[Android 6.1] KASAN: use-after-free Read in ext4_search_dir

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 53771c1826da ANDROID: Update the ABI symbol list
git tree: android14-6.1
console+strace: https://syzkaller.appspot.com/x/log.txt?x=128e2905680000
kernel config: https://syzkaller.appspot.com/x/.config?x=3bacf1dde2aec241
dashboard link: https://syzkaller.appspot.com/bug?extid=0d932da7cfedad13bd42
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1294e125680000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=115fd671680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f1d680ce5f50/disk-53771c18.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4e844c4141e8/vmlinux-53771c18.xz
kernel image: https://storage.googleapis.com/syzbot-assets/228ff69bbe13/bzImage-53771c18.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/40ca6051601a/mount_0.gz
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/b123880dc391/mount_7.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0d932d...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1523
Read of size 1 at addr ffff888122055d23 by task syz-executor543/295

CPU: 1 PID: 295 Comm: syz-executor543 Not tainted 6.1.25-syzkaller-00041-g53771c1826da #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
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:1523
ext4_find_inline_entry+0x4b6/0x5e0 fs/ext4/inline.c:1711
__ext4_find_entry+0x2b0/0x1af0 fs/ext4/namei.c:1596
ext4_lookup_entry fs/ext4/namei.c:1751 [inline]
ext4_lookup+0x176/0x740 fs/ext4/namei.c:1819
lookup_open fs/namei.c:3391 [inline]
open_last_lookups fs/namei.c:3481 [inline]
path_openat+0x10fd/0x2d60 fs/namei.c:3711
do_filp_open+0x230/0x480 fs/namei.c:3741
do_sys_openat2+0x13f/0x850 fs/open.c:1333
do_sys_open fs/open.c:1349 [inline]
__do_sys_creat fs/open.c:1425 [inline]
__se_sys_creat fs/open.c:1419 [inline]
__x64_sys_creat+0x11f/0x160 fs/open.c:1419
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+0x63/0xcd
RIP: 0033:0x7f49331a4529
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcdbdcfa98 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f49331ed08d RCX: 00007f49331a4529
RDX: 00007f49331a36c0 RSI: 0000000000000000 RDI: 0000000020000e00
RBP: 0030656c69662f2e R08: 00000000000014ef R09: 0000000020001580
R10: 00000000000014f3 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 431bde82d7b634db R15: 00007ffcdbdcfb00
</TASK>

The buggy address belongs to the physical page:
page:ffffea0004881540 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x122055
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea0004881588 ffffea0004881508 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
ffff888122055c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888122055c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888122055d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff888122055d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888122055e00: 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:2092: inode #12: block 7: comm syz-executor543: bad entry in directory: rec_len % 4 != 0 - offset=0, inode=3089191003, rec_len=43069, size=56 fake=0


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