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From: Kees Cook <keescook@chromium.org>
To: Justin Stitt <justinstitt@google.com>
Cc: Andrew Lunn <andrew@lunn.ch>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Vladimir Oltean <olteanv@gmail.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 v2] net: dsa: vsc73xx: replace deprecated strncpy with ethtool_sprintf
Date: Tue, 10 Oct 2023 16:58:14 -0700	[thread overview]
Message-ID: <202310101658.84E1C724@keescook> (raw)
In-Reply-To: <20231010-strncpy-drivers-net-dsa-vitesse-vsc73xx-core-c-v2-1-ba4416a9ff23@google.com>

On Tue, Oct 10, 2023 at 10:32:35PM +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.
> 
> ethtool_sprintf() is designed specifically for get_strings() usage.
> Let's replace strncpy in favor of this more robust and easier to
> understand interface.
> 
> This change could result in misaligned strings when if(cnt) fails. To
> combat this, use ternary to place empty string in buffer and properly
> increment pointer to next string slot.
> 
> 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>

Nice; much more readable.

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

-- 
Kees Cook

  reply	other threads:[~2023-10-10 23:58 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-10 22:32 [PATCH v2] net: dsa: vsc73xx: replace deprecated strncpy with ethtool_sprintf Justin Stitt
2023-10-10 23:58 ` Kees Cook [this message]
2023-10-14  0:00 ` patchwork-bot+netdevbpf

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