Re: [PATCH v3] drivers/edac/edac_mc: Remove all strcpy() uses

From: Robert Richter <rric@kernel.org>
To: Len Baker <len.baker@gmx.com>
Cc: Joe Perches <joe@perches.com>, Borislav Petkov <bp@alien8.de>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Tony Luck <tony.luck@intel.com>,
	James Morse <james.morse@arm.com>,
	Kees Cook <keescook@chromium.org>,
	linux-hardening@vger.kernel.org, linux-edac@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] drivers/edac/edac_mc: Remove all strcpy() uses
Date: Mon, 9 Aug 2021 12:05:04 +0200	[thread overview]
Message-ID: <YRD90L6PMoVbbv+9@rric.localdomain> (raw)
In-Reply-To: <20210808112617.GA1927@titan>

On 08.08.21 13:26:17, Len Baker wrote:

> > Perhaps this should use scnprintf rather than strscpy
> > Something like:
> > 			n += scnprintf(buf + n, len - n, "%s",
> > 				       p == e->label ? dim->label : OTHER_LABEL);
> >
> In the first version [1] the scnprintf was used but Robert Richter don't
> see any benefit compared with the current implementation.
> 
> [1] https://lore.kernel.org/linux-hardening/20210725162954.9861-1-len.baker@gmx.com/

Reason is that there is the assumption that p must always point at the
end of the string and its trailing zero byte. I am not opposed using
the string function's return code instead of strlen() to get the
length. But why using formated output if strscpy() can be used?

-Robert