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Date:   Wed, 4 Oct 2023 19:58:39 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Justin Stitt <justinstitt@google.com>
Cc:     Wolfgang Grandegger <wg@grandegger.com>,
        Marc Kleine-Budde <mkl@pengutronix.de>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, linux-can@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org
Subject: Re: [PATCH] can: peak_pci: replace deprecated strncpy with strscpy
Message-ID: <202310041958.12F8A261A@keescook>
References: <20231005-strncpy-drivers-net-can-sja1000-peak_pci-c-v1-1-c36e1702cd56@google.com>
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In-Reply-To: <20231005-strncpy-drivers-net-can-sja1000-peak_pci-c-v1-1-c36e1702cd56@google.com>
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On Thu, Oct 05, 2023 at 12:05:35AM +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings
> [1] and as such we should prefer more robust and less ambiguous string
> interfaces.
> 
> NUL-padding is not required since card is already zero-initialized:
> |       card = kzalloc(sizeof(*card), GFP_KERNEL);
> 
> A suitable replacement is `strscpy` [2] due to the fact that it
> guarantees NUL-termination on the destination buffer without
> unnecessarily NUL-padding.
> 
> 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>

Yup, this looks like a standard direct replacement.

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

-- 
Kees Cook