==================================================================
BUG: KASAN: use-after-free in ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1543
Read of size 1 at addr ffff888121c986e3 by task syz-executor.0/387

CPU: 0 PID: 387 Comm: syz-executor.0 Not tainted 6.1.99-syzkaller-1151470-g9e167c1c27c5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
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:1543
 ext4_find_inline_entry+0x4b6/0x5e0 fs/ext4/inline.c:1722
 __ext4_find_entry+0x2b0/0x1af0 fs/ext4/namei.c:1616
 ext4_lookup_entry fs/ext4/namei.c:1771 [inline]
 ext4_lookup+0x176/0x740 fs/ext4/namei.c:1839
 lookup_open fs/namei.c:3461 [inline]
 open_last_lookups fs/namei.c:3551 [inline]
 path_openat+0x10fd/0x2d60 fs/namei.c:3781
 do_filp_open+0x230/0x480 fs/namei.c:3811
 do_sys_openat2+0x151/0x870 fs/open.c:1341
 do_sys_open fs/open.c:1357 [inline]
 __do_sys_openat fs/open.c:1373 [inline]
 __se_sys_openat fs/open.c:1368 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1368
 x64_sys_call+0x6bf/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258
 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: 0033:0x7fed38e7de69
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:00007fed39c490c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fed38fabf80 RCX: 00007fed38e7de69
RDX: 000000000000275a RSI: 0000000020000280 RDI: ffffffffffffff9c
RBP: 00007fed38eca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fed38fabf80 R15: 00007ffcef2aa448
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0004872600 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x121c98
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea0004872648 ffffea00048725c8 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 294, tgid 294 (syz-execprog), ts 28108194154, free_ts 29180802652
 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+0x27ea/0x2870 mm/page_alloc.c:4425
 __alloc_pages+0x3a1/0x780 mm/page_alloc.c:5714
 __folio_alloc+0x15/0x40 mm/page_alloc.c:5746
 __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]
 wp_page_copy+0x261/0x1690 mm/memory.c:3190
 do_wp_page+0xc5c/0xf30
 handle_pte_fault mm/memory.c:5158 [inline]
 __handle_mm_fault mm/memory.c:5282 [inline]
 handle_mm_fault+0x15e0/0x30e0 mm/memory.c:5422
 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:3498
 free_unref_page_list+0xf1/0x7b0 mm/page_alloc.c:3646
 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+0xfe/0x1d0 mm/mmu_gather.c:261
 zap_pte_range mm/memory.c:1546 [inline]
 zap_pmd_range mm/memory.c:1595 [inline]
 zap_pud_range mm/memory.c:1624 [inline]
 zap_p4d_range mm/memory.c:1645 [inline]
 unmap_page_range+0x22d1/0x2620 mm/memory.c:1666
 unmap_single_vma mm/memory.c:1712 [inline]
 unmap_vmas+0x4e4/0x660 mm/memory.c:1752
 exit_mmap+0x2e7/0xbe0 mm/mmap.c:3335
 __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
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036
 x64_sys_call+0x610/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
 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

Memory state around the buggy address:
 ffff888121c98580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888121c98600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888121c98680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                       ^
 ffff888121c98700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888121c98780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop0): ext4_find_dest_de:2112: inode #12: block 5: comm syz-executor.0: bad entry in directory: rec_len % 4 != 0 - offset=0, inode=1375716473, rec_len=40042, size=56 fake=0