EXT4-fs (loop1): mounted filesystem without journal. Quota mode: none.
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BUG: KASAN: use-after-free in ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1544
Read of size 1 at addr ffff88812dcc1d0b by task syz.1.16/499

CPU: 0 PID: 499 Comm: syz.1.16 Not tainted 6.1.112-syzkaller-1151942-g19b68814b1cd #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0x158/0x4e0 mm/kasan/report.c:427
 kasan_report+0x13c/0x170 mm/kasan/report.c:531
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:348
 ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1544
 ext4_find_inline_entry+0x4b6/0x5e0 fs/ext4/inline.c:1726
 __ext4_find_entry+0x2b0/0x1af0 fs/ext4/namei.c:1617
 ext4_lookup_entry fs/ext4/namei.c:1772 [inline]
 ext4_lookup+0x176/0x740 fs/ext4/namei.c:1840
 __lookup_slow+0x2b9/0x3e0 fs/namei.c:1689
 lookup_slow+0x5a/0x80 fs/namei.c:1706
 walk_component+0x2e7/0x410 fs/namei.c:1997
 lookup_last fs/namei.c:2454 [inline]
 path_lookupat+0x16d/0x450 fs/namei.c:2478
 filename_lookup+0x251/0x600 fs/namei.c:2507
 user_path_at_empty+0x43/0x1a0 fs/namei.c:2906
 user_path_at include/linux/namei.h:57 [inline]
 do_mount fs/namespace.c:3391 [inline]
 __do_sys_mount fs/namespace.c:3602 [inline]
 __se_sys_mount+0x285/0x3b0 fs/namespace.c:3579
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3579
 x64_sys_call+0x49d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbc25b77299
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:00007fbc269c2048 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fbc25d05f80 RCX: 00007fbc25b77299
RDX: 0000000000000000 RSI: 0000000020002ac0 RDI: 0000000000000000
RBP: 00007fbc25be48e6 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fbc25d05f80 R15: 00007fff531b5ec8
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0004b73040 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x12dcc1
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea0004b73088 ffffea0004b73008 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 458, tgid 458 (syz-executor), ts 52285470855, free_ts 52704361713
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x213/0x220 mm/page_alloc.c:2590
 prep_new_page+0x1b/0x110 mm/page_alloc.c:2597
 get_page_from_freelist+0x2980/0x2a10 mm/page_alloc.c:4439
 __alloc_pages+0x234/0x610 mm/page_alloc.c:5728
 __folio_alloc+0x15/0x40 mm/page_alloc.c:5760
 __folio_alloc_node include/linux/gfp.h:245 [inline]
 folio_alloc include/linux/gfp.h:274 [inline]
 alloc_page_vma include/linux/gfp.h:283 [inline]
 do_cow_fault mm/memory.c:4746 [inline]
 do_fault+0x4e8/0x1f10 mm/memory.c:4862
 handle_pte_fault mm/memory.c:5156 [inline]
 __handle_mm_fault mm/memory.c:5298 [inline]
 handle_mm_fault+0x189f/0x30e0 mm/memory.c:5438
 do_user_addr_fault arch/x86/mm/fault.c:1323 [inline]
 handle_page_fault arch/x86/mm/fault.c:1466 [inline]
 exc_page_fault+0x3b3/0x6d0 arch/x86/mm/fault.c:1522
 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:570
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1498 [inline]
 free_pcp_prepare mm/page_alloc.c:1572 [inline]
 free_unref_page_prepare+0x83d/0x850 mm/page_alloc.c:3511
 free_unref_page_list+0xf1/0x7b0 mm/page_alloc.c:3659
 release_pages+0xf7f/0xfe0 mm/swap.c:1063
 free_pages_and_swap_cache+0x8a/0xa0 mm/swap_state.c:315
 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
 tlb_flush_mmu mm/mmu_gather.c:261 [inline]
 tlb_finish_mmu+0x1e0/0x3f0 mm/mmu_gather.c:361
 exit_mmap+0x460/0xbe0 mm/mmap.c:3348
 __mmput+0x95/0x310 kernel/fork.c:1298
 mmput+0x56/0x170 kernel/fork.c:1321
 exit_mm kernel/exit.c:568 [inline]
 do_exit+0xb29/0x2b80 kernel/exit.c:864
 do_group_exit+0x21a/0x2d0 kernel/exit.c:1027
 get_signal+0x169d/0x1820 kernel/signal.c:2888
 arch_do_signal_or_restart+0xb0/0x16f0 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x74/0xa0 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x26/0x130 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87

Memory state around the buggy address:
 ffff88812dcc1c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812dcc1c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88812dcc1d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff88812dcc1d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812dcc1e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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