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 ffff88804387a8a6 by task syz.0.18/5873

CPU: 0 UID: 0 PID: 5873 Comm: syz.0.18 Not tainted 6.17.0-rc1-syzkaller-g8f5ae30d69d7 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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:1692
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805
 do_mount fs/namespace.c:4133 [inline]
 __do_sys_mount fs/namespace.c:4344 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4321
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2efc7900ca
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:00007f2efd68fe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f2efd68fef0 RCX: 00007f2efc7900ca
RDX: 0000200000009e80 RSI: 0000200000009ec0 RDI: 00007f2efd68feb0
RBP: 0000200000009e80 R08: 00007f2efd68fef0 R09: 0000000000000041
R10: 0000000000000041 R11: 0000000000000246 R12: 0000200000009ec0
R13: 00007f2efd68feb0 R14: 0000000000009e02 R15: 0000200000009fc0
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4387a
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea00010e1ec8 ffffea00010e1e48 0000000000000000
raw: 0000000000000000 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 4754, tgid 4754 (udevd), ts 47514087830, free_ts 141029462822
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 compaction_alloc_noprof mm/compaction.c:1836 [inline]
 compaction_alloc+0x3099/0x34a0 mm/compaction.c:1847
 migrate_folio_unmap mm/migrate.c:1189 [inline]
 migrate_pages_batch+0x81e/0x3620 mm/migrate.c:1851
 migrate_pages_sync mm/migrate.c:1974 [inline]
 migrate_pages+0x1bcc/0x2930 mm/migrate.c:2083
 compact_zone+0x23e1/0x4ab0 mm/compaction.c:2647
 compact_node+0x1d2/0x280 mm/compaction.c:2916
 kcompactd+0xbc8/0x1290 mm/compaction.c:3214
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page last free pid 30 tgid 30 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
 __folio_put+0x21b/0x2c0 mm/swap.c:112
 migrate_folio_move mm/migrate.c:1387 [inline]
 migrate_folios_move mm/migrate.c:1697 [inline]
 migrate_pages_batch+0x234a/0x3620 mm/migrate.c:1944
 migrate_pages_sync mm/migrate.c:1974 [inline]
 migrate_pages+0x1bcc/0x2930 mm/migrate.c:2083
 compact_zone+0x23e1/0x4ab0 mm/compaction.c:2647
 compact_node+0x1d2/0x280 mm/compaction.c:2916
 kcompactd+0xbc8/0x1290 mm/compaction.c:3214
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88804387a780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804387a800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88804387a880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88804387a900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804387a980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================