loop7: detected capacity change from 0 to 128
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 ffff88804befd8a6 by task syz.7.681/12576

CPU: 1 UID: 0 PID: 12576 Comm: syz.7.681 Not tainted syzkaller #0 PREEMPT_{RT,(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: 0033:0x7fbd35d6f34a
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:00007fbd33fc5e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fbd33fc5ee0 RCX: 00007fbd35d6f34a
RDX: 0000200000000100 RSI: 0000200000000040 RDI: 00007fbd33fc5ea0
RBP: 0000200000000100 R08: 00007fbd33fc5ee0 R09: 0000000003200041
R10: 0000000003200041 R11: 0000000000000246 R12: 0000200000000040
R13: 00007fbd33fc5ea0 R14: 0000000000009e15 R15: 0000200000000000
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x230d pfn:0x4befd
flags: 0x80000000000000(node=0|zone=1)
raw: 0080000000000000 dead000000000100 dead000000000122 0000000000000000
raw: 000000000000230d 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 0x152c4a(GFP_NOFS|__GFP_HIGHMEM|__GFP_MOVABLE|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 11816, tgid 11815 (syz.5.649), ts 727241970993
 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+0x2591/0x2600 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x230/0x5c0 mm/page_alloc.c:5436
 alloc_pages_mpol+0xd4/0x280 mm/mempolicy.c:2495
 alloc_frozen_pages_noprof mm/mempolicy.c:2566 [inline]
 alloc_pages_noprof+0xd2/0x2f0 mm/mempolicy.c:2586
 folio_alloc_noprof+0x22/0xc0 mm/mempolicy.c:2596
 filemap_alloc_folio_noprof+0x111/0x4c0 mm/filemap.c:1019
 ractl_alloc_folio mm/readahead.c:200 [inline]
 page_cache_ra_unbounded+0x2d6/0x8f0 mm/readahead.c:288
 do_page_cache_ra mm/readahead.c:348 [inline]
 page_cache_ra_order+0x2c1/0x4a0 mm/readahead.c:558
 filemap_readahead mm/filemap.c:2682 [inline]
 filemap_get_pages+0x83b/0x1e80 mm/filemap.c:2728
 filemap_read+0x429/0x11e0 mm/filemap.c:2824
 ext4_file_read_iter+0x568/0xaf0 fs/ext4/file.c:-1
 __kernel_read+0x4d3/0x970 fs/read_write.c:532
 integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28
 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline]
 ima_calc_file_hash+0x45d/0x8a0 security/integrity/ima/ima_crypto.c:280
 ima_collect_measurement+0x521/0xa10 security/integrity/ima/ima_api.c:300
page last free pid 10830 tgid 10830 ts 733331071212 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 free_unref_folios+0xd0f/0x1950 mm/page_alloc.c:3022
 folios_put_refs+0x815/0x920 mm/folio.c:1055
 folio_batch_release include/linux/folio_batch.h:101 [inline]
 truncate_inode_pages_range+0x3cd/0xd80 mm/truncate.c:408
 ext4_evict_inode+0x247/0xfe0 fs/ext4/inode.c:198
 evict+0x624/0xb50 fs/inode.c:822
 dispose_list fs/inode.c:864 [inline]
 evict_inodes+0x7e3/0x870 fs/inode.c:918
 generic_shutdown_super+0xaa/0x2d0 fs/super.c:755
 kill_block_super+0x44/0xa0 fs/super.c:1918
 ext4_kill_sb+0x68/0xb0 fs/ext4/super.c:7527
 deactivate_locked_super+0xbc/0x110 fs/super.c:603
 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x73a/0x2360 kernel/exit.c:1008
 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151
 __do_sys_exit_group kernel/exit.c:1162 [inline]
 __se_sys_exit_group kernel/exit.c:1160 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1160
 x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232

Memory state around the buggy address:
 ffff88804befd780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804befd800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88804befd880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88804befd900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804befd980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================