Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752152AbbLIQKx (ORCPT ); Wed, 9 Dec 2015 11:10:53 -0500 Received: from e28smtp04.in.ibm.com ([125.16.236.4]:54886 "EHLO e28smtp04.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751231AbbLIQKu (ORCPT ); Wed, 9 Dec 2015 11:10:50 -0500 X-IBM-Helo: d28dlp03.in.ibm.com X-IBM-MailFrom: zohar@linux.vnet.ibm.com X-IBM-RcptTo: keyrings@vger.kernel.org;linux-doc@vger.kernel.org;linux-kernel@vger.kernel.org;linux-security-module@vger.kernel.org Message-ID: <1449677438.2937.136.camel@linux.vnet.ibm.com> Subject: Re: [PATCH 2/2] keys, trusted: seal with a policy From: Mimi Zohar To: Jarkko Sakkinen Cc: David Howells , Peter Huewe , Marcel Selhorst , Jonathan Corbet , Jason Gunthorpe , James Morris , "Serge E. Hallyn" , "open list:KEYS-ENCRYPTED" , "open list:KEYS-ENCRYPTED" , "open list:DOCUMENTATION" , open list , "moderated list:TPM DEVICE DRIVER" Date: Wed, 09 Dec 2015 11:10:38 -0500 In-Reply-To: <20151209142420.GA8300@intel.com> References: <1447777643-10777-1-git-send-email-jarkko.sakkinen@linux.intel.com> <1447777643-10777-3-git-send-email-jarkko.sakkinen@linux.intel.com> <20151118070339.GA4942@intel.com> <20151207091202.GA15701@intel.com> <20151208110102.GA12339@intel.com> <20151208202423.GA4232@intel.com> <1449618977.2937.104.camel@linux.vnet.ibm.com> <20151209142420.GA8300@intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.11 (3.12.11-1.fc21) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15120916-0013-0000-0000-000008FA0E96 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3281 Lines: 79 On Wed, 2015-12-09 at 16:24 +0200, Jarkko Sakkinen wrote: > On Tue, Dec 08, 2015 at 06:56:17PM -0500, Mimi Zohar wrote: > > On Tue, 2015-12-08 at 22:24 +0200, Jarkko Sakkinen wrote: > > > On Tue, Dec 08, 2015 at 01:01:02PM +0200, Jarkko Sakkinen wrote: > > > > On Tue, Dec 08, 2015 at 09:35:05AM +1100, James Morris wrote: > > > > > On Mon, 7 Dec 2015, Jarkko Sakkinen wrote: > > > > > > > > > > > On Fri, Nov 20, 2015 at 01:34:35PM +1100, James Morris wrote: > > > > > > > On Wed, 18 Nov 2015, Jarkko Sakkinen wrote: > > > > > > > > > > > > > > > On Wed, Nov 18, 2015 at 11:21:01AM +1100, James Morris wrote: > > > > > > > > > On Tue, 17 Nov 2015, Jarkko Sakkinen wrote: > > > > > > > > > > > > > > > > > > > } > > > > > > > > > > break; > > > > > > > > > > + case Opt_policydigest: > > > > > > > > > > + if (!tpm2 || > > > > > > > > > > + strlen(args[0].from) != (2 * opt->digest_len)) > > > > > > > > > > + return -EINVAL; > > > > > > > > > > + kfree(opt->policydigest); > > > > > > > > > > + opt->policydigest = kzalloc(opt->digest_len, > > > > > > > > > > + GFP_KERNEL); > > > > You're allocating the exact amount of storage needed. There's no reason > > to use kzalloc here or elsewhere in the patch. > > Yup. I'll change this. > > > > > > > > > > > > > > > > > > > Is it correct to kfree opt->policydigest here before allocating it? > > > > > > > > > > > > > > > > I think so. The same option might be encountered multiple times. > > > > > > > > > > > > > > This would surely signify an error? > > > > > > > > > > > > I'm following the semantics of other options. That's why I implemented > > > > > > it that way for example: > > > > > > > > > > > > keyctl add trusted kmk "new 32 keyhandle=0x80000000 keyhandle=0x80000000" > > > > > > > > > > > > is perfectly OK. I just thought that it'd be more odd if this option > > > > > > behaved in a different way... > > > > > > > > > > It seems broken to me -- if you're messing up keyctl commands you might > > > > > want to know about it, but we should remain consistent. > > > > > > > > So should I return error if policyhandle/digest appears a second time? I > > > > agree that it'd be better to return -EINVAL. > > > > > > > > The existing behavior is such that any option can appear multiple times > > > > and I chose to be consistent with that. > > > > > > Mimi, David? > > > > I don't have a problem with changing the existing behavior to allow the > > options to be specified only once. > > I don't think this patch is right place to change the behavior as it > should be done for other options too. I think the easiest way of checking if a token has already been seen would be to define a flag and use test_and_set_bit(token, ) after the following code snippet. while ((p = strsep(&c, " \t"))) { if (*p == '\0' || *p == ' ' || *p == '\t') continue; token = match_token(p, key_tokens, args); Having a separate patch is probably a good idea. 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/