From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id D86799000BD for ; Mon, 19 Sep 2011 16:37:52 -0400 (EDT) Subject: Re: [kernel-hardening] Re: [RFC PATCH 2/2] mm: restrict access to /proc/slabinfo In-Reply-To: Your message of "Mon, 19 Sep 2011 15:02:34 CDT." From: Valdis.Kletnieks@vt.edu References: <20110910164134.GA2442@albatros> <20110914192744.GC4529@outflux.net> <20110918170512.GA2351@albatros> <20110919144657.GA5928@albatros> <20110919155718.GB16272@albatros> <20110919161837.GA2232@albatros> <20110919173539.GA3751@albatros> <14587.1316462369@turing-police.cc.vt.edu> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1316464598_2864P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Mon, 19 Sep 2011 16:36:38 -0400 Message-ID: <15820.1316464598@turing-police.cc.vt.edu> Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Vasiliy Kulikov , Pekka Enberg , Andrew Morton , kernel-hardening@lists.openwall.com, Kees Cook , Cyrill Gorcunov , Al Viro , Christoph Lameter , Matt Mackall , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dan Rosenberg , Theodore Tso , Alan Cox , Jesper Juhl , Linus Torvalds --==_Exmh_1316464598_2864P Content-Type: text/plain; charset=us-ascii On Mon, 19 Sep 2011 15:02:34 CDT, Christoph Lameter said: > On Mon, 19 Sep 2011, Valdis.Kletnieks@vt.edu wrote: > > > On Mon, 19 Sep 2011 12:51:10 CDT, Christoph Lameter said: > > > > > IMHO a restriction of access to slab statistics is reasonable in a > > > hardened environment. Make it dependent on CONFIG_SECURITY or some such > > > thing? > > > > Probably need to invent a separate Kconfig variable - CONFIG_SECURITY > > is probably a way-too-big hammer for this nail. I can see lots of systems > > that want to enable that, but won't want to tighten access to slab. > > There is already CONFIG_SECURITY_DMESG_RESTRICT. Generalize that setting > to include all sorts of other kernel statistics? The question becomes "What are the chances that a given site either will or will not agree with using the same setting for all things aggregated under the same option". I could probably make a good case for a flag called CONFIG_SECURITY_INFOLEAK_RESTRICT that would be a switch for "standard perms or root only" for all info-leaking files under /proc and /sys. The problem is that dmesg has *other* info-leakage issues - but it's not internal kernel state, it's stuff like ipfilter messages and potentially Selinux messages if auditd isn't running, and of late things like systemd and crond like to stick crap in there as well. --==_Exmh_1316464598_2864P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFOd6fWcC3lWbTT17ARAhrsAJsFAFIUkT5hViVm7WwhRAKVtg0RtgCglQCA kuFRA1R/2evUZwBiwJgH4HY= =cav9 -----END PGP SIGNATURE----- --==_Exmh_1316464598_2864P-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org