EXT4-fs warning (device loop2): dx_probe:833: inode #2: comm syz.2.17: Unrecognised inode hash code 4
EXT4-fs warning (device loop2): dx_probe:966: inode #2: comm syz.2.17: Corrupt directory, running e2fsck is recommended
==================================================================
BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x7c2/0x970 fs/ext4/dir.c:85
Read of size 2 at addr ffff888130200003 by task syz.2.17/362

CPU: 1 PID: 362 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_address_description+0x71/0x200 mm/kasan/report.c:316
 print_report+0x4a/0x60 mm/kasan/report.c:420
 kasan_report+0x122/0x150 mm/kasan/report.c:524
 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report_generic.c:349
 __ext4_check_dir_entry+0x7c2/0x970 fs/ext4/dir.c:85
 ext4_readdir+0x1315/0x3e10 fs/ext4/dir.c:261
 iterate_dir+0x271/0x610 fs/readdir.c:-1
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0xf2/0x250 fs/readdir.c:354
 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354
 x64_sys_call+0x15c/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:218
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa88359c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff7d686be8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007fa883815fa0 RCX: 00007fa88359c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007fa883632c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa883815fac R14: 00007fa883815fa0 R15: 00007fa883815fa0
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0004c08000 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x130200
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffffff878e7438 ffffffff878e7438 0000000000000000
raw: 0000000000000000 0000000000000009 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffff8881301fff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881301fff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888130200000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888130200080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888130200100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop2): ext4_readdir:263: inode #2: block 255: comm syz.2.17: path /0/file0: bad entry in directory: rec_len is smaller than minimal - offset=1023, inode=0, rec_len=0, size=1024 fake=0