Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756058AbZKWWfT (ORCPT ); Mon, 23 Nov 2009 17:35:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755883AbZKWWfT (ORCPT ); Mon, 23 Nov 2009 17:35:19 -0500 Received: from rcsinet12.oracle.com ([148.87.113.124]:52322 "EHLO rgminet12.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755655AbZKWWfR (ORCPT ); Mon, 23 Nov 2009 17:35:17 -0500 Message-ID: <4B0B0DDB.4070504@oracle.com> Date: Mon, 23 Nov 2009 14:34:03 -0800 From: Randy Dunlap Organization: Oracle Linux Engineering User-Agent: Thunderbird 2.0.0.22 (X11/20090605) MIME-Version: 1.0 To: "Serge E. Hallyn" CC: James Morris , lkml , "Andrew G. Morgan" , Steve Grubb , linux-security-module@vger.kernel.org, Kees Cook , Andreas Gruenbacher , Michael Kerrisk , George Wilson , KaiGai Kohei Subject: Re: [PATCH] remove CONFIG_SECURITY_FILE_CAPABILITIES compile option References: <20091123222130.GA11325@us.ibm.com> In-Reply-To: <20091123222130.GA11325@us.ibm.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Source-IP: acsmt357.oracle.com [141.146.40.157] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090206.4B0B0DE0.0102:SCFMA4539814,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2190 Lines: 59 Serge E. Hallyn wrote: > As far as I know, all distros currently ship kernels with default > CONFIG_SECURITY_FILE_CAPABILITIES=y. Since having the option on > leaves a 'no_file_caps' option to boot without file capabilities, > the main reason to keep the option is that turning it off saves > you (on my s390x partition) 5k. In particular, vmlinux sizes > came to: > > without patch fscaps=n: 53598392 > without patch fscaps=y: 53603406 > with this patch applied: 53603342 > > with the security-next tree. > > Against this we must weigh the fact that there is no simple way for > userspace to figure out whether file capabilities are supported, > while things like per-process securebits, capability bounding > sets, and adding bits to pI if CAP_SETPCAP is in pE are not supported > with SECURITY_FILE_CAPABILITIES=n, leaving a bit of a problem for > applications wanting to know whether they can use them and/or why > something failed. > > It also adds another subtly different set of semantics which we must > maintain at the risk of severe security regressions. Hi, This is or is not the same security option that is referred to in (new:) http://bugzilla.kernel.org/show_bug.cgi?id=14675 ? > So this patch removes the SECURITY_FILE_CAPABILITIES compile > option. It drops the kernel size by about 50k over the stock > SECURITY_FILE_CAPABILITIES=y kernel, by removing the > cap_limit_ptraced_target() function. > > Changelog: > Nov 20: remove cap_limit_ptraced_target() as it's logic > was ifndef'ed. > > Signed-off-by: Serge E. Hallyn > Acked-by: Andrew G. Morgan" > --- > include/linux/capability.h | 2 - > include/linux/init_task.h | 4 -- > kernel/capability.c | 2 - > security/Kconfig | 9 ----- > security/commoncap.c | 72 +------------------------------------------ > 5 files changed, 2 insertions(+), 87 deletions(-) -- ~Randy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/