Re: [Qemu-devel] [PATCH 1/1] block/parallels: check new image size

["Denis V. Lunev" <den@openvz.org>]

On 07/27/2016 07:01 PM, Denis V. Lunev wrote:
> From: Klim Kireev <sproff@linux.com>
>
> Before this patch incorrect image could be created via qemu-img
> (Example: qemu-img create -f parallels -o size=4096T hack.img),
> incorrect images cannot be used due to overflow in main image structure.
>
> This patch add check of size in image creation.
>
> After reading size it compare it with UINT32_MAX * cluster_size.
>
> Signed-off-by: Klim Kireev <proffk@virtuozzo.mipt.com>
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> CC: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>   block/parallels.c | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/block/parallels.c b/block/parallels.c
> index 807a801..a0bc95b 100644
> --- a/block/parallels.c
> +++ b/block/parallels.c
> @@ -43,6 +43,7 @@
>   #define HEADER_MAGIC2 "WithouFreSpacExt"
>   #define HEADER_VERSION 2
>   #define HEADER_INUSE_MAGIC  (0x746F6E59)
> +#define MAX_PARALLELS_IMAGE_FACTOR (1ull << 32)
>   
>   #define DEFAULT_CLUSTER_SIZE 1048576        /* 1 MiB */
>   
> @@ -475,6 +476,10 @@ static int parallels_create(const char *filename, QemuOpts *opts, Error **errp)
>                             BDRV_SECTOR_SIZE);
>       cl_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE,
>                             DEFAULT_CLUSTER_SIZE), BDRV_SECTOR_SIZE);
> +    if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) {
> +        error_propagate(errp, local_err);
> +        return -E2BIG;
> +    }
>   
>       ret = bdrv_create_file(filename, opts, &local_err);
>       if (ret < 0) {
pls drop this. I have to resubmit it.