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Date:   Thu, 14 Sep 2023 21:03:29 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Justin Stitt <justinstitt@google.com>
Cc:     Nishanth Menon <nm@ti.com>, Tero Kristo <kristo@kernel.org>,
        Santosh Shilimkar <ssantosh@kernel.org>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org
Subject: Re: [PATCH] firmware: ti_sci: refactor deprecated strncpy
Message-ID: <202309142103.6DFFDEB@keescook>
References: <20230913-strncpy-drivers-firmware-ti_sci-c-v1-1-740db471110d@google.com>
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On Wed, Sep 13, 2023 at 08:23:02PM +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings [1].
> 
> We should prefer more robust and less ambiguous string interfaces.
> 
> A suitable replacement is `strscpy` [2] due to the fact that it guarantees
> NUL-termination on the destination buffer.
> 
> It does not seem like `ver->firmware_description` requires NUL-padding
> (which is a behavior that strncpy provides) but if it does let's opt for
> `strscpy_pad()`.
> 
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Signed-off-by: Justin Stitt <justinstitt@google.com>

Looks right to me.

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook