Re: [PATCH v2] ext4: validate readdir offset before accessing dirent

[Theodore Ts'o]

On Mon, 06 Jul 2026 12:13:13 +0800, Yao Kai wrote:
> A corrupted directory can trigger the following KASAN report when
> ext4_readdir() resumes from an invalid position:
> 
>   BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x5ef/0x820
>   Read of size 2 at addr ffff88810a646000 by task repro_linear/509
> 
>   Call Trace:
>    <TASK>
>    dump_stack_lvl+0x53/0x70
>    print_report+0xd0/0x630
>    kasan_report+0xce/0x100
>    __ext4_check_dir_entry+0x5ef/0x820
>    ext4_readdir+0xcde/0x2b70
>    iterate_dir+0x1a1/0x520
>    __x64_sys_getdents64+0x12b/0x220
>    do_syscall_64+0xf9/0x540
>    entry_SYSCALL_64_after_hwframe+0x77/0x7f
>    </TASK>
> 
> [...]

Applied, thanks!

[1/1] ext4: validate readdir offset before accessing dirent
      commit: bc4b7b0414c33b2c8898eb04386df0d21a13dad8

Best regards,
-- 
Theodore Ts'o <tytso@xxxxxxx>