From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E108C432C3 for ; Thu, 14 Nov 2019 14:38:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6CBFA206D8 for ; Thu, 14 Nov 2019 14:38:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726598AbfKNOir (ORCPT ); Thu, 14 Nov 2019 09:38:47 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:30710 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726505AbfKNOiq (ORCPT ); Thu, 14 Nov 2019 09:38:46 -0500 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id xAEEadwo031831 for ; Thu, 14 Nov 2019 09:38:45 -0500 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2w976hvrbb-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 14 Nov 2019 09:38:44 -0500 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 14 Nov 2019 14:37:20 -0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xAEEbJpS39125238 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 14 Nov 2019 14:37:19 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 432A1AE045; Thu, 14 Nov 2019 14:37:19 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 073DFAE053; Thu, 14 Nov 2019 14:37:18 +0000 (GMT) Received: from localhost.localdomain (unknown [9.85.133.147]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 14 Nov 2019 14:37:17 +0000 (GMT) Subject: Re: [PATCH v7 4/5] IMA: Add support to limit measuring keys From: Mimi Zohar To: Lakshmi Ramasubramanian , dhowells@redhat.com, matthewgarrett@google.com, sashal@kernel.org, jamorris@linux.microsoft.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 14 Nov 2019 09:37:17 -0500 In-Reply-To: <20191114031202.18012-5-nramas@linux.microsoft.com> References: <20191114031202.18012-1-nramas@linux.microsoft.com> <20191114031202.18012-5-nramas@linux.microsoft.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.20.5 (3.20.5-1.fc24) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19111414-0008-0000-0000-0000032F0196 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19111414-0009-0000-0000-00004A4E10BB Message-Id: <1573742237.4793.30.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-11-14_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1910280000 definitions=main-1911140136 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On Wed, 2019-11-13 at 19:12 -0800, Lakshmi Ramasubramanian wrote: > +/** > + * ima_match_keyring - determine whether the keyring matches the measure rule > + * @rule: a pointer to a rule > + * @keyring: name of the keyring to match against the measure rule > + * > + * If the measure action for KEY_CHECK does not specify keyrings= > + * option then return true (Measure all keys). > + * Else, return true if the given keyring name is present in > + * the keyrings= option. False, otherwise. > + */ > +static bool ima_match_keyring(struct ima_rule_entry *rule, > + const char *keyring) > +{ > + if ((keyring == NULL) || (rule->keyrings == NULL) > + return true; If the policy requires matching a specific keyring, then the "keyring" needs to match.  The logic, here, isn't quite right. > + else > + return (strstr(rule->keyrings, keyring) != NULL);     if (rule->keyrings) {             if (!keyring)                     return false;             return (strstr(rule->keyrings, keyring) != NULL);     }     return true; Keyrings may be created by userspace with any name (e.g. foo, foobar, ...).  A keyring name might be a subset of another keyring name.  For example, with the policy "keyrings=foobar", keys being loaded on "foo" would also be measured.  Using strstr() will not achieve what is needed. Mimi > +} > + > /** > * ima_match_rules - determine whether an inode matches the measure rule. > * @rule: a pointer to a rule > @@ -364,18 +384,23 @@ int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event, > * @secid: the secid of the task to be validated > * @func: LIM hook identifier > * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC) > + * @keyring: keyring name to check in policy for KEY_CHECK func > * > * Returns true on rule match, false on failure. > */ > static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, > const struct cred *cred, u32 secid, > - enum ima_hooks func, int mask) > + enum ima_hooks func, int mask, > + const char *keyring) > { > int i; > > if ((func == KEXEC_CMDLINE) || (func == KEY_CHECK)) { > - if ((rule->flags & IMA_FUNC) && (rule->func == func)) > + if ((rule->flags & IMA_FUNC) && (rule->func == func)) { > + if (func == KEY_CHECK) > + return ima_match_keyring(rule, keyring); > return true; > + } > return false; > } > if ((rule->flags & IMA_FUNC) &&