Re: [PATCH] ext4: fix OOB read when checking dotdot dir

From: Linus Torvalds
Date: Wed Mar 19 2025 - 12:29:28 EST


On Wed, 19 Mar 2025 at 06:06, Theodore Ts'o <tytso@xxxxxxx> wrote:
>
> I'd change the check to:
>
> else if (unlikely(next_offset == size && de->name_len == 1 &&
> strcmp(".", de->name) == 0))
>
> which is a bit more optimized.

Why would you use 'strcmp()' when you just checked that the length is one?

IOW, if you are talking about "a bit more optimized", please just check

de->name[0] == '.'

after you've checked that the length is 1.

No?

Linus