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BUG: KASAN: use-after-free in ext4_search_dir+0x1b7/0x1d0 fs/ext4/namei.c:1543
Read of size 1 at addr ffff8880974ef1ec by task syz-executor.1/16133

CPU: 1 PID: 16133 Comm: syz-executor.1 Not tainted 6.6.0-rc5-syzkaller-00055-g1c8b86a3799f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xc4/0x620 mm/kasan/report.c:475
 kasan_report+0xda/0x110 mm/kasan/report.c:588
 ext4_search_dir+0x1b7/0x1d0 fs/ext4/namei.c:1543
 ext4_find_inline_entry+0x432/0x4f0 fs/ext4/inline.c:1694
 __ext4_find_entry+0x85e/0x1050 fs/ext4/namei.c:1616
 ext4_lookup_entry fs/ext4/namei.c:1771 [inline]
 ext4_lookup+0x543/0x740 fs/ext4/namei.c:1839
 lookup_one_qstr_excl+0x116/0x180 fs/namei.c:1608
 filename_create+0x1ed/0x530 fs/namei.c:3890
 do_mkdirat+0xb3/0x330 fs/namei.c:4135
 __do_sys_mkdir fs/namei.c:4163 [inline]
 __se_sys_mkdir fs/namei.c:4161 [inline]
 __x64_sys_mkdir+0xf2/0x140 fs/namei.c:4161
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f539a47cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f539b2960c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f539a59bf80 RCX: 00007f539a47cae9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000280
RBP: 00007f539a4c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f539a59bf80 R15: 00007fff50e2db38
 </TASK>

The buggy address belongs to the physical page:
page:ffffea00025d3bc0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x974ef
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 ffffea00025d3c08 ffffea00025d3b88 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 16136, tgid 16135 (syz-executor.3), ts 634989115484, free_ts 635026877236
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536
 prep_new_page mm/page_alloc.c:1543 [inline]
 get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170
 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426
 __folio_alloc+0x16/0x40 mm/page_alloc.c:4458
 vma_alloc_folio+0x156/0x890 mm/mempolicy.c:2258
 wp_page_copy mm/memory.c:3070 [inline]
 do_wp_page+0x1971/0x3420 mm/memory.c:3449
 handle_pte_fault mm/memory.c:4994 [inline]
 __handle_mm_fault+0x1d1b/0x3e10 mm/memory.c:5119
 handle_mm_fault+0x478/0xa00 mm/memory.c:5284
 do_user_addr_fault+0x30b/0x1000 arch/x86/mm/fault.c:1364
 handle_page_fault arch/x86/mm/fault.c:1505 [inline]
 exc_page_fault+0x5c/0xd0 arch/x86/mm/fault.c:1561
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1136 [inline]
 free_unref_page_prepare+0x476/0xa40 mm/page_alloc.c:2312
 free_unref_page_list+0xe6/0xb30 mm/page_alloc.c:2451
 release_pages+0x32a/0x14e0 mm/swap.c:1042
 tlb_batch_pages_flush+0x9a/0x190 mm/mmu_gather.c:98
 tlb_flush_mmu_free mm/mmu_gather.c:293 [inline]
 tlb_flush_mmu mm/mmu_gather.c:300 [inline]
 tlb_finish_mmu+0x14b/0x6f0 mm/mmu_gather.c:392
 unmap_region.constprop.0+0x2e6/0x3b0 mm/mmap.c:2318
 do_vmi_align_munmap+0xddc/0x15f0 mm/mmap.c:2555
 do_vmi_munmap+0x20e/0x450 mm/mmap.c:2623
 __vm_munmap+0x144/0x390 mm/mmap.c:2908
 __do_sys_munmap mm/mmap.c:2925 [inline]
 __se_sys_munmap mm/mmap.c:2922 [inline]
 __x64_sys_munmap+0x62/0x80 mm/mmap.c:2922
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff8880974ef080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880974ef100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880974ef180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                          ^
 ffff8880974ef200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880974ef280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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