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,
Alexander Lobakin <aleksander.lobakin@intel.com>
Subject: Re: [PATCH v2] net: dsa: lan9303: use ethtool_sprintf() for lan9303_get_strings()
Date: Thu, 5 Oct 2023 15:42:08 -0700 [thread overview]
Message-ID: <202310051539.B2D34DB@keescook> (raw)
In-Reply-To: <20231005-strncpy-drivers-net-dsa-lan9303-core-c-v2-1-feb452a532db@google.com>
On Thu, Oct 05, 2023 at 06:56:50PM +0000, Justin Stitt wrote:
> This pattern of strncpy with some pointer arithmetic setting fixed-sized
> intervals with string literal data is a bit weird so let's use
> ethtool_sprintf() as this has more obvious behavior and is less-error
> prone.
>
> Nicely, we also get to drop a usage of the now deprecated strncpy() [1].
>
> One might consider this pattern:
> | ethtool_sprintf(&buf, lan9303_mib[u].name);
> ... but this triggers a -Wformat-security warning.
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Cc: Kees Cook <keescook@chromium.org>
> Signed-off-by: Justin Stitt <justinstitt@google.com>
Ah, cool ethtool_sprintf() works. Maybe some day we can fix the whole
API to actually have bounds, but yes, this is fine.
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
next prev parent reply other threads:[~2023-10-05 22:42 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-05 18:56 [PATCH v2] net: dsa: lan9303: use ethtool_sprintf() for lan9303_get_strings() Justin Stitt
2023-10-05 22:42 ` Kees Cook [this message]
2023-10-06 9:37 ` Alexander Lobakin
2023-11-30 21:59 ` Kees Cook
2023-12-01 6:40 ` Jakub Kicinski
2023-12-01 18:19 ` Kees Cook
2023-12-07 19:51 ` Justin Stitt
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