From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756003AbdKJEqt (ORCPT ); Thu, 9 Nov 2017 23:46:49 -0500 Received: from h2.hallyn.com ([78.46.35.8]:41074 "EHLO h2.hallyn.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755941AbdKJEqr (ORCPT ); Thu, 9 Nov 2017 23:46:47 -0500 Date: Thu, 9 Nov 2017 22:46:46 -0600 From: "Serge E. Hallyn" To: "Eric W. Biederman" Cc: Mahesh Bandewar =?utf-8?B?KOCkruCkueClh+CktiDgpKzgpILgpKHgpYfgpLXgpL4=?= =?utf-8?B?4KSwKQ==?= , "Serge E. Hallyn" , Christian Brauner , Boris Lukashev , Daniel Micay , Mahesh Bandewar , LKML , Netdev , Kernel-hardening , Linux API , Kees Cook , Eric Dumazet , David Miller Subject: Re: [kernel-hardening] Re: [PATCH resend 2/2] userns: control capabilities of some user namespaces Message-ID: <20171110044645.GA3694@mail.hallyn.com> References: <20171106233913.GA1518@mail.hallyn.com> <20171107032802.GA6669@mail.hallyn.com> <20171108190223.vdkyepcaegmub6le@gmail.com> <20171109032134.GA15666@mail.hallyn.com> <871sl7dsh8.fsf@xmission.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871sl7dsh8.fsf@xmission.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Eric W. Biederman (ebiederm@xmission.com): > single sandbox. I am not at all certain that the capabilities is the > proper place to limit code reachability. Right, I keep having this gut feeling that there is another way we should be doing that. Maybe based on ksplice or perf, or maybe more based on subsystems. And I hope someone pursues that. But I can't put my finger on it, and meanwhile the capability checks obviously *are* in fact gates... -serge