hpfs: filesystem error: warning: spare dnodes used, try chkdsk
hpfs: Proceeding, but your filesystem could be corrupted if you delete files or directories
hpfs: You really don't want any checks? You are crazy...
hpfs: hpfs_map_sector(): read error
hpfs: code page support is disabled
=========[  172.014882][ T6782] ==================================================================
BUG: KASAN: use-after-free in strcmp+0x6b/0xc0 lib/string.c:265
Read of size 1 at addr ffff88804b7948a6 by task syz.0.143/6782

CPU: 1 UID: 0 PID: 6782 Comm: syz.0.143 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 strcmp+0x6b/0xc0 lib/string.c:265
 hpfs_get_ea+0x137/0xeb0 fs/hpfs/ea.c:139
 hpfs_read_inode+0x1a9/0x1060 fs/hpfs/inode.c:63
 hpfs_fill_super+0x1275/0x1fa0 fs/hpfs/super.c:652
 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1634
 vfs_get_tree+0x92/0x2a0 fs/super.c:1694
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3765 [inline]
 do_new_mount+0x319/0xdc0 fs/namespace.c:3841
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4367
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f515eb5f0ca
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:00007f515cdb5e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f515cdb5ee0 RCX: 00007f515eb5f0ca
RDX: 000020000000a000 RSI: 0000200000009ec0 RDI: 00007f515cdb5ea0
RBP: 000020000000a000 R08: 00007f515cdb5ee0 R09: 0000000003200041
R10: 0000000003200041 R11: 0000000000000246 R12: 0000200000009ec0
R13: 00007f515cdb5ea0 R14: 0000000000009e28 R15: 0000200000000000
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x85c pfn:0x4b794
flags: 0x80000000000000(node=0|zone=1)
page_type: f0(buddy)
raw: 0080000000000000 ffffea00019d6908 ffffea000130da08 0000000000000000
raw: 000000000000085c 0000000000000002 00000000f0000000 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 6699, tgid 6698 (syz.3.129), ts 166259540590, free_ts 171736325621
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x262a/0x26a0 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304
 alloc_pages_mpol+0xce/0x280 mm/mempolicy.c:2490
 folio_alloc_mpol_noprof+0x3b/0x1e0 mm/mempolicy.c:2509
 shmem_alloc_folio mm/shmem.c:1907 [inline]
 shmem_alloc_and_add_folio mm/shmem.c:1949 [inline]
 shmem_get_folio_gfp+0x6ee/0x1c40 mm/shmem.c:2502
 shmem_get_folio mm/shmem.c:2608 [inline]
 shmem_write_begin+0x166/0x320 mm/shmem.c:3239
 generic_perform_write+0x2ad/0x8b0 mm/filemap.c:4358
 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3414
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x61e/0xbb0 fs/read_write.c:687
 ksys_write+0x156/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5599 tgid 5599 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 free_unref_folios+0xcd4/0x1910 mm/page_alloc.c:3011
 folios_put_refs+0x815/0x920 mm/swap.c:1057
 folio_batch_release include/linux/folio_batch.h:101 [inline]
 shmem_undo_range+0x4e6/0x15d0 mm/shmem.c:1149
 shmem_truncate_range mm/shmem.c:1277 [inline]
 shmem_evict_inode+0x280/0xa80 mm/shmem.c:1407
 evict+0x624/0xb50 fs/inode.c:825
 dentry_kill+0x1b9/0x880 fs/dcache.c:826
 finish_dput+0x1a/0x260 fs/dcache.c:1001
 __fput+0x699/0xa80 fs/file_table.c:520
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88804b794780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804b794800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88804b794880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88804b794900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804b794980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================