret_from_fork+0x10/0x10
[ 59.742077][ T995] ? __switch_to_asm+0x39/0x70
[ 59.746896][ T995] ? __switch_to_asm+0x33/0x70
[ 59.752069][ T995] ? __pfx_kthread+0x10/0x10
[ 59.756689][ T995] ret_from_fork_asm+0x1a/0x30
[ 59.761559][ T995]
[ 59.764646][ T995] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 59.771943][ T995] CPU: 1 UID: 0 PID: 995 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full)
[ 59.781310][ T995] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
[ 59.791537][ T995] Workqueue: writeback wb_workfn (flush-8:0)
[ 59.798053][ T995] Call Trace:
[ 59.801496][ T995]
[ 59.804505][ T995] dump_stack_lvl+0x99/0x250
[ 59.809093][ T995] ? __asan_memcpy+0x40/0x70
[ 59.813858][ T995] ? __pfx_dump_stack_lvl+0x10/0x10
[ 59.819048][ T995] ? __pfx__printk+0x10/0x10
[ 59.823647][ T995] vpanic+0x281/0x750
[ 59.827624][ T995] ? __pfx_vpanic+0x10/0x10
[ 59.832119][ T995] ? is_bpf_text_address+0x292/0x2b0
[ 59.837394][ T995] ? is_bpf_text_address+0x26/0x2b0
[ 59.842584][ T995] panic+0xb9/0xc0
[ 59.846298][ T995] ? __pfx_panic+0x10/0x10
[ 59.850717][ T995] ? ret_from_fork_asm+0x1a/0x30
[ 59.855652][ T995] __warn+0x334/0x4c0
[ 59.859623][ T995] ? __folio_start_writeback+0x9d5/0xb70
[ 59.865246][ T995] ? __folio_start_writeback+0x9d5/0xb70
[ 59.870951][ T995] report_bug+0x2be/0x4f0
[ 59.875291][ T995] ? __folio_start_writeback+0x9d5/0xb70
[ 59.880910][ T995] ? __folio_start_writeback+0x9d5/0xb70
[ 59.886796][ T995] ? __folio_start_writeback+0x9d7/0xb70
[ 59.892863][ T995] handle_bug+0x84/0x160
[ 59.897181][ T995] exc_invalid_op+0x1a/0x50
[ 59.901669][ T995] asm_exc_invalid_op+0x1a/0x20
[ 59.906507][ T995] RIP: 0010:__folio_start_writeback+0x9d5/0xb70
[ 59.912744][ T995] Code: 28 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 ae a1 29 00 49 8b 07 25 ff 3f 00 00 e9 1b fa ff ff e8 6c 04 c6 ff 90 <0f> 0b 90 e9 d6 fb ff ff e8 5e 04 c6 ff 48 c7 c7 60 f8 5f 8e 4c 89
[ 59.932604][ T995] RSP: 0018:ffffc900037d6ea0 EFLAGS: 00010293
[ 59.938666][ T995] RAX: ffffffff81fad144 RBX: ffffea000503fe40 RCX: ffff8880263d0000
[ 59.946682][ T995] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 59.954989][ T995] RBP: ffffc900037d7010 R08: ffffc900037d6f97 R09: 0000000000000000
[ 59.962945][ T995] R10: ffffc900037d6f80 R11: fffff520006fadf3 R12: ffffea000503fe48
[ 59.970903][ T995] R13: 0000000000000000 R14: ffff888025c0c200 R15: ffff888025c0bfe0
[ 59.978957][ T995] ? __folio_start_writeback+0x9d4/0xb70
[ 59.984592][ T995] ? folio_clear_dirty_for_io+0x226/0x880
[ 59.990313][ T995] ? __pfx___folio_start_writeback+0x10/0x10
[ 59.996285][ T995] ? __pfx_folio_clear_dirty_for_io+0x10/0x10
[ 60.002353][ T995] ? stack_trace_save+0x9c/0xe0
[ 60.007639][ T995] __block_write_full_folio+0x75f/0xe10
[ 60.013465][ T995] ? __pfx_blkdev_get_block+0x10/0x10
[ 60.018941][ T995] blkdev_writepages+0xd1/0x170
[ 60.023958][ T995] ? __pfx_blkdev_writepages+0x10/0x10
[ 60.029511][ T995] ? __pfx_blkdev_writepages+0x10/0x10
[ 60.034967][ T995] do_writepages+0x32e/0x550
[ 60.039572][ T995] __writeback_single_inode+0x145/0xff0
[ 60.045104][ T995] ? wbc_attach_and_unlock_inode+0x3f0/0x5d0
[ 60.051115][ T995] writeback_sb_inodes+0x6c7/0x1010
[ 60.056407][ T995] ? __pfx_writeback_sb_inodes+0x10/0x10
[ 60.062055][ T995] ? __pfx_down_read_trylock+0x10/0x10
[ 60.067506][ T995] ? __pfx___up_read+0x10/0x10
[ 60.072304][ T995] __writeback_inodes_wb+0x111/0x240
[ 60.077584][ T995] wb_writeback+0x44f/0xaf0
[ 60.082080][ T995] ? queue_io+0x371/0x590
[ 60.086573][ T995] ? __pfx_wb_writeback+0x10/0x10
[ 60.091597][ T995] wb_workfn+0xaef/0xef0
[ 60.095983][ T995] ? __pfx_wb_workfn+0x10/0x10
[ 60.100862][ T995] ? __lock_acquire+0xab9/0xd20
[ 60.105740][ T995] ? process_scheduled_works+0x9ef/0x17b0
[ 60.111577][ T995] ? _raw_spin_unlock_irq+0x23/0x50
[ 60.116773][ T995] ? process_scheduled_works+0x9ef/0x17b0
[ 60.122488][ T995] ? process_scheduled_works+0x9ef/0x17b0
[ 60.128288][ T995] process_scheduled_works+0xae1/0x17b0
[ 60.133846][ T995] ? __pfx_process_scheduled_works+0x10/0x10
[ 60.139827][ T995] worker_thread+0x8a0/0xda0
[ 60.144409][ T995] ? __pfx__raw_spin_unlock_irqrestore+0x10/0x10
[ 60.150732][ T995] ? __kthread_parkme+0x7b/0x200
[ 60.155667][ T995] kthread+0x711/0x8a0
[ 60.159729][ T995] ? __pfx_worker_thread+0x10/0x10
[ 60.164831][ T995] ? __pfx_kthread+0x10/0x10
[ 60.169416][ T995] ? _raw_spin_unlock_irq+0x23/0x50
[ 60.174616][ T995] ? lockdep_hardirqs_on+0x9c/0x150
[ 60.179834][ T995] ? __pfx_kthread+0x10/0x10
[ 60.184420][ T995] ret_from_fork+0x47c/0x820
[ 60.189002][ T995] ? __pfx_ret_from_fork+0x10/0x10
[ 60.194127][ T995] ? __switch_to_asm+0x39/0x70
[ 60.198879][ T995] ? __switch_to_asm+0x33/0x70
[ 60.203638][ T995] ? __pfx_kthread+0x10/0x10
[ 60.208224][ T995] ret_from_fork_asm+0x1a/0x30
[ 60.213092][ T995]
[ 60.216361][ T995] Kernel Offset: disabled
[ 60.220773][ T995] Rebooting in 86400 seconds..