hpfs: filesystem error: invalid number of hotfixes: 2066844986, used: 2066844985; already mounted read-only
hpfs: filesystem error: improperly stopped
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:265
Read of size 1 at addr ffff8880662358a6 by task syz.4.51/6131

CPU: 0 UID: 0 PID: 6131 Comm: syz.4.51 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
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+0x127b/0x1fb0 fs/hpfs/super.c:652
 get_tree_bdev_flags+0x436/0x500 fs/super.c:1821
 vfs_get_tree+0x92/0x2a0 fs/super.c:1881
 fc_mount fs/namespace.c:1282 [inline]
 do_new_mount_fc fs/namespace.c:3910 [inline]
 do_new_mount+0x325/0xb00 fs/namespace.c:3986
 do_mount fs/namespace.c:4350 [inline]
 __do_sys_mount fs/namespace.c:4565 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4542
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x00007fa2f9da0d8a
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:00007fa2fac87e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fa2fac87ee0 RCX: 00007fa2f9da0d8a
RDX: 0000200000000000 RSI: 0000200000000080 RDI: 00007fa2fac87ea0
RBP: 0000200000000000 R08: 00007fa2fac87ee0 R09: 0000000003200041
R10: 0000000003200041 R11: 0000000000000246 R12: 0000200000000080
R13: 00007fa2fac87ea0 R14: 0000000000009e15 R15: 0000200000009fc0
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x906 pfn:0x66235
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea000198a988 ffffea0001988d88 0000000000000000
raw: 0000000000000906 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 6122, tgid 6122 (syz.0.50), ts 104703356653
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1874
 prep_new_page+0x22/0xb0 mm/page_alloc.c:1882
 get_page_from_freelist+0x22a1/0x22e0 mm/page_alloc.c:3964
 __alloc_frozen_pages_noprof+0x211/0x450 mm/page_alloc.c:5506
 alloc_pages_mpol+0x21e/0x390 mm/mempolicy.c:2520
 folio_alloc_mpol_noprof+0x39/0x160 mm/mempolicy.c:2539
 shmem_alloc_folio mm/shmem.c:2184 [inline]
 shmem_alloc_and_add_folio+0x43e/0xf60 mm/shmem.c:2226
 shmem_get_folio_gfp+0x594/0x1330 mm/shmem.c:2792
 shmem_get_folio mm/shmem.c:2891 [inline]
 shmem_write_begin+0x16c/0x330 mm/shmem.c:3526
 generic_perform_write+0x2d5/0x8e0 mm/filemap.c:4399
 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3701
 __kernel_write_iter+0x44a/0x8f0 fs/read_write.c:621
 dump_write_iter fs/coredump.c:1360 [inline]
 dump_emit_page fs/coredump.c:1533 [inline]
 dump_user_range+0x715/0xca0 fs/coredump.c:1601
 elf_core_dump+0x346a/0x3a70 fs/binfmt_elf.c:2106
 coredump_write fs/coredump.c:1150 [inline]
 do_coredump+0x5ed1/0x6a60 fs/coredump.c:1237
 vfs_coredump+0xac3/0x10c0 fs/coredump.c:1312
page last free pid 5646 tgid 5646 ts 105643156515 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1416 [inline]
 free_unref_folios+0xdcc/0x15d0 mm/page_alloc.c:3032
 folios_put_refs+0x5b6/0x6d0 mm/folio.c:1100
 folio_batch_release include/linux/folio_batch.h:101 [inline]
 shmem_undo_range+0x55a/0x1730 mm/shmem.c:1377
 shmem_truncate_range mm/shmem.c:1513 [inline]
 shmem_evict_inode+0x240/0xb00 mm/shmem.c:1657
 evict+0x624/0xb50 fs/inode.c:822
 filename_unlinkat+0x2f7/0x5c0 fs/namei.c:5741
 __do_sys_unlink fs/namei.c:5772 [inline]
 __se_sys_unlink+0x2e/0x140 fs/namei.c:5769
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888066235780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888066235800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888066235880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff888066235900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888066235980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================