LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Andi Kleen <andi@firstfloor.org>
To: Hugues FRUCHET <hugues.fruchet@st.com>
Cc: Andi Kleen <andi@firstfloor.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	Andi Kleen <ak@linux.intel.com>,
	"mchehab@s-opensource.com" <mchehab@s-opensource.com>
Subject: Re: [PATCH] Fix read buffer overflow in delta-ipc
Date: Wed, 3 Jan 2018 16:19:34 -0800
Message-ID: <20180104001933.3jcawm7eqrfgmvr7@two.firstfloor.org> (raw)
In-Reply-To: <74958ca0-e78e-0505-f738-1ddda50d8ead@st.com>

On Wed, Jan 03, 2018 at 09:40:04AM +0000, Hugues FRUCHET wrote:
> Hi Andi,
> Thanks for the patch but I would suggest to use strlcpy instead, this 
> will guard msg.name overwriting and add the NULL termination in case
> of truncation:
> -	memcpy(msg.name, name, sizeof(msg.name));
> -	msg.name[sizeof(msg.name) - 1] = 0;
> +	strlcpy(msg.name, name, sizeof(msg.name));

I'm not an expert on your setup, but it seems strlcpy would leak some
uninitialized stack data over your ipc mechanism. strclpy doesn't pad the
data. If the IPC is a security boundary that would be a security bug.

So I think the original patch is better than strlcpy.

-Andi

  reply index

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-22  0:12 Andi Kleen
2018-01-03  9:40 ` Hugues FRUCHET
2018-01-04  0:19   ` Andi Kleen [this message]
2018-01-04  9:53     ` Hugues FRUCHET

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180104001933.3jcawm7eqrfgmvr7@two.firstfloor.org \
    --to=andi@firstfloor.org \
    --cc=ak@linux.intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=hugues.fruchet@st.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mchehab@s-opensource.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org linux-kernel@archiver.kernel.org
	public-inbox-index lkml


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox