[ckrm-tech] [PATCH 7/7] containers (V7): Container interface to nsproxy subsystem

[Srivatsa Vaddagiri]

On Mon, Feb 12, 2007 at 12:15:28AM -0800, menage at google.com wrote:
> +/*
> + * Rules: you can only create a container if
> + *     1. you are capable(CAP_SYS_ADMIN)
> + *     2. the target container is a descendant of your own container
> + */
> +static int ns_create(struct container_subsys *ss, struct container *cont)
> +{
> +	struct nscont *ns;
> +
> +	if (!capable(CAP_SYS_ADMIN))
> +		return -EPERM;

Does this check break existing namespace semantics in a subtle way?
It now requires that unshare() of namespaces by any task requires
CAP_SYS_ADMIN capabilities.

clone(.., CLONE_NEWUTS, ..)->copy_namespaces()->ns_container_clone()->
	->container_clone()-> .. -> container_create() -> ns_create()

Earlier, one could unshare his uts namespace w/o CAP_SYS_ADMIN
capabilities. Now it is required. Is that fine? Don't know.

I feel we can avoid this check totally and let the directory permissions
take care of these checks.

Serge, what do you think?

-- 
Regards,
vatsa