hpfs: filesystem error: warning: spare dnodes used, try chkdsk
hpfs: You really don't want any checks? You are crazy...
hpfs: hpfs_map_sector(): read error
hpfs: code page support is disabled
==================================================================
BUG: KASAN: use-after-free in strcmp+0x6b/0xc0 lib/string.c:283
Read of size 1 at addr ffff8880895ec8a6 by task syz.0.449/10141

CPU: 1 UID: 0 PID: 10141 Comm: syz.0.449 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 strcmp+0x6b/0xc0 lib/string.c:283
 hpfs_get_ea+0x134/0xee0 fs/hpfs/ea.c:139
 hpfs_read_inode+0x1a6/0x1050 fs/hpfs/inode.c:63
 hpfs_fill_super+0x123d/0x1fa0 fs/hpfs/super.c:651
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1691
 vfs_get_tree+0x92/0x2a0 fs/super.c:1751
 fc_mount fs/namespace.c:1199 [inline]
 do_new_mount_fc fs/namespace.c:3636 [inline]
 do_new_mount+0x329/0xa50 fs/namespace.c:3712
 do_mount fs/namespace.c:4035 [inline]
 __do_sys_mount fs/namespace.c:4224 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4201
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe588b7bf4a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe586dd5e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe586dd5ee0 RCX: 00007fe588b7bf4a
RDX: 000020000000a000 RSI: 0000200000009ec0 RDI: 00007fe586dd5ea0
RBP: 000020000000a000 R08: 00007fe586dd5ee0 R09: 0000000003a00041
R10: 0000000003a00041 R11: 0000000000000246 R12: 0000200000009ec0
R13: 00007fe586dd5ea0 R14: 0000000000009e22 R15: 0000200000000000
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x7fe57eb2c pfn:0x895ec
flags: 0x80000000000000(node=0|zone=1)
raw: 0080000000000000 ffffea0002257b48 ffffea0002257ac8 0000000000000000
raw: 00000007fe57eb2c 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO|__GFP_COMP), pid 10137, tgid 10136 (syz.0.448), ts 648657887957, free_ts 649211041639
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884
 prep_new_page mm/page_alloc.c:1892 [inline]
 get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3945
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5240
 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2486
 folio_alloc_mpol_noprof mm/mempolicy.c:2505 [inline]
 vma_alloc_folio_noprof+0xea/0x290 mm/mempolicy.c:2540
 folio_prealloc+0x30/0x170 mm/memory.c:-1
 alloc_anon_folio mm/memory.c:5168 [inline]
 do_anonymous_page mm/memory.c:5225 [inline]
 do_pte_missing+0x86a/0x27a0 mm/memory.c:4402
 handle_pte_fault mm/memory.c:6276 [inline]
 __handle_mm_fault mm/memory.c:6414 [inline]
 handle_mm_fault+0xd0a/0x13c0 mm/memory.c:6583
 do_user_addr_fault+0xa73/0x1360 arch/x86/mm/fault.c:1334
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
page last free pid 5952 tgid 5952 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1433 [inline]
 free_unref_folios+0xc13/0x17f0 mm/page_alloc.c:3030
 folios_put_refs+0x56f/0x680 mm/swap.c:1002
 folios_put include/linux/mm.h:1675 [inline]
 folio_batch_move_lru+0x2a6/0x340 mm/swap.c:179
 lru_add_drain_cpu+0xb4/0x770 mm/swap.c:648
 lru_add_and_bh_lrus_drain mm/swap.c:751 [inline]
 lru_add_drain_per_cpu+0x142/0x400 mm/swap.c:772
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
 worker_thread+0x89f/0xd90 kernel/workqueue.c:3421
 kthread+0x726/0x8b0 kernel/kthread.c:463
 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Memory state around the buggy address:
 ffff8880895ec780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880895ec800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880895ec880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff8880895ec900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880895ec980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================