BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x700/0x880 fs/ext4/dir.c:85
Read of size 2 at addr ffff888123b35003 by task syz-executor.0/345

CPU: 0 PID: 345 Comm: syz-executor.0 Not tainted 5.10.214-syzkaller-1001996-ga8e7f812fbc1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
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_load2_noabort+0x14/0x20 mm/kasan/report_generic.c:307
 __ext4_check_dir_entry+0x700/0x880 fs/ext4/dir.c:85
 ext4_readdir+0x1402/0x37c0 fs/ext4/dir.c:258
 iterate_dir+0x265/0x580
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0x1c1/0x460 fs/readdir.c:354
 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xc6
RIP: 0033:0x7f7609001d69
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:00007f7608b830c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007f760912ff80 RCX: 00007f7609001d69
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f760904e49e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f760912ff80 R15: 00007ffd1c544b98

The buggy address belongs to the page:
page:ffffea00048ecd40 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x123b35
flags: 0x4000000000000000()
raw: 4000000000000000 ffffea00048ecd88 ffff8881f725ab70 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffff888123b34f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888123b34f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888123b35000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888123b35080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888123b35100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop0): ext4_readdir:260: inode #2: block 255: comm syz-executor.0: path /root/syzkaller-testdir1434163684/syzkaller.QUt0DP/0/file0: bad entry in directory: rec_len is smaller than minimal - offset=1023, inode=3160121600, rec_len=0, size=1024 fake=0