last executing test programs:
kernel console output (not intermixed with test programs):
[ 64.999309][ T1337] ------------[ cut here ]------------
[ 65.004913][ T1337] WARNING: ./include/linux/backing-dev.h:243 at __folio_start_writeback+0x8e7/0xa50, CPU#1: kworker/u8:6/1337
[ 65.017103][ T1337] Modules linked in:
[ 65.021143][ T1337] CPU: 1 UID: 0 PID: 1337 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full)
[ 65.030648][ T1337] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
[ 65.040736][ T1337] Workqueue: writeback wb_workfn (flush-8:0)
[ 65.046740][ T1337] RIP: 0010:__folio_start_writeback+0x8e7/0xa50
[ 65.053445][ T1337] 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
[ 65.073161][ T1337] RSP: 0018:ffffc900040f6ea0 EFLAGS: 00010293
[ 65.079296][ T1337] RAX: ffffffff81faf916 RBX: ffffea0000920200 RCX: ffff8880275dda00
[ 65.087377][ T1337] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
Warning: Permanently added '10.128.1.167' (ED25519) to the list of known hosts.
[ 65.095402][ T1337] RBP: ffffc900040f7010 R08: ffffc900040f6f97 R09: 0000000000000000
[ 65.103411][ T1337] R10: ffffc900040f6f80 R11: fffff5200081edf3 R12: ffffea0000920208
[ 65.111428][ T1337] R13: 0000000000000000 R14: ffff888148defb80 R15: ffff888148def960
[ 65.119532][ T1337] FS: 0000000000000000(0000) GS:ffff8881258b8000(0000) knlGS:0000000000000000
[ 65.128520][ T1337] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 65.135108][ T1337] CR2: 000056302ced00d0 CR3: 000000007ce4c000 CR4: 00000000003526f0
[ 65.143128][ T1337] Call Trace:
[ 65.146423][ T1337]
[ 65.149415][ T1337] ? __pfx___folio_start_writeback+0x10/0x10
[ 65.155402][ T1337] ? __pfx_folio_clear_dirty_for_io+0x10/0x10
[ 65.161673][ T1337] ? stack_trace_save+0x9c/0xe0
[ 65.166555][ T1337] __block_write_full_folio+0x75f/0xe10
[ 65.172171][ T1337] ? __pfx_blkdev_get_block+0x10/0x10
[ 65.177545][ T1337] blkdev_writepages+0xd1/0x170
[ 65.182422][ T1337] ? __pfx_blkdev_writepages+0x10/0x10
[ 65.187932][ T1337] ? __pfx_blkdev_writepages+0x10/0x10
[ 65.193455][ T1337] do_writepages+0x32e/0x550
[ 65.198067][ T1337] __writeback_single_inode+0x145/0xff0
[ 65.203644][ T1337] ? wbc_attach_and_unlock_inode+0x3f0/0x5d0
[ 65.209681][ T1337] writeback_sb_inodes+0x6c7/0x1010
[ 65.214910][ T1337] ? __pfx_writeback_sb_inodes+0x10/0x10
[ 65.220612][ T1337] ? __pfx_down_read_trylock+0x10/0x10
[ 65.226170][ T1337] ? __pfx___up_read+0x10/0x10
[ 65.231003][ T1337] __writeback_inodes_wb+0x111/0x240
[ 65.236323][ T1337] wb_writeback+0x44f/0xaf0
[ 65.240915][ T1337] ? queue_io+0x2f1/0x590
[ 65.245267][ T1337] ? __pfx_wb_writeback+0x10/0x10
[ 65.250394][ T1337] wb_workfn+0xaef/0xef0
[ 65.254663][ T1337] ? __pfx_wb_workfn+0x10/0x10
[ 65.259496][ T1337] ? __lock_acquire+0xab9/0xd20
[ 65.264453][ T1337] ? process_scheduled_works+0x9ef/0x17b0
