Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933480AbbBBUiT (ORCPT ); Mon, 2 Feb 2015 15:38:19 -0500 Received: from mail-la0-f44.google.com ([209.85.215.44]:58119 "EHLO mail-la0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933326AbbBBUiQ (ORCPT ); Mon, 2 Feb 2015 15:38:16 -0500 MIME-Version: 1.0 In-Reply-To: <20150202180806.GE24351@ubuntumail> References: <54CFB9B8.8020701@schaufler-ca.com> <20150202180806.GE24351@ubuntumail> From: Andy Lutomirski Date: Mon, 2 Feb 2015 12:37:54 -0800 Message-ID: Subject: Re: [capabilities] Allow normal inheritance for a configurable set of capabilities To: Serge Hallyn Cc: Casey Schaufler , Christoph Lameter , Serge Hallyn , Jonathan Corbet , Aaron Jones , "Ted Ts'o" , LSM List , "linux-kernel@vger.kernel.org" , Andrew Morton Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1390 Lines: 26 On Mon, Feb 2, 2015 at 10:08 AM, Serge Hallyn wrote: > Quoting Casey Schaufler (casey@schaufler-ca.com): >> I'm game to participate in such an effort. The POSIX scheme >> is workable, but given that it's 20 years old and hasn't >> developed real traction it's hard to call it successful. > > Over the years we've several times discussed possible reasons for this > and how to help. I personally think it's two things: 1. lack of > toolchain and fs support. The fact that we cannot to this day enable > ping using capabilities by default because of cpio, tar and non-xattr > filesystems is disheartening. 2. It's hard for users and applications > to know what caps they need. yes the API is a bear to use, but we can > hide that behind fancier libraries. But using capabilities requires too > much in-depth knowledge of precisely what caps you might need for > whatever operations library may now do when you asked for something. None of this could address the problem here, though: if I hold a capability and I want to pass that capability to an exec'd helper, I shouldn't need the fs's help to do this. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/