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.
==================================================================
BUG: KASAN: use-after-free in ocfs2_find_smallest_chain fs/ocfs2/suballoc.c:413 [inline]
BUG: KASAN: use-after-free in ocfs2_block_group_alloc_contig fs/ocfs2/suballoc.c:430 [inline]
BUG: KASAN: use-after-free in ocfs2_block_group_alloc fs/ocfs2/suballoc.c:699 [inline]
BUG: KASAN: use-after-free in ocfs2_reserve_suballoc_bits+0xdd0/0x4640 fs/ocfs2/suballoc.c:834
Read of size 4 at addr ffff888053d74004 by task syz.0.0/5355

CPU: 0 UID: 0 PID: 5355 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_find_smallest_chain fs/ocfs2/suballoc.c:413 [inline]
 ocfs2_block_group_alloc_contig fs/ocfs2/suballoc.c:430 [inline]
 ocfs2_block_group_alloc fs/ocfs2/suballoc.c:699 [inline]
 ocfs2_reserve_suballoc_bits+0xdd0/0x4640 fs/ocfs2/suballoc.c:834
 ocfs2_reserve_new_metadata_blocks+0x403/0x940 fs/ocfs2/suballoc.c:984
 ocfs2_create_refcount_tree+0x284/0x1250 fs/ocfs2/refcounttree.c:571
 ocfs2_reflink_remap_blocks+0x2ea/0x1930 fs/ocfs2/refcounttree.c:4646
 ocfs2_remap_file_range+0x4b7/0x730 fs/ocfs2/file.c:2740
 vfs_clone_file_range+0x42c/0x7a0 fs/remap_range.c:403
 ioctl_file_clone fs/ioctl.c:240 [inline]
 ioctl_file_clone_range fs/ioctl.c:258 [inline]
 do_vfs_ioctl+0xd2b/0x1430 fs/ioctl.c:545
 __do_sys_ioctl fs/ioctl.c:596 [inline]
 __se_sys_ioctl+0x82/0x170 fs/ioctl.c:584
 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: 0033:0x7ff6dd98ebe9
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:00007ff6de84f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff6ddbb5fa0 RCX: 00007ff6dd98ebe9
RDX: 00002000000000c0 RSI: 000000004020940d RDI: 0000000000000006
RBP: 00007ff6dda11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff6ddbb6038 R14: 00007ff6ddbb5fa0 R15: 00007ffdfe16e1b8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x53d74
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea00014f5d48 ffffea00014f4cc8 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:
 ffff888053d73f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888053d73f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888053d74000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888053d74080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888053d74100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================