Re: [PATCH 07/44] kdbus: Fix comment on translation of caps between namespaces

["Hillf Danton" <hillf.zj@alibaba-inc.com>]

> @@ -730,15 +730,21 @@ static void kdbus_meta_export_caps(struct kdbus_meta_caps *out,
> 
>  	/*
>  	 * This translates the effective capabilities of 'cred' into the given
> -	 * user-namespace. If the given user-namespace is a child-namespace of
> -	 * the user-namespace of 'cred', the mask can be copied verbatim. If
> -	 * not, the mask is cleared.
> -	 * There's one exception: If 'cred' is the owner of any user-namespace
> -	 * in the path between the given user-namespace and the user-namespace
> -	 * of 'cred', then it has all effective capabilities set. This means,
> -	 * the user who created a user-namespace always has all effective
> -	 * capabilities in any child namespaces. Note that this is based on the
> -	 * uid of the namespace creator, not the task hierarchy.
> +	 * user namespace according to the following rules:
> +	 *
> +	 * - If 'cred' is a member of the given user namespace or any of its
> +	 *   parent user namespaces, the mask is copied verbatim. That is, if

Clearer/Better if "if not, the mask is cleared." is reserved.

> +	 *   a process has a capability in a user namespace, then it has it in
> +	 *   all child user namespaces too.
> +	 *
> +	 * - If the effective UID of 'cred' matches the owner of the given user
> +	 *   namespace or any of its parent user namespaces and 'cred' itself
> +	 *   resides in the parent of that user namespace which it owns, then
> +	 *   it has all effective capabilities set. This means that the user
> +	 *   who created a user namespace always has all effective capabilities
> +	 *   in all child namespaces while staying in the parent of the user
> +	 *   namespace which it owns. Note that this is based on the UID of the
> +	 *   namespace creator, not the task hierarchy.
>  	 */
>  	for (iter = user_ns; iter; iter = iter->parent) {
>  		if (iter == cred->user_ns) {
> --
> 1.8.3.1
>