last executing test programs:
kernel console output (not intermixed with test programs):
[ 59.811448][ T49] ------------[ cut here ]------------
[ 59.817027][ T49] WARNING: ./include/linux/backing-dev.h:243 at __folio_start_writeback+0x8e7/0xa50, CPU#1: kworker/u8:3/49
[ 59.828683][ T49] Modules linked in:
[ 59.832722][ T49] CPU: 1 UID: 0 PID: 49 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full)
[ 59.842103][ T49] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
[ 59.852213][ T49] Workqueue: writeback wb_workfn (flush-8:0)
[ 59.858305][ T49] RIP: 0010:__folio_start_writeback+0x8e7/0xa50
[ 59.864587][ T49] Code: 8b 05 2d f0 ea 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 90 b5 8d 09 cc e8 1a f7 c5 ff 90 <0f> 0b 90 e9 e5 fb ff ff e8 0c f7 c5 ff 48 c7 c7 a0 03 60 8e 4c 89
[ 59.884252][ T49] RSP: 0018:ffffc90000b96ea0 EFLAGS: 00010293
[ 59.890317][ T49] RAX: ffffffff81fb1016 RBX: ffffea000094ab40 RCX: ffff888143683c00
[ 59.898318][ T49] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 59.906328][ T49] RBP: ffffc90000b97010 R08: ffffc90000b96f97 R09: 0000000000000000
[ 59.914336][ T49] R10: ffffc90000b96f80 R11: fffff52000172df3 R12: ffffea000094ab48
[ 59.922360][ T49] R13: 0000000000000000 R14: ffff88802324cd80 R15: ffff88802324cb60
[ 59.930352][ T49] FS: 0000000000000000(0000) GS:ffff8881258c0000(0000) knlGS:0000000000000000
[ 59.939306][ T49] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 59.945949][ T49] CR2: 00005654677ea000 CR3: 000000000e338000 CR4: 00000000003526f0
[ 59.953979][ T49] Call Trace:
[ 59.957266][ T49]
[ 59.960221][ T49] ? __pfx___folio_start_writeback+0x10/0x10
[ 59.966270][ T49] ? __pfx_folio_clear_dirty_for_io+0x10/0x10
[ 59.972562][ T49] ? stack_trace_save+0x9c/0xe0
[ 59.977425][ T49] __block_write_full_folio+0x75f/0xe10
[ 59.983000][ T49] ? __pfx_blkdev_get_block+0x10/0x10
[ 59.988468][ T49] blkdev_writepages+0xd1/0x170
[ 59.993385][ T49] ? __pfx_blkdev_writepages+0x10/0x10
[ 59.998874][ T49] ? __pfx_blkdev_writepages+0x10/0x10
[ 60.004438][ T49] do_writepages+0x32e/0x550
[ 60.009053][ T49] __writeback_single_inode+0x145/0xff0
[ 60.014661][ T49] ? wbc_attach_and_unlock_inode+0x3f0/0x5d0
[ 60.020737][ T49] writeback_sb_inodes+0x6c7/0x1010
[ 60.025962][ T49] ? __pfx_writeback_sb_inodes+0x10/0x10
[ 60.031672][ T49] ? __pfx_down_read_trylock+0x10/0x10
[ 60.037161][ T49] ? __pfx___up_read+0x10/0x10
[ 60.042001][ T49] __writeback_inodes_wb+0x111/0x240
[ 60.047318][ T49] wb_writeback+0x44f/0xaf0
[ 60.051865][ T49] ? queue_io+0x331/0x590
[ 60.056230][ T49] ? __pfx_wb_writeback+0x10/0x10
[ 60.061335][ T49] wb_workfn+0xaef/0xef0
[ 60.065597][ T49] ? __pfx_wb_workfn+0x10/0x10
