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Date:   Mon, 22 May 2023 18:23:06 -0700
From:   Kees Cook <kees@kernel.org>
To:     Eric Biggers <ebiggers@kernel.org>,
        Kees Cook <keescook@chromium.org>
CC:     "Theodore Y. Ts'o" <tytso@mit.edu>,
        Jaegeuk Kim <jaegeuk@kernel.org>,
        "Gustavo A . R . Silva" <gustavoars@kernel.org>,
        linux-fscrypt@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org
Subject: Re: [PATCH] fscrypt: Replace 1-element array with flexible array
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On May 22, 2023 4:02:06 PM PDT, Eric Biggers <ebiggers@kernel=2Eorg> wrote:
>On Mon, May 22, 2023 at 02:39:28PM -0700, Kees Cook wrote:
>> In the future, we can add annotations for the flexible array member
>> "encrypted_path" to have a size determined by the "len" member=2E
>
>That seems unlikely, as 'struct fscrypt_symlink_data' is an on-disk data
>structure=2E  The "len" field does not necessarily use CPU endianness, an=
d before
>being validated it might be greater than the size of the allocated space=
=2E

Oh yes, good point=2E

>I agree that it should use a flex array (and thanks for catching this one=
 that I
>had forgotten about=2E=2E=2E), but the above explanation seems wrong=2E

Shall I spin a v2?


--=20
Kees Cook