Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Message-ID: <ff02ffffdc130a772c01ec0edbf8d1e684b0730a.camel@perches.com>
Subject: Re: [PATCH v3] drivers/edac/edac_mc: Remove all strcpy() uses
From:   Joe Perches <joe@perches.com>
To:     Len Baker <len.baker@gmx.com>, Borislav Petkov <bp@alien8.de>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Tony Luck <tony.luck@intel.com>,
        James Morse <james.morse@arm.com>,
        Robert Richter <rric@kernel.org>
Cc:     Kees Cook <keescook@chromium.org>, linux-hardening@vger.kernel.org,
        linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Sat, 07 Aug 2021 10:09:35 -0700
In-Reply-To: <20210807155957.10069-1-len.baker@gmx.com>
References: <20210807155957.10069-1-len.baker@gmx.com>
Content-Type: text/plain; charset="ISO-8859-1"
User-Agent: Evolution 3.40.0-1 
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

On Sat, 2021-08-07 at 17:59 +0200, Len Baker wrote:
> strcpy() performs no bounds checking on the destination buffer. This
> could result in linear overflows beyond the end of the buffer, leading
> to all kinds of misbehaviors. The safe replacement is strscpy().

Probably better to change the commit subject to something like
what is generally used by the subsystem.

Maybe:
	EDAC/mc: Convert strcpy to strscpy
or
	EDAC/mc: Prefer strscpy over strcpy

and also:

> diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
[]
> @@ -1113,11 +1115,11 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
> ?			p = e->label;
> ?			*p = '\0';
> ?		} else {
> -			if (p != e->label) {
> -				strcpy(p, OTHER_LABEL);
> -				p += strlen(OTHER_LABEL);
> -			}
> -			strcpy(p, dimm->label);
> +			const char *text = (p != e->label) ? OTHER_LABEL :
> +				dimm->label;
> +
> +			strscpy(p, text, len);
> +			len -= strlen(p);
> ?			p += strlen(p);

Perhaps this should use scnprintf rather than strscpy
Something like:
			n += scnprintf(buf + n, len - n, "%s",
				       p == e->label ? dim->label : OTHER_LABEL);