==================================================================
BUG: KASAN: use-after-free in ext4_search_dir+0xee/0x1b0 fs/ext4/namei.c:1504
Read of size 1 at addr ffff8881d10d03a2 by task syz-executor.3/537

CPU: 0 PID: 537 Comm: syz-executor.3 Tainted: G        W         5.4.268-syzkaller-00003-g2d5d8240a7cb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x241 lib/dump_stack.c:118
 print_address_description+0x8c/0x600 mm/kasan/report.c:384
 __kasan_report+0xf3/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 ext4_search_dir+0xee/0x1b0 fs/ext4/namei.c:1504
 ext4_find_inline_entry+0x4b6/0x5e0 fs/ext4/inline.c:1698
 __ext4_find_entry+0x2a9/0x1b50 fs/ext4/namei.c:1577
 ext4_lookup_entry fs/ext4/namei.c:1730 [inline]
 ext4_lookup+0x3c6/0xaa0 fs/ext4/namei.c:1798
 __lookup_hash+0x117/0x240 fs/namei.c:1623
 filename_create+0x202/0x750 fs/namei.c:3736
 user_path_create fs/namei.c:3793 [inline]
 do_mkdirat+0xc5/0x2c0 fs/namei.c:3931
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

The buggy address belongs to the page:
page:ffffea0007443400 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1
flags: 0x8000000000000000()
raw: 8000000000000000 ffffea0007443448 ffffea00074433c8 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)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x18f/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4891
 __alloc_pages include/linux/gfp.h:503 [inline]
 __alloc_pages_node include/linux/gfp.h:516 [inline]
 alloc_pages_node include/linux/gfp.h:530 [inline]
 shmem_alloc_page mm/shmem.c:1503 [inline]
 shmem_alloc_and_acct_page+0x492/0x9d0 mm/shmem.c:1528
 shmem_getpage_gfp+0xf5d/0x2440 mm/shmem.c:1852
 shmem_getpage mm/shmem.c:154 [inline]
 shmem_write_begin+0xc9/0x1a0 mm/shmem.c:2447
 generic_perform_write+0x2c7/0x560 mm/filemap.c:3450
 __generic_file_write_iter+0x224/0x530 mm/filemap.c:3579
 generic_file_write_iter+0x455/0x5f0 mm/filemap.c:3611
 call_write_iter include/linux/fs.h:1983 [inline]
 new_sync_write fs/read_write.c:483 [inline]
 __vfs_write+0x5d3/0x750 fs/read_write.c:496
 vfs_write+0x206/0x4e0 fs/read_write.c:558
 ksys_write+0x199/0x2c0 fs/read_write.c:611
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1176 [inline]
 free_pcp_prepare mm/page_alloc.c:1233 [inline]
 free_unref_page_prepare+0x297/0x380 mm/page_alloc.c:3085
 free_unref_page_list+0x10a/0x590 mm/page_alloc.c:3154
 release_pages+0xad8/0xb20 mm/swap.c:842
 __pagevec_release+0xc3/0x150 mm/swap.c:862
 pagevec_release include/linux/pagevec.h:88 [inline]
 shmem_undo_range+0x8a5/0x1ad0 mm/shmem.c:875
 shmem_truncate_range mm/shmem.c:997 [inline]
 shmem_evict_inode+0x218/0x9a0 mm/shmem.c:1097
 evict+0x29b/0x6a0 fs/inode.c:575
 __dentry_kill+0x429/0x630 fs/dcache.c:579
 dentry_kill+0xb8/0x280 fs/dcache.c:673
 dput+0x154/0x2f0 fs/dcache.c:859
 __fput+0x443/0x680 fs/file_table.c:294
 task_work_run+0x140/0x170 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x190/0x1a0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Memory state around the buggy address:
 ffff8881d10d0280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881d10d0300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881d10d0380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff8881d10d0400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881d10d0480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop3): ext4_check_all_de:657: inode #12: block 5: comm syz-executor.3: bad entry in directory: directory entry overrun - offset=0, inode=4190095285, rec_len=57668, size=124 fake=0
EXT4-fs error (device loop3): ext4_find_dest_de:2063: inode #12: block 5: comm syz-executor.3: bad entry in directory: directory entry overrun - offset=0, inode=4190095285, rec_len=57668, size=56 fake=0