Re: [PATCH] ieee802154: Replace strlcpy with strscpy

From: Stefan Schmidt <stefan@datenfreihafen.org>
To: Azeem Shaikh <azeemshaikh38@gmail.com>,
	Alexander Aring <alex.aring@gmail.com>,
	Miquel Raynal <miquel.raynal@bootlin.com>
Cc: linux-hardening@vger.kernel.org, linux-wpan@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	"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
Subject: Re: [PATCH] ieee802154: Replace strlcpy with strscpy
Date: Fri, 16 Jun 2023 23:32:48 +0200	[thread overview]
Message-ID: <6ec8cf42-aff0-a832-87f2-1526ff00c42d@datenfreihafen.org> (raw)
In-Reply-To: <20230613003326.3538391-1-azeemshaikh38@gmail.com>

Hello.

On 13.06.23 02:33, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> 
> Direct replacement is safe here since the return values
> from the helper macros are ignored by the callers.
> 
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
> 
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
> ---
>   net/ieee802154/trace.h |    2 +-
>   net/mac802154/trace.h  |    2 +-
>   2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/ieee802154/trace.h b/net/ieee802154/trace.h
> index e5d8439b9e45..c16db0b326fa 100644
> --- a/net/ieee802154/trace.h
> +++ b/net/ieee802154/trace.h
> @@ -13,7 +13,7 @@
>   
>   #define MAXNAME		32
>   #define WPAN_PHY_ENTRY	__array(char, wpan_phy_name, MAXNAME)
> -#define WPAN_PHY_ASSIGN	strlcpy(__entry->wpan_phy_name,	 \
> +#define WPAN_PHY_ASSIGN	strscpy(__entry->wpan_phy_name,	 \
>   				wpan_phy_name(wpan_phy), \
>   				MAXNAME)
>   #define WPAN_PHY_PR_FMT	"%s"
> diff --git a/net/mac802154/trace.h b/net/mac802154/trace.h
> index 689396d6c76a..1574ecc48075 100644
> --- a/net/mac802154/trace.h
> +++ b/net/mac802154/trace.h
> @@ -14,7 +14,7 @@
>   
>   #define MAXNAME		32
>   #define LOCAL_ENTRY	__array(char, wpan_phy_name, MAXNAME)
> -#define LOCAL_ASSIGN	strlcpy(__entry->wpan_phy_name, \
> +#define LOCAL_ASSIGN	strscpy(__entry->wpan_phy_name, \
>   				wpan_phy_name(local->hw.phy), MAXNAME)
>   #define LOCAL_PR_FMT	"%s"
>   #define LOCAL_PR_ARG	__entry->wpan_phy_name

This patch has been applied to the wpan tree and will be
part of the next pull request to net. Thanks!

regards
Stefan Schmidt