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BUG: KASAN: use-after-free in ocfs2_dx_dir_lookup_rec+0x1eb/0x7f0 fs/ocfs2/dir.c:813
Read of size 4 at addr ffff8880534492c0 by task syz.0.0/5317

CPU: 0 UID: 0 PID: 5317 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_dx_dir_lookup_rec+0x1eb/0x7f0 fs/ocfs2/dir.c:813
 ocfs2_dx_dir_lookup+0xdb/0x520 fs/ocfs2/dir.c:868
 ocfs2_dx_dir_search fs/ocfs2/dir.c:928 [inline]
 ocfs2_find_entry_dx fs/ocfs2/dir.c:1042 [inline]
 ocfs2_find_entry+0x1004/0x2000 fs/ocfs2/dir.c:1079
 ocfs2_find_files_on_disk+0xef/0x340 fs/ocfs2/dir.c:2002
 ocfs2_lookup_ino_from_name+0x52/0x100 fs/ocfs2/dir.c:2024
 ocfs2_lookup+0x255/0x9b0 fs/ocfs2/namei.c:122
 __lookup_slow+0x297/0x3d0 fs/namei.c:1816
 lookup_slow+0x53/0x70 fs/namei.c:1833
 walk_component+0x2d2/0x400 fs/namei.c:2151
 lookup_last fs/namei.c:2652 [inline]
 path_lookupat+0x163/0x430 fs/namei.c:2676
 filename_lookup+0x212/0x570 fs/namei.c:2705
 kern_path+0x35/0x50 fs/namei.c:2863
 unix_find_bsd net/unix/af_unix.c:1236 [inline]
 unix_find_other+0x183/0xb40 net/unix/af_unix.c:1298
 unix_dgram_sendmsg+0x76e/0x18d0 net/unix/af_unix.c:2174
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x52d/0x830 net/socket.c:2630
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
 __sys_sendmmsg+0x227/0x430 net/socket.c:2773
 __do_sys_sendmmsg net/socket.c:2800 [inline]
 __se_sys_sendmmsg net/socket.c:2797 [inline]
 __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2797
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4e33d8efc9
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:00007f4e301cc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f4e33fe6090 RCX: 00007f4e33d8efc9
RDX: 0000000000000002 RSI: 0000200000005a40 RDI: 0000000000000004
RBP: 00007f4e33e11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4e33fe6128 R14: 00007f4e33fe6090 R15: 00007ffcb0b98a38
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x7fad37e31 pfn:0x53449
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea00014d0f08 ffffea00014d2248 0000000000000000
raw: 00000007fad37e31 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 5293, tgid 5293 (udevd), ts 68589805338, free_ts 68624110974
 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
 alloc_anon_folio mm/memory.c:5125 [inline]
 do_anonymous_page mm/memory.c:5182 [inline]
 do_pte_missing mm/memory.c:4359 [inline]
 handle_pte_fault mm/memory.c:6177 [inline]
 __handle_mm_fault+0x2a8b/0x5400 mm/memory.c:6318
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487
 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
page last free pid 5293 tgid 5293 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
 vms_clear_ptes+0x42c/0x540 mm/vma.c:1235
 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1277
 do_vmi_align_munmap+0x364/0x440 mm/vma.c:1536
 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584
 __vm_munmap+0x207/0x380 mm/vma.c:3156
 __do_sys_munmap mm/mmap.c:1080 [inline]
 __se_sys_munmap mm/mmap.c:1077 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:1077
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888053449180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888053449200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888053449280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff888053449300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888053449380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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