[ 65.270325][ T1337] ? _raw_spin_unlock_irq+0x23/0x50
[ 65.275543][ T1337] ? process_scheduled_works+0x9ef/0x17b0
[ 65.281299][ T1337] ? process_scheduled_works+0x9ef/0x17b0
[ 65.287026][ T1337] process_scheduled_works+0xade/0x17b0
[ 65.292758][ T1337] ? __pfx_process_scheduled_works+0x10/0x10
[ 65.298785][ T1337] worker_thread+0x8a0/0xda0
[ 65.303381][ T1337] ? __pfx__raw_spin_unlock_irqrestore+0x10/0x10
[ 65.309759][ T1337] ? __kthread_parkme+0x7b/0x200
[ 65.314703][ T1337] kthread+0x70e/0x8a0
[ 65.318819][ T1337] ? __pfx_worker_thread+0x10/0x10
[ 65.323951][ T1337] ? __pfx_kthread+0x10/0x10
[ 65.328598][ T1337] ? _raw_spin_unlock_irq+0x23/0x50
[ 65.333797][ T1337] ? lockdep_hardirqs_on+0x9c/0x150
[ 65.339082][ T1337] ? __pfx_kthread+0x10/0x10
[ 65.343694][ T1337] ret_from_fork+0x47c/0x820
[ 65.348300][ T1337] ? __pfx_ret_from_fork+0x10/0x10
[ 65.353481][ T1337] ? __switch_to_asm+0x39/0x70
[ 65.358254][ T1337] ? __switch_to_asm+0x33/0x70
[ 65.363071][ T1337] ? __pfx_kthread+0x10/0x10
[ 65.367681][ T1337] ret_from_fork_asm+0x1a/0x30
[ 65.372541][ T1337]
[ 65.375569][ T1337] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 65.382850][ T1337] CPU: 1 UID: 0 PID: 1337 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full)
[ 65.392399][ T1337] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
[ 65.402491][ T1337] Workqueue: writeback wb_workfn (flush-8:0)
[ 65.408507][ T1337] Call Trace:
[ 65.411793][ T1337]
[ 65.414789][ T1337] dump_stack_lvl+0x99/0x250
[ 65.419417][ T1337] ? __asan_memcpy+0x40/0x70
[ 65.424060][ T1337] ? __pfx_dump_stack_lvl+0x10/0x10
[ 65.429293][ T1337] ? __pfx__printk+0x10/0x10
[ 65.434349][ T1337] vpanic+0x229/0x6d0
[ 65.438347][ T1337] ? __pfx_vpanic+0x10/0x10
[ 65.442953][ T1337] ? is_bpf_text_address+0x292/0x2b0
[ 65.448251][ T1337] ? is_bpf_text_address+0x26/0x2b0
[ 65.453474][ T1337] panic+0xb9/0xc0
[ 65.457193][ T1337] ? __pfx_panic+0x10/0x10
[ 65.461606][ T1337] ? ret_from_fork_asm+0x1a/0x30
[ 65.466538][ T1337] __warn+0x334/0x4c0
[ 65.470513][ T1337] ? __folio_start_writeback+0x8e7/0xa50
[ 65.476134][ T1337] ? __folio_start_writeback+0x8e7/0xa50
[ 65.481749][ T1337] report_bug+0x2be/0x4f0
[ 65.486078][ T1337] ? __folio_start_writeback+0x8e7/0xa50
[ 65.491786][ T1337] ? __folio_start_writeback+0x8e7/0xa50
[ 65.497403][ T1337] ? __folio_start_writeback+0x8e9/0xa50
[ 65.503020][ T1337] handle_bug+0x84/0x160
[ 65.507251][ T1337] exc_invalid_op+0x1a/0x50
[ 65.511742][ T1337] asm_exc_invalid_op+0x1a/0x20
[ 65.516579][ T1337] RIP: 0010:__folio_start_writeback+0x8e7/0xa50
[ 65.522805][ T1337] 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
[ 65.542396][ T1337] RSP: 0018:ffffc900040f6ea0 EFLAGS: 00010293
[ 65.548544][ T1337] RAX: ffffffff81faf916 RBX: ffffea0000920200 RCX: ffff8880275dda00
