ocfs2: Slot 0 on device (7,0) was already allocated to this node!
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+0xb28/0x3b9c fs/ocfs2/suballoc.c:834
Read of size 4 at addr ffff000100bfa004 by task syz.0.574/8808

CPU: 0 UID: 0 PID: 8808 Comm: syz.0.574 Not tainted 6.16.0-rc6-syzkaller-gaaef6f251176 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 print_address_description+0xa8/0x220 mm/kasan/report.c:378
 print_report+0x68/0x84 mm/kasan/report.c:480
 kasan_report+0xb0/0x110 mm/kasan/report.c:593
 __asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380
 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+0xb28/0x3b9c fs/ocfs2/suballoc.c:834
 ocfs2_reserve_new_metadata_blocks+0x368/0x810 fs/ocfs2/suballoc.c:984
 ocfs2_mknod+0xbd8/0x1cf0 fs/ocfs2/namei.c:347
 ocfs2_create+0x190/0x474 fs/ocfs2/namei.c:673
 lookup_open fs/namei.c:3717 [inline]
 open_last_lookups fs/namei.c:3816 [inline]
 path_openat+0x12d8/0x2c40 fs/namei.c:4052
 do_filp_open+0x18c/0x36c fs/namei.c:4082
 do_sys_openat2+0x11c/0x1b4 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]
 __arm64_sys_openat+0x120/0x158 fs/open.c:1463
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x61e pfn:0x140bfa
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffdffc3912148 fffffdffc402fec8 0000000000000000
raw: 000000000000061e 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff000100bf9f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff000100bf9f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff000100bfa000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff000100bfa080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff000100bfa100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
ocfs2: Unmounting device (7,0) on (node local)