Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754860AbXFTOqA (ORCPT ); Wed, 20 Jun 2007 10:46:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753224AbXFTOpx (ORCPT ); Wed, 20 Jun 2007 10:45:53 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:47625 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753195AbXFTOpw (ORCPT ); Wed, 20 Jun 2007 10:45:52 -0400 Subject: Re: [RFC][Patch 2/3]integrity: IMA as an integrity service provider From: Mimi Zohar To: James Morris Cc: linux-kernel@vger.kernel.org, safford@watson.ibm.com, serue@linux.vnet.ibm.com, zohar@us.ibm.com, sailer@us.ibm.com In-Reply-To: References: <1182199326.8577.6.camel@localhost.localdomain> Content-Type: text/plain Date: Wed, 20 Jun 2007 10:48:43 -0400 Message-Id: <1182350923.5688.27.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.0.2 (2.0.2-27.rhel4.6) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1380 Lines: 37 On Tue, 2007-06-19 at 22:18 -0400, James Morris wrote: > On Mon, 18 Jun 2007, Mimi Zohar wrote: > > > > +/* what could we exclude > > + * - non-executable/non-library files ? > > + * - /proc /dev ? > > + * Only measure files opened for read-only or execute > > + */ > > +static int skip_measurement(struct inode *inode, int mask) > > +{ > > + if ((inode->i_sb->s_magic == PROC_SUPER_MAGIC) || > > + (inode->i_sb->s_magic == SYSFS_MAGIC)) { > > + return 1; /*can't measure */ > > + } > > I'm pretty sure you should skip measurement for many more pseudo > filesystems than this. The LSM module controls what is measured and should only be calling integrity_measure() for appropriate files. IBAC, for example, only calls integrity_measure() for executables from bprm_check_security() and file_mmap() and for other regular files from inode_permission(), based on the existence of the 'security.measure' xattr, which is labeled by a userspace application. The integrity provider, here, is just doing a quick sanity check, but I'll definitely make it more complete and fix the comment to make this clearer. Thanks! Mimi - 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/