syzbot

loop0: detected capacity change from 0 to 32768
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BUG: KASAN: use-after-free in __ocfs2_find_path+0x203/0x7e0 fs/ocfs2/alloc.c:1824
Read of size 4 at addr ffff888072592000 by task syz-executor386/5831

CPU: 0 UID: 0 PID: 5831 Comm: syz-executor386 Not tainted 6.12.0-rc5-syzkaller-00005-ge42b1a9a2557 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 __ocfs2_find_path+0x203/0x7e0 fs/ocfs2/alloc.c:1824
 ocfs2_find_leaf+0xcf/0x230 fs/ocfs2/alloc.c:1938
 ocfs2_get_clusters_nocache+0x1ad/0xbf0 fs/ocfs2/extent_map.c:418
 ocfs2_get_clusters+0x5bd/0xbd0 fs/ocfs2/extent_map.c:621
 ocfs2_extent_map_get_blocks+0x24c/0x7d0 fs/ocfs2/extent_map.c:668
 ocfs2_read_virt_blocks+0x313/0xb20 fs/ocfs2/extent_map.c:983
 ocfs2_read_dir_block fs/ocfs2/dir.c:508 [inline]
 ocfs2_find_entry_el fs/ocfs2/dir.c:715 [inline]
 ocfs2_find_entry+0x43b/0x2780 fs/ocfs2/dir.c:1080
 ocfs2_find_files_on_disk+0xff/0x360 fs/ocfs2/dir.c:1981
 ocfs2_lookup_ino_from_name+0xb1/0x1e0 fs/ocfs2/dir.c:2003
 _ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline]
 ocfs2_get_system_file_inode+0x305/0x7b0 fs/ocfs2/sysfile.c:112
 ocfs2_init_global_system_inodes+0x32c/0x730 fs/ocfs2/super.c:457
 ocfs2_initialize_super fs/ocfs2/super.c:2248 [inline]
 ocfs2_fill_super+0x2f47/0x5750 fs/ocfs2/super.c:994
 mount_bdev+0x20a/0x2d0 fs/super.c:1679
 legacy_get_tree+0xee/0x190 fs/fs_context.c:662
 vfs_get_tree+0x90/0x2b0 fs/super.c:1800
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8bd9eb9dea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff38281748 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fff38281760 RCX: 00007f8bd9eb9dea
RDX: 0000000020004440 RSI: 0000000020000780 RDI: 00007fff38281760
RBP: 0000000000000004 R08: 00007fff382817a0 R09: 0000000000004444
R10: 0000000001000000 R11: 0000000000000282 R12: 0000000001000000
R13: 00007fff382817a0 R14: 0000000000000003 R15: 0000000001000000
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x7f8bd1a50 pfn:0x72592
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001c964c8 ffffea0001c844c8 0000000000000000
raw: 00000007f8bd1a50 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 5831, tgid 5831 (syz-executor386), ts 76292545624, free_ts 76475474079
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3039/0x3180 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 folio_alloc_mpol_noprof mm/mempolicy.c:2283 [inline]
 vma_alloc_folio_noprof+0x12e/0x230 mm/mempolicy.c:2314
 folio_prealloc+0x31/0x170
 alloc_anon_folio mm/memory.c:4716 [inline]
 do_anonymous_page mm/memory.c:4773 [inline]
 do_pte_missing mm/memory.c:3963 [inline]
 handle_pte_fault+0x24dd/0x6800 mm/memory.c:5755
 __handle_mm_fault mm/memory.c:5898 [inline]
 handle_mm_fault+0x1053/0x1ad0 mm/memory.c:6066
 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x459/0x8c0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
page last free pid 5831 tgid 5831 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_folios+0xee2/0x18a0 mm/page_alloc.c:2686
 folios_put_refs+0x76c/0x860 mm/swap.c:1007
 free_pages_and_swap_cache+0x5c8/0x690 mm/swap_state.c:335
 __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:366 [inline]
 tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373
 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465
 vms_clear_ptes+0x437/0x530 mm/vma.c:1096
 vms_complete_munmap_vmas+0x208/0x910 mm/vma.c:1140
 do_vmi_align_munmap+0x613/0x730 mm/vma.c:1349
 do_vmi_munmap+0x24e/0x2d0 mm/vma.c:1397
 __vm_munmap+0x24c/0x480 mm/mmap.c:1610
 __do_sys_munmap mm/mmap.c:1627 [inline]
 __se_sys_munmap mm/mmap.c:1624 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:1624
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888072591f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888072591f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888072592000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888072592080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888072592100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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