loop0: detected capacity change from 0 to 32768
=======================================================
WARNING: The mand mount option has been deprecated and
         and is ignored by this kernel. Remove the mand
         option from the mount to silence this warning.
=======================================================
JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
sr 2:0:0:0: [sr0] CDROM not ready.  Make sure there is a disc in the drive.
(syz.0.0,5322,0):ocfs2_check_set_options:1244 ERROR: Invalid heartbeat mount options
loop0: detected capacity change from 32768 to 32767
OCFS2: ERROR (device loop0): int ocfs2_validate_dx_root(struct super_block *, struct buffer_head *): Dir Index Root # 90847148244992 has bad signature 
On-disk corruption discovered. Please run fsck.ocfs2 once the filesystem is unmounted.
OCFS2: File system is now read-only.
(syz.0.0,5322,0):ocfs2_find_entry_dx:1037 ERROR: status = -30
==================================================================
BUG: KASAN: use-after-free in ocfs2_dx_dir_lookup_rec+0x1eb/0x7f0 fs/ocfs2/dir.c:813
Read of size 4 at addr ffff88805311dda0 by task syz.0.0/5322

CPU: 0 UID: 0 PID: 5322 Comm: syz.0.0 Not tainted syzkaller #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
 ocfs2_dx_dir_lookup_rec+0x1eb/0x7f0 fs/ocfs2/dir.c:813
 ocfs2_dx_dir_lookup+0xdb/0x520 fs/ocfs2/dir.c:868
 ocfs2_dx_dir_search fs/ocfs2/dir.c:928 [inline]
 ocfs2_find_entry_dx fs/ocfs2/dir.c:1042 [inline]
 ocfs2_find_entry+0x1004/0x2000 fs/ocfs2/dir.c:1079
 ocfs2_check_dir_for_entry+0x14c/0x3f0 fs/ocfs2/dir.c:2048
 ocfs2_mknod+0x697/0x2050 fs/ocfs2/namei.c:291
 ocfs2_create+0x1a5/0x440 fs/ocfs2/namei.c:676
 lookup_open fs/namei.c:3796 [inline]
 open_last_lookups fs/namei.c:3895 [inline]
 path_openat+0x14f1/0x3830 fs/namei.c:4131
 do_filp_open+0x1fa/0x410 fs/namei.c:4161
 do_sys_openat2+0x121/0x1c0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1463
 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: 0033:0x7f18fff8eec9
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:00007f1900e28038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f19001e5fa0 RCX: 00007f18fff8eec9
RDX: 0000000000105042 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007f1900011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000001ff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f19001e6038 R14: 00007f19001e5fa0 R15: 00007ffd9e9e66f8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5311d
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea00014c4748 ffffea00014c4748 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffff88805311dc80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805311dd00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88805311dd80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88805311de00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805311de80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================