syzbot

loop0: detected capacity change from 0 to 32768
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
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BUG: KASAN: use-after-free in ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1391 [inline]
BUG: KASAN: use-after-free in ocfs2_claim_suballoc_bits+0xeb0/0x2230 fs/ocfs2/suballoc.c:1927
Read of size 4 at addr ffff888060a32000 by task syz.0.34/5999

CPU: 0 PID: 5999 Comm: syz.0.34 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xac/0x220 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1391 [inline]
 ocfs2_claim_suballoc_bits+0xeb0/0x2230 fs/ocfs2/suballoc.c:1927
 ocfs2_claim_new_inode+0x32a/0x780 fs/ocfs2/suballoc.c:2210
 ocfs2_mknod_locked+0x101/0x250 fs/ocfs2/namei.c:635
 ocfs2_mknod+0x107e/0x20f0 fs/ocfs2/namei.c:381
 ocfs2_create+0x196/0x410 fs/ocfs2/namei.c:674
 lookup_open fs/namei.c:3488 [inline]
 open_last_lookups fs/namei.c:3556 [inline]
 path_openat+0x1277/0x3190 fs/namei.c:3786
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
 do_sys_open fs/open.c:1434 [inline]
 __do_sys_creat fs/open.c:1512 [inline]
 __se_sys_creat fs/open.c:1506 [inline]
 __x64_sys_creat+0x90/0xb0 fs/open.c:1506
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f59c498eb69
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:00007fff7445f5f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f59c4bb5fa0 RCX: 00007f59c498eb69
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000d80
RBP: 00007f59c4a11df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f59c4bb5fa0 R14: 00007f59c4bb5fa0 R15: 0000000000000002
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0001828c80 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x60a32
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 ffffea0001828588 ffff8880b8e42360 0000000000000000
raw: 0000000000000001 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_COMP|__GFP_ZERO), pid 5999, tgid 5999 (syz.0.34), ts 116236477085, free_ts 116494959321
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 __folio_alloc+0x10/0x20 mm/page_alloc.c:4489
 vma_alloc_folio+0x47a/0x8f0 mm/mempolicy.c:2242
 do_anonymous_page mm/memory.c:4149 [inline]
 do_pte_missing mm/memory.c:3686 [inline]
 handle_pte_fault mm/memory.c:5025 [inline]
 __handle_mm_fault mm/memory.c:5166 [inline]
 handle_mm_fault+0x1a38/0x4920 mm/memory.c:5331
 do_user_addr_fault+0xad0/0x12e0 arch/x86/mm/fault.c:1324
 handle_page_fault arch/x86/mm/fault.c:1465 [inline]
 exc_page_fault+0x67/0x110 arch/x86/mm/fault.c:1521
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1154 [inline]
 free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
 free_unref_page_list+0xbe/0x860 mm/page_alloc.c:2475
 release_pages+0x1fa0/0x2220 mm/swap.c:1022
 tlb_batch_pages_flush mm/mmu_gather.c:98 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:293 [inline]
 tlb_flush_mmu+0x368/0x4f0 mm/mmu_gather.c:300
 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:392
 unmap_region+0x2ed/0x340 mm/mmap.c:2345
 do_vmi_align_munmap+0xffe/0x1660 mm/mmap.c:2588
 do_vmi_munmap+0x252/0x2d0 mm/mmap.c:2656
 __vm_munmap+0x193/0x3c0 mm/mmap.c:2957
 __do_sys_munmap mm/mmap.c:2974 [inline]
 __se_sys_munmap mm/mmap.c:2971 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:2971
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff888060a31f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888060a31f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888060a32000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888060a32080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888060a32100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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