OCFS2: ERROR (device loop0): int ocfs2_validate_dx_root(struct super_block *, struct buffer_head *): Dir Index Root # 37 has bad signature XDIR01
On-disk corruption discovered. Please run fsck.ocfs2 once the filesystem is unmounted.
OCFS2: File system is now read-only.
(syz.0.0,5320,0):ocfs2_find_entry_dx:1029 ERROR: status = -30
==================================================================
BUG: KASAN: use-after-free in ocfs2_dx_dir_lookup_rec+0x206/0x810 fs/ocfs2/dir.c:805
Read of size 4 at addr ffff88805459d2c0 by task syz.0.0/5320

CPU: 0 UID: 0 PID: 5320 Comm: syz.0.0 Not tainted 6.13.0-syzkaller-05182-ge0b1f5914274 #0
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 lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:489
 kasan_report+0x143/0x180 mm/kasan/report.c:602
 ocfs2_dx_dir_lookup_rec+0x206/0x810 fs/ocfs2/dir.c:805
 ocfs2_dx_dir_lookup+0x163/0x930 fs/ocfs2/dir.c:860
 ocfs2_dx_dir_search fs/ocfs2/dir.c:920 [inline]
 ocfs2_find_entry_dx fs/ocfs2/dir.c:1034 [inline]
 ocfs2_find_entry+0x1309/0x2570 fs/ocfs2/dir.c:1071
 ocfs2_check_dir_for_entry+0x17b/0x4a0 fs/ocfs2/dir.c:2040
 ocfs2_mknod+0x83c/0x2b30 fs/ocfs2/namei.c:288
 ocfs2_create+0x1ab/0x470 fs/ocfs2/namei.c:674
 lookup_open fs/namei.c:3649 [inline]
 open_last_lookups fs/namei.c:3748 [inline]
 path_openat+0x192f/0x3580 fs/namei.c:3984
 do_filp_open+0x27f/0x4e0 fs/namei.c:4014
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1427
 do_sys_open fs/open.c:1442 [inline]
 __do_sys_creat fs/open.c:1520 [inline]
 __se_sys_creat fs/open.c:1514 [inline]
 __x64_sys_creat+0x123/0x170 fs/open.c:1514
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd1ccb8cd29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fd1cd9ca038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007fd1ccda6080 RCX: 00007fd1ccb8cd29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040
RBP: 00007fd1ccc0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fd1ccda6080 R15: 00007ffe1160a198
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x53 pfn:0x5459d
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea0001516788 ffffea0001516708 0000000000000000
raw: 0000000000000053 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 0x148c48(GFP_NOFS|__GFP_NOFAIL|__GFP_COMP|__GFP_HARDWALL|__GFP_MOVABLE), pid 5323, tgid 5323 (jbd2/loop0-75), ts 76114467935, free_ts 76122245935
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558
 prep_new_page mm/page_alloc.c:1566 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3476
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753
 alloc_pages_mpol_noprof+0x3e1/0x780 mm/mempolicy.c:2269
 alloc_pages_noprof mm/mempolicy.c:2349 [inline]
 folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2356
 filemap_alloc_folio_noprof+0xe1/0x540 mm/filemap.c:1001
 __filemap_get_folio+0x41f/0x940 mm/filemap.c:1943
 grow_dev_folio fs/buffer.c:1039 [inline]
 grow_buffers fs/buffer.c:1105 [inline]
 __getblk_slow fs/buffer.c:1131 [inline]
 bdev_getblk+0x1d4/0x670 fs/buffer.c:1431
 __getblk include/linux/buffer_head.h:380 [inline]
 jbd2_journal_get_descriptor_buffer+0x1c3/0x4e0 fs/jbd2/journal.c:968
 journal_submit_commit_record+0x104/0x920 fs/jbd2/commit.c:129
 jbd2_journal_commit_transaction+0x3851/0x61b0 fs/jbd2/commit.c:877
 kjournald2+0x41c/0x7b0 fs/jbd2/journal.c:201
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page last free pid 5319 tgid 5318 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_folios+0xe39/0x18b0 mm/page_alloc.c:2706
 folios_put_refs+0x76c/0x860 mm/swap.c:962
 folio_batch_release include/linux/pagevec.h:101 [inline]
 mapping_try_invalidate+0x3f7/0x550 mm/truncate.c:501
 loop_set_status+0x1cc/0x940 drivers/block/loop.c:1271
 lo_ioctl+0xcd3/0x23b0
 blkdev_ioctl+0x57d/0x6a0 block/ioctl.c:693
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88805459d180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805459d200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88805459d280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff88805459d300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805459d380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================