linux-kernel - Re: [PATCH 10/17] delta: Fix buffer overrun in delta_ipc

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Date:   Tue, 2 Apr 2019 09:56:58 +0000
From:   Hugues FRUCHET <hugues.fruchet@...com>
To:     Andi Kleen <andi@...stfloor.org>
CC:     "x86@...nel.org" <x86@...nel.org>,
        "akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Andi Kleen <ak@...ux.intel.com>,
        "mchehab@...pensource.com" <mchehab@...pensource.com>
Subject: Re: [PATCH 10/17] delta: Fix buffer overrun in delta_ipc_open

Hi Andi,

So do both, memset then strscpy:

+	memset(msg.name, 0, sizeof(msg.name));
+	if (strscpy(msg.name, name, sizeof(msg.name)) <= 0)
+         goto err;

BR,
Hugues.

On 4/1/19 6:54 PM, Andi Kleen wrote:
> On Mon, Apr 01, 2019 at 01:37:56PM +0000, Hugues FRUCHET wrote:
>> Hi Andi,
>>
>> We have already discussed about that here:
>> https://lore.kernel.org/patchwork/patch/866406/
>>
>> Now that strscpy is largely deployed within kernel, could you retest
>> with the change I suggested ?
> 
> strscpy is not the correct fix because it leaks uninitialized memory
> to the receiver.  You need the memset.
> 
> -Andi
>