Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759899AbcKCSF1 (ORCPT ); Thu, 3 Nov 2016 14:05:27 -0400 Received: from mail-wm0-f46.google.com ([74.125.82.46]:38575 "EHLO mail-wm0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756863AbcKCSFY (ORCPT ); Thu, 3 Nov 2016 14:05:24 -0400 MIME-Version: 1.0 In-Reply-To: <20161103175558.GA1177@laptop.thejh.net> References: <1478187038-19954-1-git-send-email-wluikil@gmail.com> <1478187038-19954-2-git-send-email-wluikil@gmail.com> <20161103175558.GA1177@laptop.thejh.net> From: Kees Cook Date: Thu, 3 Nov 2016 12:05:22 -0600 X-Google-Sender-Auth: dKHaAsskSwFmt1mExv8yR3paokw Message-ID: Subject: Re: [PATCH 2/2] procfs/tasks: add a simple per-task procfs hidepid= field To: Jann Horn Cc: Lafcadio Wluiki , LKML , Andrew Morton , "kernel-hardening@lists.openwall.com" , linux-arch 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: 1180 Lines: 27 On Thu, Nov 3, 2016 at 11:55 AM, Jann Horn wrote: > 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. Oops, thank you. I meant linux-api, not linux-arch. :P -Kees -- Kees Cook Nexus Security