Re: [Qemu-block] [PATCH] qcow2: always initialize specific image info

[Denis V. Lunev]

On 12/07/2015 08:07 PM, Roman Kagan wrote:
> qcow2_get_specific_info() used to have a code path which would leave
> pointer to ImageInfoSpecificQCow2 uninitialized.
>
> We guess that it caused sporadic crashes on freeing an invalid pointer
> in response to "query-block" QMP command in
> visit_type_ImageInfoSpecificQCow2 with QapiDeallocVisitor.
>
> Although we have neither a solid proof nor a reproduction scenario,
> making sure the field is initialized appears a reasonable thing to do.
>
> Signed-off-by: Roman Kagan <address@hidden>
> ---
>   block/qcow2.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 88f56c8..67c9d3d 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -2739,7 +2739,7 @@ static ImageInfoSpecific 
> *qcow2_get_specific_info(BlockDriverState *bs)
>   
>       *spec_info = (ImageInfoSpecific){
>           .type  = IMAGE_INFO_SPECIFIC_KIND_QCOW2,
> -        .u.qcow2 = g_new(ImageInfoSpecificQCow2, 1),
> +        .u.qcow2 = g_new0(ImageInfoSpecificQCow2, 1),
>       };
>       if (s->qcow_version == 2) {
>           *spec_info->u.qcow2 = (ImageInfoSpecificQCow2){
Reviewed-by: Denis V. Lunev <address@hidden>