EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem
EXT4-fs (loop0): 1 truncate cleaned up
EXT4-fs (loop0): mounted filesystem without journal. Opts: jqfmt=vfsold,resgid=0x000000000000ee00,bh,noload,data_err=ignore,usrjquota=,,errors=continue
==================================================================
BUG: KASAN: use-after-free in ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1515
Read of size 1 at addr ffff888122b5cd23 by task syz-executor.0/354

CPU: 1 PID: 354 Comm: syz-executor.0 Not tainted 5.10.200-syzkaller-999710-g0da9a7bcb7a2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x81/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x179/0x1c0 mm/kasan/report.c:452
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1515
 ext4_find_inline_entry+0x4b6/0x5e0 fs/ext4/inline.c:1700
 __ext4_find_entry+0x2b0/0x1990 fs/ext4/namei.c:1588
 ext4_lookup_entry fs/ext4/namei.c:1743 [inline]
 ext4_lookup+0x3c6/0xaa0 fs/ext4/namei.c:1811
 __lookup_hash+0x143/0x290 fs/namei.c:1541
 filename_create+0x202/0x750 fs/namei.c:3614
 user_path_create fs/namei.c:3671 [inline]
 do_mkdirat+0xcc/0x2c0 fs/namei.c:3811
 __do_sys_mkdirat fs/namei.c:3829 [inline]
 __se_sys_mkdirat fs/namei.c:3827 [inline]
 __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3827
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xc6
RIP: 0033:0x7f8273e4dae9
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:00007f82739d00c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f8273f6cf80 RCX: 00007f8273e4dae9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: ffffffffffffff9c
RBP: 00007f8273e9947a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f8273f6cf80 R15: 00007ffcc7813e28

The buggy address belongs to the page:
page:ffffea00048ad700 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x122b5c
flags: 0x4000000000000000()
raw: 4000000000000000 ffffea00048ad748 ffffea00048ad6c8 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 354, ts 40563733498, free_ts 40565653266
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x166/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5346
 __alloc_pages include/linux/gfp.h:544 [inline]
 __alloc_pages_node include/linux/gfp.h:557 [inline]
 alloc_pages_node include/linux/gfp.h:571 [inline]
 alloc_pages include/linux/gfp.h:590 [inline]
 shmem_alloc_page+0x257/0x420 mm/shmem.c:1580
 shmem_alloc_and_acct_page+0x395/0x8e0 mm/shmem.c:1605
 shmem_getpage_gfp+0x891/0x2480 mm/shmem.c:1918
 shmem_getpage mm/shmem.c:161 [inline]
 shmem_write_begin+0xca/0x1b0 mm/shmem.c:2500
 generic_perform_write+0x2cd/0x570 mm/filemap.c:3509
 __generic_file_write_iter+0x23c/0x560 mm/filemap.c:3638
 generic_file_write_iter+0xaf/0x1c0 mm/filemap.c:3670
 call_write_iter include/linux/fs.h:1976 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0xb55/0xe70 fs/read_write.c:605
 ksys_write+0x199/0x2c0 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:667
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xc6
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2ae/0x2d0 mm/page_alloc.c:3336
 free_unref_page_list+0x122/0xb20 mm/page_alloc.c:3443
 release_pages+0xea0/0xef0 mm/swap.c:1103
 __pagevec_release+0x84/0x100 mm/swap.c:1123
 pagevec_release include/linux/pagevec.h:88 [inline]
 shmem_undo_range+0x7d1/0x1a60 mm/shmem.c:965
 shmem_truncate_range mm/shmem.c:1069 [inline]
 shmem_evict_inode+0x215/0x9d0 mm/shmem.c:1169
 evict+0x2a3/0x6c0 fs/inode.c:577
 iput_final fs/inode.c:1697 [inline]
 iput+0x632/0x7e0 fs/inode.c:1723
 dentry_unlink_inode+0x2e5/0x3d0 fs/dcache.c:374
 __dentry_kill+0x447/0x650 fs/dcache.c:579
 dentry_kill+0xc0/0x2a0
 dput+0x160/0x310 fs/dcache.c:878
 __fput+0x4f4/0x760 fs/file_table.c:294
 ____fput+0x15/0x20 fs/file_table.c:314
 task_work_run+0x129/0x190 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xbf/0xd0 kernel/entry/common.c:172

Memory state around the buggy address:
 ffff888122b5cc00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888122b5cc80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888122b5cd00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff888122b5cd80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888122b5ce00: 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:2076: 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