Re: [XEN PATCH] tools/xl: Add device_model_stubdomain_init_seclabel option to xl.cfg

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 23/07/2021 05:47, Scott Davis wrote:
> diff --git a/tools/libs/light/libxl_create.c b/tools/libs/light/libxl_create.c
> index e356b2106d..a12da5531d 100644
> --- a/tools/libs/light/libxl_create.c
> +++ b/tools/libs/light/libxl_create.c
> @@ -1060,13 +1060,31 @@ int libxl__domain_config_setdefault(libxl__gc *gc,
>          char *s = d_config->b_info.device_model_ssid_label;
>          ret = libxl_flask_context_to_sid(ctx, s, strlen(s),
>                                           &d_config->b_info.device_model_ssidref);
> +        if (ret) {
> +            if (errno == ENOSYS) {
> +                LOGD(WARN, domid,
> +                     "XSM Disabled: device_model_stubdomain_init_seclabel not supported");
> +                ret = 0;

Surely this wants to be a hard error?

Not specifying a label is one thing, but specifying a label and having
it not take effect because code was compiled out of the hypervisor
sounds like a security hole.

I see this is a pattern copied from elsewhere, but it seems very short
signed.

~Andrew