loop3: detected capacity change from 0 to 128
hpfs: filesystem error: invalid number of hotfixes: 2066844986, used: 2066844985; going on - but anything won't be destroyed because it's read-only
hpfs: filesystem error: improperly stopped
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
==================================================================
BUG: KASAN: use-after-free in strcmp+0x6b/0xc0 lib/string.c:265
Read of size 1 at addr ffff88804ee8c8a6 by task syz.3.3095/13025

CPU: 0 UID: 0 PID: 13025 
CPU: 0 UID: 0 PID: 13025 Comm: syz.3.3095 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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:1887
 vfs_get_tree+0x92/0x2a0 fs/super.c:1947
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3772 [inline]
 do_new_mount+0x319/0xdc0 fs/namespace.c:3848
 do_mount fs/namespace.c:4181 [inline]
 __do_sys_mount fs/namespace.c:4397 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f091a59f34a
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:00007f091b49ee58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f091b49eee0 RCX: 00007f091a59f34a
RDX: 0000200000000000 RSI: 0000200000000040 RDI: 00007f091b49eea0
RBP: 0000200000000000 R08: 00007f091b49eee0 R09: 0000000003200041
R10: 0000000003200041 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f091b49eea0 R14: 0000000000009e30 R15: 0000200000000080
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x156b pfn:0x4ee8c
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00013ba2c8 ffffea00013ba348 0000000000000000
raw: 000000000000156b 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 12929, tgid 12927 (syz.1.3056), ts 392351913612
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436
 alloc_pages_mpol+0x21e/0x390 mm/mempolicy.c:2486
 folio_alloc_mpol_noprof+0x39/0x160 mm/mempolicy.c:2505
 shmem_alloc_folio mm/shmem.c:1933 [inline]
 shmem_alloc_and_add_folio+0x43e/0xf60 mm/shmem.c:1975
 shmem_get_folio_gfp+0x5da/0x16d0 mm/shmem.c:2528
 shmem_get_folio mm/shmem.c:2634 [inline]
 shmem_write_begin+0x16c/0x330 mm/shmem.c:3265
 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4374
 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3440
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5620 tgid 5620 ts 393779882752 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 free_unref_folios+0xdc2/0x14e0 mm/page_alloc.c:3022
 folios_put_refs+0x9e9/0xb30 mm/folio.c:1034
 folio_batch_release include/linux/folio_batch.h:101 [inline]
 shmem_undo_range+0x4e6/0x15d0 mm/shmem.c:1161
 shmem_truncate_range mm/shmem.c:1289 [inline]
 shmem_evict_inode+0x247/0xae0 mm/shmem.c:1420
 evict+0x624/0xb50 fs/inode.c:822
 dentry_kill+0x1b9/0x880 fs/dcache.c:826
 finish_dput+0x1a/0x260 fs/dcache.c:1001
 __fput+0x675/0xa50 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+0x204/0x770 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:336 [inline]
 do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88804ee8c780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804ee8c800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88804ee8c880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88804ee8c900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804ee8c980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================