[ 60.070355][ T49] ? __lock_acquire+0xab9/0xd20
[ 60.075265][ T49] ? process_scheduled_works+0x9ef/0x17b0
[ 60.081065][ T49] ? _raw_spin_unlock_irq+0x23/0x50
[ 60.086286][ T49] ? process_scheduled_works+0x9ef/0x17b0
[ 60.092048][ T49] ? process_scheduled_works+0x9ef/0x17b0
[ 60.097780][ T49] process_scheduled_works+0xade/0x17b0
[ 60.103404][ T49] ? __pfx_process_scheduled_works+0x10/0x10
[ 60.109444][ T49] worker_thread+0x8a0/0xda0
[ 60.114119][ T49] kthread+0x70e/0x8a0
[ 60.118215][ T49] ? __pfx_worker_thread+0x10/0x10
[ 60.123405][ T49] ? __pfx_kthread+0x10/0x10
[ 60.128023][ T49] ? _raw_spin_unlock_irq+0x23/0x50
[ 60.133861][ T49] ? lockdep_hardirqs_on+0x9c/0x150
[ 60.139129][ T49] ? __pfx_kthread+0x10/0x10
[ 60.143800][ T49] ret_from_fork+0x47c/0x820
[ 60.148417][ T49] ? __pfx_ret_from_fork+0x10/0x10
[ 60.153577][ T49] ? __switch_to_asm+0x39/0x70
[ 60.158360][ T49] ? __switch_to_asm+0x33/0x70
[ 60.163166][ T49] ? __pfx_kthread+0x10/0x10
[ 60.167813][ T49] ret_from_fork_asm+0x1a/0x30
[ 60.173078][ T49]
[ 60.176126][ T49] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 60.183491][ T49] CPU: 1 UID: 0 PID: 49 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full)
[ 60.192750][ T49] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
[ 60.202789][ T49] Workqueue: writeback wb_workfn (flush-8:0)
[ 60.208935][ T49] Call Trace:
[ 60.212198][ T49]
[ 60.215131][ T49] dump_stack_lvl+0x99/0x250
[ 60.219727][ T49] ? __asan_memcpy+0x40/0x70
[ 60.224326][ T49] ? __pfx_dump_stack_lvl+0x10/0x10
[ 60.229508][ T49] ? __pfx__printk+0x10/0x10
[ 60.234097][ T49] vpanic+0x229/0x6d0
[ 60.238077][ T49] ? __pfx_vpanic+0x10/0x10
[ 60.242565][ T49] ? is_bpf_text_address+0x292/0x2b0
[ 60.247852][ T49] ? is_bpf_text_address+0x26/0x2b0
[ 60.253052][ T49] panic+0xb9/0xc0
[ 60.256763][ T49] ? __pfx_panic+0x10/0x10
[ 60.261178][ T49] ? ret_from_fork_asm+0x1a/0x30
[ 60.266105][ T49] __warn+0x334/0x4c0
[ 60.270075][ T49] ? __folio_start_writeback+0x8e7/0xa50
[ 60.275697][ T49] ? __folio_start_writeback+0x8e7/0xa50
[ 60.281326][ T49] report_bug+0x2be/0x4f0
[ 60.285645][ T49] ? __folio_start_writeback+0x8e7/0xa50
[ 60.291267][ T49] ? __folio_start_writeback+0x8e7/0xa50
[ 60.296885][ T49] ? __folio_start_writeback+0x8e9/0xa50
[ 60.302502][ T49] handle_bug+0x84/0x160
[ 60.306738][ T49] exc_invalid_op+0x1a/0x50
[ 60.311231][ T49] asm_exc_invalid_op+0x1a/0x20
[ 60.316069][ T49] RIP: 0010:__folio_start_writeback+0x8e7/0xa50
[ 60.322389][ T49] Code: 8b 05 2d f0 ea 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 90 b5 8d 09 cc e8 1a f7 c5 ff 90 <0f> 0b 90 e9 e5 fb ff ff e8 0c f7 c5 ff 48 c7 c7 a0 03 60 8e 4c 89
[ 60.342070][ T49] RSP: 0018:ffffc90000b96ea0 EFLAGS: 00010293
