==================================================================
BUG: KASAN: use-after-free in ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1543
Read of size 1 at addr ffff888122948d23 by task syz-executor.0/348

CPU: 1 PID: 348 Comm: syz-executor.0 Not tainted 5.15.149-syzkaller-1069274-g85445b5a2107 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
 print_address_description+0x87/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:427 [inline]
 kasan_report+0x179/0x1c0 mm/kasan/report.c:444
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1543
 ext4_find_inline_entry+0x4b6/0x5e0 fs/ext4/inline.c:1714
 __ext4_find_entry+0x2b0/0x1af0 fs/ext4/namei.c:1616
 ext4_lookup_entry fs/ext4/namei.c:1771 [inline]
 ext4_lookup+0x3c6/0xaa0 fs/ext4/namei.c:1839
 lookup_one_qstr_excl+0x143/0x290 fs/namei.c:1563
 filename_create+0x28e/0x530 fs/namei.c:3836
 do_mkdirat+0xbd/0x450 fs/namei.c:4080
 __do_sys_mkdirat fs/namei.c:4105 [inline]
 __se_sys_mkdirat fs/namei.c:4103 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4103
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f7f84a53ae9
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:00007f7f845d60c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f7f84b72f80 RCX: 00007f7f84a53ae9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: ffffffffffffff9c
RBP: 00007f7f84a9f47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f7f84b72f80 R15: 00007ffd9496eb68
 </TASK>

The buggy address belongs to the page:
page:ffffea00048a5200 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x122948
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea00048a5248 ffffea00048a51c8 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 0x100cca(GFP_HIGHUSER_MOVABLE), pid 348, ts 35224602390, free_ts 35247349760
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1a3/0x1b0 mm/page_alloc.c:2604
 prep_new_page+0x1b/0x110 mm/page_alloc.c:2610
 get_page_from_freelist+0x3550/0x35d0 mm/page_alloc.c:4484
 __alloc_pages+0x27e/0x8f0 mm/page_alloc.c:5776
 __alloc_pages_node include/linux/gfp.h:591 [inline]
 alloc_pages_node include/linux/gfp.h:605 [inline]
 alloc_pages include/linux/gfp.h:618 [inline]
 shmem_alloc_page mm/shmem.c:1587 [inline]
 shmem_alloc_and_acct_page+0x4bd/0xa80 mm/shmem.c:1612
 shmem_getpage_gfp+0x1388/0x23c0 mm/shmem.c:1907
 shmem_getpage mm/shmem.c:152 [inline]
 shmem_write_begin+0xca/0x1b0 mm/shmem.c:2478
 generic_perform_write+0x2bc/0x5a0 mm/filemap.c:3849
 __generic_file_write_iter+0x25b/0x4b0 mm/filemap.c:3976
 generic_file_write_iter+0xaf/0x1c0 mm/filemap.c:4008
 call_write_iter include/linux/fs.h:2202 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0xd5d/0x1110 fs/read_write.c:594
 ksys_write+0x199/0x2c0 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:656
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1471 [inline]
 free_pcp_prepare mm/page_alloc.c:1543 [inline]
 free_unref_page_prepare+0x7c8/0x7d0 mm/page_alloc.c:3533
 free_unref_page_list+0x14b/0xa60 mm/page_alloc.c:3670
 release_pages+0x1310/0x1370 mm/swap.c:1009
 __pagevec_release+0x84/0x100 mm/swap.c:1029
 pagevec_release include/linux/pagevec.h:81 [inline]
 shmem_undo_range+0x604/0x1560 mm/shmem.c:965
 shmem_truncate_range mm/shmem.c:1064 [inline]
 shmem_evict_inode+0x215/0x9d0 mm/shmem.c:1146
 evict+0x2a3/0x630 fs/inode.c:587
 iput_final fs/inode.c:1705 [inline]
 iput+0x63b/0x7e0 fs/inode.c:1731
 dentry_unlink_inode+0x34f/0x440 fs/dcache.c:376
 __dentry_kill+0x447/0x660 fs/dcache.c:582
 dentry_kill+0xc0/0x2a0
 dput+0x45/0x80 fs/dcache.c:889
 __fput+0x662/0x910 fs/file_table.c:288
 ____fput+0x15/0x20 fs/file_table.c:308
 task_work_run+0x129/0x190 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0xc4/0xe0 kernel/entry/common.c:175

Memory state around the buggy address:
 ffff888122948c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888122948c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888122948d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff888122948d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888122948e00: 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 7: comm syz-executor.0: bad entry in directory: rec_len % 4 != 0 - offset=0, inode=3089191003, rec_len=43069, size=56 fake=0