On 04/28/2013 04:32 PM, Michael S. Tsirkin wrote:
> On Fri, Apr 26, 2013 at 04:34:03PM +0800, Jason Wang wrote:
>> virtio-rng-ccw has zero config length, so we need validate the config length
>> before trying to access it. Otherwise we may crash since vdev->config is
>> NULL.
>>
>> Cc: Cornelia Huck <cornelia.h...@de.ibm.com>
>> Cc: Richard Henderson <r...@twiddle.net>
>> Cc: Alexander Graf <ag...@suse.de>
>> Signed-off-by: Jason Wang <jasow...@redhat.com>
> The real problem is dev->vdev->get_config being NULL,
> isn't it? So why not validate it and be done with it?
Ok, this looks more clear. Will do it in V2.
>> ---
>> hw/s390x/virtio-ccw.c | 4 ++--
>> 1 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
>> index 56539d3..8d0dff5 100644
>> --- a/hw/s390x/virtio-ccw.c
>> +++ b/hw/s390x/virtio-ccw.c
>> @@ -260,7 +260,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
>> }
>> }
>> len = MIN(ccw.count, dev->vdev->config_len);
>> - if (!ccw.cda) {
>> + if (!ccw.cda || !len) {
>> ret = -EFAULT;
>> } else {
>> dev->vdev->get_config(dev->vdev, dev->vdev->config);
>> @@ -279,7 +279,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
>> }
>> len = MIN(ccw.count, dev->vdev->config_len);
>> hw_len = len;
>> - if (!ccw.cda) {
>> + if (!ccw.cda || !len) {
>> ret = -EFAULT;
>> } else {
>> config = cpu_physical_memory_map(ccw.cda, &hw_len, 0);
>> --
>> 1.7.1
