Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754304AbWKHFcd (ORCPT ); Wed, 8 Nov 2006 00:32:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754306AbWKHFcd (ORCPT ); Wed, 8 Nov 2006 00:32:33 -0500 Received: from e35.co.us.ibm.com ([32.97.110.153]:56788 "EHLO e35.co.us.ibm.com") by vger.kernel.org with ESMTP id S1754297AbWKHFcc (ORCPT ); Wed, 8 Nov 2006 00:32:32 -0500 Date: Tue, 7 Nov 2006 23:32:29 -0600 From: "Serge E. Hallyn" To: "Serge E. Hallyn" , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, Stephen Smalley , James Morris , chris friedhoff , Chris Wright , Andrew Morton Subject: Re: [PATCH 1/1] security: introduce file posix caps Message-ID: <20061108053229.GA23210@sergelap.austin.ibm.com> References: <20061107034550.GA13693@sergelap.austin.ibm.com> <20061107215444.GO30208@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061107215444.GO30208@suse.de> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2696 Lines: 92 Quoting Seth Arnold (seth.arnold@suse.de): > On Mon, Nov 06, 2006 at 09:45:50PM -0600, Serge E. Hallyn wrote: > > #define CAP_AUDIT_CONTROL 30 > > > > +#define CAP_NUMCAPS 31 > > [...] > > > +struct vfs_cap_data_struct { > > + __u32 version; > > + __u32 effective; > > + __u32 permitted; > > + __u32 inheritable; > > +}; > > [...] > > > +static int check_cap_sanity(struct vfs_cap_data_struct *cap) > > +{ > > + int i; > > + > > + if (cap->version != _LINUX_CAPABILITY_VERSION) > > + return -EPERM; > > + > > + for (i=CAP_NUMCAPS; ieffective); i++) { > > + if (cap->effective & CAP_TO_MASK(i)) > > + return -EPERM; > > + } > > + for (i=CAP_NUMCAPS; ipermitted); i++) { > > + if (cap->permitted & CAP_TO_MASK(i)) > > + return -EPERM; > > + } > > + for (i=CAP_NUMCAPS; iinheritable); i++) { > > + if (cap->inheritable & CAP_TO_MASK(i)) > > + return -EPERM; > > + } > > + > > + return 0; > > +} > > for (i=31; i<4; i++) ... > > I'm not sure this checks what you think it checks? :) Thanks again for catching this. Here is the obvious patch. Hopefully I have it right this time. >From b91c46589b13bab78ddf431245a7ecbd59bcf2fd Mon Sep 17 00:00:00 2001 From: Serge E. Hallyn Date: Tue, 7 Nov 2006 23:16:06 -0600 Subject: [PATCH 1/1] fscaps: fix cap sanity check When checking for valid capabilities on files, we want to make sure that unused bits are not set. Fix the calculation of the highest bit checked. Signed-off-by: Serge E. Hallyn --- security/commoncap.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/security/commoncap.c b/security/commoncap.c index 6a0d033..6f5e46c 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -133,15 +133,15 @@ static int check_cap_sanity(struct vfs_c if (cap->version != _LINUX_CAPABILITY_VERSION) return -EPERM; - for (i=CAP_NUMCAPS; ieffective); i++) { + for (i=CAP_NUMCAPS; i<8*sizeof(cap->effective); i++) { if (cap->effective & CAP_TO_MASK(i)) return -EPERM; } - for (i=CAP_NUMCAPS; ipermitted); i++) { + for (i=CAP_NUMCAPS; i<8*sizeof(cap->permitted); i++) { if (cap->permitted & CAP_TO_MASK(i)) return -EPERM; } - for (i=CAP_NUMCAPS; iinheritable); i++) { + for (i=CAP_NUMCAPS; i<8*sizeof(cap->inheritable); i++) { if (cap->inheritable & CAP_TO_MASK(i)) return -EPERM; } -- 1.4.3.3 - 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/