[ 60.348129][ T49] RAX: ffffffff81fb1016 RBX: ffffea000094ab40 RCX: ffff888143683c00
[ 60.356106][ T49] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 60.364061][ T49] RBP: ffffc90000b97010 R08: ffffc90000b96f97 R09: 0000000000000000
[ 60.372022][ T49] R10: ffffc90000b96f80 R11: fffff52000172df3 R12: ffffea000094ab48
[ 60.380086][ T49] R13: 0000000000000000 R14: ffff88802324cd80 R15: ffff88802324cb60
[ 60.388066][ T49] ? __folio_start_writeback+0x8e6/0xa50
[ 60.393710][ T49] ? __pfx___folio_start_writeback+0x10/0x10
[ 60.399769][ T49] ? __pfx_folio_clear_dirty_for_io+0x10/0x10
[ 60.405825][ T49] ? stack_trace_save+0x9c/0xe0
[ 60.410680][ T49] __block_write_full_folio+0x75f/0xe10
[ 60.416245][ T49] ? __pfx_blkdev_get_block+0x10/0x10
[ 60.421695][ T49] blkdev_writepages+0xd1/0x170
[ 60.426536][ T49] ? __pfx_blkdev_writepages+0x10/0x10
[ 60.431999][ T49] ? __pfx_blkdev_writepages+0x10/0x10
[ 60.437445][ T49] do_writepages+0x32e/0x550
[ 60.442040][ T49] __writeback_single_inode+0x145/0xff0
[ 60.447662][ T49] ? wbc_attach_and_unlock_inode+0x3f0/0x5d0
[ 60.453639][ T49] writeback_sb_inodes+0x6c7/0x1010
[ 60.458846][ T49] ? __pfx_writeback_sb_inodes+0x10/0x10
[ 60.464585][ T49] ? __pfx_down_read_trylock+0x10/0x10
[ 60.470040][ T49] ? __pfx___up_read+0x10/0x10
[ 60.474802][ T49] __writeback_inodes_wb+0x111/0x240
[ 60.480090][ T49] wb_writeback+0x44f/0xaf0
[ 60.484589][ T49] ? queue_io+0x331/0x590
[ 60.488909][ T49] ? __pfx_wb_writeback+0x10/0x10
[ 60.493946][ T49] wb_workfn+0xaef/0xef0
[ 60.498189][ T49] ? __pfx_wb_workfn+0x10/0x10
[ 60.502940][ T49] ? __lock_acquire+0xab9/0xd20
[ 60.507788][ T49] ? process_scheduled_works+0x9ef/0x17b0
[ 60.513500][ T49] ? _raw_spin_unlock_irq+0x23/0x50
[ 60.518779][ T49] ? process_scheduled_works+0x9ef/0x17b0
[ 60.524499][ T49] ? process_scheduled_works+0x9ef/0x17b0
[ 60.530218][ T49] process_scheduled_works+0xade/0x17b0
[ 60.535774][ T49] ? __pfx_process_scheduled_works+0x10/0x10
[ 60.541765][ T49] worker_thread+0x8a0/0xda0
[ 60.546383][ T49] kthread+0x70e/0x8a0
[ 60.550472][ T49] ? __pfx_worker_thread+0x10/0x10
[ 60.555591][ T49] ? __pfx_kthread+0x10/0x10
[ 60.560185][ T49] ? _raw_spin_unlock_irq+0x23/0x50
[ 60.565376][ T49] ? lockdep_hardirqs_on+0x9c/0x150
[ 60.570559][ T49] ? __pfx_kthread+0x10/0x10
[ 60.575150][ T49] ret_from_fork+0x47c/0x820
[ 60.579737][ T49] ? __pfx_ret_from_fork+0x10/0x10
[ 60.584842][ T49] ? __switch_to_asm+0x39/0x70
[ 60.589596][ T49] ? __switch_to_asm+0x33/0x70
[ 60.594434][ T49] ? __pfx_kthread+0x10/0x10
[ 60.599023][ T49] ret_from_fork_asm+0x1a/0x30
[ 60.603787][ T49]
[ 60.607080][ T49] Kernel Offset: disabled
[ 60.611397][ T49] Rebooting in 86400 seconds..