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+0x6f/0xc0 lib/string.c:283
Read of size 1 at addr ffff88803b0c78a6 by task syz.7.538/8272

CPU: 0 UID: 0 PID: 8272 Comm: syz.7.538 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 strcmp+0x6f/0xc0 lib/string.c:283
 hpfs_get_ea+0x114/0xdb0 fs/hpfs/ea.c:139
 hpfs_read_inode+0x19d/0x1010 fs/hpfs/inode.c:63
 hpfs_fill_super+0x129d/0x2040 fs/hpfs/super.c:654
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
 vfs_get_tree+0x92/0x2b0 fs/super.c:1751
 fc_mount fs/namespace.c:1274 [inline]
 do_new_mount_fc fs/namespace.c:3726 [inline]
 do_new_mount+0x302/0xa10 fs/namespace.c:3802
 do_mount fs/namespace.c:4125 [inline]
 __do_sys_mount fs/namespace.c:4324 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4301
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9c6b19034a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9c6c057e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f9c6c057ef0 RCX: 00007f9c6b19034a
RDX: 000020000000a000 RSI: 0000200000009ec0 RDI: 00007f9c6c057eb0
RBP: 000020000000a000 R08: 00007f9c6c057ef0 R09: 0000000003200041
R10: 0000000003200041 R11: 0000000000000246 R12: 0000200000009ec0
R13: 00007f9c6c057eb0 R14: 0000000000009e15 R15: 0000200000000140
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x1d57 pfn:0x3b0c7
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000001d57 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 7589, tgid 7589 (syz.6.372), ts 245644055095, free_ts 256413622130
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3869
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5159
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2435
 shmem_alloc_folio mm/shmem.c:1884 [inline]
 shmem_alloc_and_add_folio+0x4ba/0x10f0 mm/shmem.c:1923
 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2547
 shmem_get_folio mm/shmem.c:2653 [inline]
 shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3303
 generic_perform_write+0x2c5/0x900 mm/filemap.c:4209
 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3478
 __kernel_write_iter+0x428/0x910 fs/read_write.c:619
 dump_emit_page fs/coredump.c:1298 [inline]
 dump_user_range+0x8a0/0xc90 fs/coredump.c:1372
 elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111
 coredump_write+0x116c/0x1900 fs/coredump.c:1049
 vfs_coredump+0x1db5/0x2a60 fs/coredump.c:1170
 get_signal+0x1109/0x1340 kernel/signal.c:3019
page last free pid 7589 tgid 7589 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:2963
 folios_put_refs+0x584/0x670 mm/swap.c:1002
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1120
 shmem_truncate_range mm/shmem.c:1232 [inline]
 shmem_evict_inode+0x272/0xa70 mm/shmem.c:1360
 evict+0x504/0x9c0 fs/inode.c:810
 __dentry_kill+0x209/0x660 fs/dcache.c:669
 dput+0x19f/0x2b0 fs/dcache.c:911
 __fput+0x68e/0xa70 fs/file_table.c:476
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x6b5/0x2300 kernel/exit.c:966
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
 get_signal+0x1286/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:73
 exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

Memory state around the buggy address:
 ffff88803b0c7780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88803b0c7800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88803b0c7880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88803b0c7900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88803b0c7980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================