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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	[thread overview]
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	other threads:[~2018-01-04  0:19 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-22  0:12 [PATCH] Fix read buffer overflow in delta-ipc 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

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