From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752515Ab1KGUVO (ORCPT ); Mon, 7 Nov 2011 15:21:14 -0500 Received: from mail-bw0-f46.google.com ([209.85.214.46]:50027 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750957Ab1KGUVN (ORCPT ); Mon, 7 Nov 2011 15:21:13 -0500 Date: Tue, 8 Nov 2011 00:19:08 +0400 From: Vasiliy Kulikov To: Valdis.Kletnieks@vt.edu Cc: "H. Peter Anvin" , linux-kernel@vger.kernel.org, Alexey Dobriyan , Andrew Morton , linux-security-module@vger.kernel.org, Linus Torvalds , kernel-hardening@lists.openwall.com Subject: Re: [PATCH] proc: restrict access to /proc/interrupts Message-ID: <20111107201908.GA5827@albatros> References: <20111107174522.GA2317@albatros> <9718.1320689192@turing-police.cc.vt.edu> <20111107190112.GA3732@albatros> <4EB82F08.8060209@zytor.com> <14202.1320696659@turing-police.cc.vt.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <14202.1320696659@turing-police.cc.vt.edu> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 07, 2011 at 15:10 -0500, Valdis.Kletnieks@vt.edu wrote: > On Mon, 07 Nov 2011 11:18:32 PST, "H. Peter Anvin" said: > > > I would like to propose that we add a mount option to procfs, and > > possibly sysfs, called, say, admingrp. These kinds of files then get > > restricted to the admingrp (defaulting to gid 0 if no admingrp is > > provided). Historically on Unix there has been a group of people > > (usually "adm", but sometimes "log") who are allowed to read (but not > > write) the log files, which also contains potentially sensitive information. > > Probably should be a two part - mount with 'gid=NNN', and then a > perm=027 or whatever, to be treated similar to a umask. So 027 > would allow root to do anything, would disable write for the gid= group, > and turn it off completely for others. Less paranoid sites could mount > it with perm=002. > > Does that cover most of the use cases? At the time of Linux 2.0-2.4 in Owl patch there was a plain on/off configure option - 022 / 066 umask. Currently procfs restriction is implemented in Grsecurity with the same all-or-nothing approach. Brad Spengler told me that there were no user complains about the lack of flexibility :-) So, I agree that we don't need anything more complex. Thanks, -- Vasiliy Kulikov http://www.openwall.com - bringing security into open computing environments