Re: [Qemu-devel] [PATCH for-2.12 11/12] vhdx: Check for 4 GB maximum log size on creation

[Jeff Cody <jcody@redhat.com>]

On Tue, Mar 20, 2018 at 06:36:31PM +0100, Kevin Wolf wrote:
> It's unclear what the real maximum is, but we use an uint32_t to store
> the log size in vhdx_co_create(), so we should check that the given
> value fits in 32 bits.
> 

It's a uint32 in the on-disk header per spec, so I agree the implied max is
UINT32_MAX

Reviewed-by: Jeff Cody <jcody@redhat.com>

> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block/vhdx.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/block/vhdx.c b/block/vhdx.c
> index 0e48179b81..a1a0302799 100644
> --- a/block/vhdx.c
> +++ b/block/vhdx.c
> @@ -1829,6 +1829,10 @@ static int coroutine_fn vhdx_co_create(BlockdevCreateOptions *opts,
>      if (!vhdx_opts->has_log_size) {
>          log_size = DEFAULT_LOG_SIZE;
>      } else {
> +        if (vhdx_opts->log_size > UINT32_MAX) {
> +            error_setg(errp, "Log size must be smaller than 4 GB");
> +            return -EINVAL;
> +        }
>          log_size = vhdx_opts->log_size;
>      }
>      if (log_size < MiB || (log_size % MiB) != 0) {
> -- 
> 2.13.6
>