From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759508AbcKCR4E (ORCPT ); Thu, 3 Nov 2016 13:56:04 -0400 Received: from thejh.net ([37.221.195.125]:35706 "EHLO thejh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754253AbcKCR4C (ORCPT ); Thu, 3 Nov 2016 13:56:02 -0400 Date: Thu, 3 Nov 2016 18:55:58 +0100 From: Jann Horn To: Kees Cook Cc: Lafcadio Wluiki , LKML , Andrew Morton , linux-arch , "kernel-hardening@lists.openwall.com" Subject: Re: [PATCH 2/2] procfs/tasks: add a simple per-task procfs hidepid= field Message-ID: <20161103175558.GA1177@laptop.thejh.net> References: <1478187038-19954-1-git-send-email-wluikil@gmail.com> <1478187038-19954-2-git-send-email-wluikil@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 03, 2016 at 10:12:55AM -0600, Kees Cook wrote: > On Thu, Nov 3, 2016 at 9:30 AM, Lafcadio Wluiki wrote: > > (Third, rebased submission, since first two submissions yielded no replies.) > > > > This adds a new per-task hidepid= flag that is honored by procfs when > > presenting /proc to the user, in addition to the existing hidepid= mount > > option. So far, hidepid= was exclusively a per-pidns setting. Locking > > down a set of processes so that they cannot see other user's processes > > without affecting the rest of the system thus currently requires > > creation of a private PID namespace, with all the complexity it brings, > > including maintaining a stub init process as PID 1 and losing the > > ability to see processes of the same user on the rest of the system. [...] > Since this adds a new prctl interface, it's best to Cc linux-arch > (which I added now). Please also CC linux-api for the next iteration, since this is a new userspace-facing API.