loop0: detected capacity change from 0 to 32768
BTRFS: device fsid c9fe44da-de57-406a-8241-57ec7d4412cf devid 1 transid 8 /dev/loop0 (7:0) scanned by syz.0.0 (5338)
BTRFS info (device loop0): first mount of filesystem c9fe44da-de57-406a-8241-57ec7d4412cf
BTRFS info (device loop0): using crc32c (crc32c-lib) checksum algorithm
BTRFS error (device loop0): ignoresuperflags must be used with ro mount option
BTRFS error (device loop0): open_ctree failed: -22
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.
=======================================================
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 ffff88804c385004 by task syz.0.0/5338

CPU: 0 UID: 0 PID: 5338 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_reserve_new_metadata fs/ocfs2/suballoc.c:1027 [inline]
 ocfs2_lock_allocators+0x29e/0x5c0 fs/ocfs2/suballoc.c:2761
 ocfs2_extend_allocation+0x39b/0x17a0 fs/ocfs2/file.c:589
 ocfs2_allocate_unwritten_extents+0x2e9/0x7b0 fs/ocfs2/file.c:1496
 __ocfs2_change_file_space+0x901/0xe80 fs/ocfs2/file.c:2023
 ocfs2_fallocate+0x1f5/0x240 fs/ocfs2/file.c:2138
 vfs_fallocate+0x666/0x7e0 fs/open.c:342
 ksys_fallocate fs/open.c:366 [inline]
 __do_sys_fallocate fs/open.c:371 [inline]
 __se_sys_fallocate fs/open.c:369 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:369
 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: 0033:0x7f090c18eec9
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:00007f090cf58038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f090c3e5fa0 RCX: 00007f090c18eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f090c211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000001001f0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f090c3e6038 R14: 00007f090c3e5fa0 R15: 00007fff5b303858
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x7ffffffdc pfn:0x4c385
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea000130e548 ffffea00013346c8 0000000000000000
raw: 00000007ffffffdc 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 5348, tgid 5348 (dhcpcd), ts 89814351085, free_ts 89837662630
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 folio_alloc_mpol_noprof mm/mempolicy.c:2435 [inline]
 vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2470
 folio_prealloc+0x30/0x180 mm/memory.c:-1
 wp_page_copy mm/memory.c:3679 [inline]
 do_wp_page+0x1231/0x5800 mm/memory.c:4140
 handle_pte_fault mm/memory.c:6193 [inline]
 __handle_mm_fault+0x1033/0x5400 mm/memory.c:6318
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487
 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
page last free pid 5348 tgid 5348 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:2963
 folios_put_refs+0x584/0x670 mm/swap.c:1002
 free_pages_and_swap_cache+0x4be/0x520 mm/swap_state.c:358
 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
 tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
 exit_mmap+0x444/0xb40 mm/mmap.c:1293
 __mmput+0x118/0x430 kernel/fork.c:1133
 exit_mm+0x1da/0x2c0 kernel/exit.c:582
 do_exit+0x648/0x2300 kernel/exit.c:954
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
 __do_sys_exit_group kernel/exit.c:1118 [inline]
 __se_sys_exit_group kernel/exit.c:1116 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1116
 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
 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

Memory state around the buggy address:
 ffff88804c384f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88804c384f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88804c385000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88804c385080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804c385100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================