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 writeback data mode.
==================================================================
BUG: KASAN: use-after-free in ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1447 [inline]
BUG: KASAN: use-after-free in ocfs2_claim_suballoc_bits+0x8b2/0x2450 fs/ocfs2/suballoc.c:1996
Read of size 4 at addr ffff888053bc6000 by task syz.0.0/5316

CPU: 0 UID: 0 PID: 5316 Comm: syz.0.0 Not tainted 6.15.0-rc7-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:408 [inline]
 print_report+0xb4/0x290 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1447 [inline]
 ocfs2_claim_suballoc_bits+0x8b2/0x2450 fs/ocfs2/suballoc.c:1996
 __ocfs2_claim_clusters+0x303/0x8f0 fs/ocfs2/suballoc.c:2421
 ocfs2_claim_clusters fs/ocfs2/suballoc.c:2458 [inline]
 ocfs2_block_group_alloc_contig fs/ocfs2/suballoc.c:432 [inline]
 ocfs2_block_group_alloc fs/ocfs2/suballoc.c:699 [inline]
 ocfs2_reserve_suballoc_bits+0xf1e/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+0x6a3/0x830 fs/open.c:338
 ksys_fallocate fs/open.c:362 [inline]
 __do_sys_fallocate fs/open.c:367 [inline]
 __se_sys_fallocate fs/open.c:365 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:365
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f92eef8e969
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:00007f92efecc038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f92ef1b5fa0 RCX: 00007f92eef8e969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f92ef010ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000001000f4 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f92ef1b5fa0 R15: 00007ffc17c51dd8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x7f63033ae pfn:0x53bc6
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea00014ef1c8 ffffea00014f01c8 0000000000000000
raw: 00000007f63033ae 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 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO|__GFP_COMP), pid 5298, tgid 5298 (udevd), ts 69053103524, free_ts 69096762874
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1714
 prep_new_page mm/page_alloc.c:1722 [inline]
 get_page_from_freelist+0x21ce/0x22b0 mm/page_alloc.c:3684
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4966
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
 folio_alloc_mpol_noprof mm/mempolicy.c:2320 [inline]
 vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2355
 folio_prealloc+0x30/0x180 mm/memory.c:-1
 alloc_anon_folio mm/memory.c:4943 [inline]
 do_anonymous_page mm/memory.c:5000 [inline]
 do_pte_missing mm/memory.c:4158 [inline]
 handle_pte_fault mm/memory.c:5997 [inline]
 __handle_mm_fault+0x2b28/0x5380 mm/memory.c:6140
 handle_mm_fault+0x3f6/0x8c0 mm/memory.c:6309
 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1388
 handle_page_fault arch/x86/mm/fault.c:1480 [inline]
 exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
page last free pid 5298 tgid 5298 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1258 [inline]
 free_unref_folios+0xb81/0x14a0 mm/page_alloc.c:2778
 folios_put_refs+0x559/0x640 mm/swap.c:992
 free_pages_and_swap_cache+0x4be/0x520 mm/swap_state.c:270
 __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:496
 vms_clear_ptes+0x42c/0x540 mm/vma.c:1191
 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1233
 do_vmi_align_munmap+0x358/0x420 mm/vma.c:1492
 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1540
 __vm_munmap+0x23b/0x3d0 mm/vma.c:3013
 __do_sys_munmap mm/mmap.c:1084 [inline]
 __se_sys_munmap mm/mmap.c:1081 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:1081
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888053bc5f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888053bc5f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888053bc6000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888053bc6080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888053bc6100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================