From mboxrd@z Thu Jan  1 00:00:00 1970
From: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Subject: Re: [PATCH v5 29/33] nvdimm acpi: support Get
 Namespace Label Data function
Date: Thu, 29 Oct 2015 10:25:00 +0800
Message-ID: <5631837C.60503@linux.intel.com>
References: <1446071191-62591-1-git-send-email-guangrong.xiao@linux.intel.com>
	<1446071191-62591-30-git-send-email-guangrong.xiao@linux.intel.com>
	<20151028164645.GC1925@stefanha-x1.localdomain>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Cc: ehabkost@redhat.com, kvm@vger.kernel.org, mst@redhat.com, gleb@kernel.org,
	mtosatti@redhat.com, qemu-devel@nongnu.org, imammedo@redhat.com,
	pbonzini@redhat.com, dan.j.williams@intel.com, rth@twiddle.net
To: Stefan Hajnoczi <stefanha@redhat.com>
Return-path: <qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org>
In-Reply-To: <20151028164645.GC1925@stefanha-x1.localdomain>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org
Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org
List-Id: kvm.vger.kernel.org



On 10/29/2015 12:46 AM, Stefan Hajnoczi wrote:
> On Wed, Oct 28, 2015 at 10:26:27PM +0000, Xiao Guangrong wrote:
>> +static void nvdimm_dsm_func_get_label_data(NVDIMMDevice *nvdimm,
>> +                                           nvdimm_dsm_in *in, GArray *out)
>> +{
>> +    NVDIMMClass *nvc = NVDIMM_GET_CLASS(nvdimm);
>> +    nvdimm_func_in_get_label_data *get_label_data = &in->func_get_label_data;
>> +    void *buf;
>> +    uint32_t status = NVDIMM_DSM_STATUS_SUCCESS;
>> +
>> +    le32_to_cpus(&get_label_data->offset);
>> +    le32_to_cpus(&get_label_data->length);
>> +
>> +    nvdimm_debug("Read Label Data: offset %#x length %#x.\n",
>> +                 get_label_data->offset, get_label_data->length);
>> +
>> +    if (nvdimm->label_size < get_label_data->offset + get_label_data->length) {
>
> Integer overflow isn't handled here and it's unclear if that can cause
> problems later on.  It's safest to catch it right away instead of
> relying on nvc->read_label_data() to check again.
>

Good catch, Stefan! I will fix it by adding a additional check:

if (get_label_data->offset + get_label_data->length > get_label_data->offset) {
	nvdimm_debug("offset ％#x + length %#x overflowed.\n");
	status = NVDIMM_DSM_DEV_STATUS_INVALID_PARAS;
	goto exit;
}