[ 65.556502][ T1337] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 65.564459][ T1337] RBP: ffffc900040f7010 R08: ffffc900040f6f97 R09: 0000000000000000
[ 65.572417][ T1337] R10: ffffc900040f6f80 R11: fffff5200081edf3 R12: ffffea0000920208
[ 65.580410][ T1337] R13: 0000000000000000 R14: ffff888148defb80 R15: ffff888148def960
[ 65.588404][ T1337] ? __folio_start_writeback+0x8e6/0xa50
[ 65.594052][ T1337] ? __pfx___folio_start_writeback+0x10/0x10
[ 65.600025][ T1337] ? __pfx_folio_clear_dirty_for_io+0x10/0x10
[ 65.606080][ T1337] ? stack_trace_save+0x9c/0xe0
[ 65.610932][ T1337] __block_write_full_folio+0x75f/0xe10
[ 65.616474][ T1337] ? __pfx_blkdev_get_block+0x10/0x10
[ 65.621832][ T1337] blkdev_writepages+0xd1/0x170
[ 65.626665][ T1337] ? __pfx_blkdev_writepages+0x10/0x10
[ 65.632120][ T1337] ? __pfx_blkdev_writepages+0x10/0x10
[ 65.637565][ T1337] do_writepages+0x32e/0x550
[ 65.642204][ T1337] __writeback_single_inode+0x145/0xff0
[ 65.647736][ T1337] ? wbc_attach_and_unlock_inode+0x3f0/0x5d0
[ 65.653709][ T1337] writeback_sb_inodes+0x6c7/0x1010
[ 65.658919][ T1337] ? __pfx_writeback_sb_inodes+0x10/0x10
[ 65.664570][ T1337] ? __pfx_down_read_trylock+0x10/0x10
[ 65.670017][ T1337] ? __pfx___up_read+0x10/0x10
[ 65.674880][ T1337] __writeback_inodes_wb+0x111/0x240
[ 65.680255][ T1337] wb_writeback+0x44f/0xaf0
[ 65.684752][ T1337] ? queue_io+0x2f1/0x590
[ 65.689070][ T1337] ? __pfx_wb_writeback+0x10/0x10
[ 65.694094][ T1337] wb_workfn+0xaef/0xef0
[ 65.698330][ T1337] ? __pfx_wb_workfn+0x10/0x10
[ 65.703085][ T1337] ? __lock_acquire+0xab9/0xd20
[ 65.707927][ T1337] ? process_scheduled_works+0x9ef/0x17b0
[ 65.713658][ T1337] ? _raw_spin_unlock_irq+0x23/0x50
[ 65.718839][ T1337] ? process_scheduled_works+0x9ef/0x17b0
[ 65.724542][ T1337] ? process_scheduled_works+0x9ef/0x17b0
[ 65.730245][ T1337] process_scheduled_works+0xade/0x17b0
[ 65.735799][ T1337] ? __pfx_process_scheduled_works+0x10/0x10
[ 65.741842][ T1337] worker_thread+0x8a0/0xda0
[ 65.746450][ T1337] ? __pfx__raw_spin_unlock_irqrestore+0x10/0x10
[ 65.752777][ T1337] ? __kthread_parkme+0x7b/0x200
[ 65.757721][ T1337] kthread+0x70e/0x8a0
[ 65.761796][ T1337] ? __pfx_worker_thread+0x10/0x10
[ 65.766892][ T1337] ? __pfx_kthread+0x10/0x10
[ 65.771472][ T1337] ? _raw_spin_unlock_irq+0x23/0x50
[ 65.776664][ T1337] ? lockdep_hardirqs_on+0x9c/0x150
[ 65.781843][ T1337] ? __pfx_kthread+0x10/0x10
[ 65.786428][ T1337] ret_from_fork+0x47c/0x820
[ 65.791006][ T1337] ? __pfx_ret_from_fork+0x10/0x10
[ 65.796108][ T1337] ? __switch_to_asm+0x39/0x70
[ 65.800866][ T1337] ? __switch_to_asm+0x33/0x70
[ 65.805611][ T1337] ? __pfx_kthread+0x10/0x10
[ 65.810204][ T1337] ret_from_fork_asm+0x1a/0x30
[ 65.814961][ T1337]
[ 65.818208][ T1337] Kernel Offset: disabled
[ 65.822521][ T1337] Rebooting in 86400 seconds..