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Date:   Wed, 4 Oct 2023 21:53:13 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Justin Stitt <justinstitt@google.com>
Cc:     Shay Agroskin <shayagr@amazon.com>,
        Arthur Kiyanovski <akiyano@amazon.com>,
        David Arinzon <darinzon@amazon.com>,
        Noam Dagan <ndagan@amazon.com>,
        Saeed Bishara <saeedb@amazon.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH] net: ena: replace deprecated strncpy with strscpy
Message-ID: <202310042152.C8A84D30@keescook>
References: <20231005-strncpy-drivers-net-ethernet-amazon-ena-ena_netdev-c-v1-1-ba4879974160@google.com>
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In-Reply-To: <20231005-strncpy-drivers-net-ethernet-amazon-ena-ena_netdev-c-v1-1-ba4879974160@google.com>
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On Thu, Oct 05, 2023 at 12:56:08AM +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 necessary as host_info is initialized to
> `ena_dev->host_attr.host_info` which is ultimately zero-initialized via
> alloc_etherdev_mq().
> 
> 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>

Looks right to me. Length nicely adjusted. :)

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

-- 
Kees Cook