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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=unavailable 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 ADB18C433E1 for ; Mon, 8 Jun 2020 11:53:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CEC12072F for ; Mon, 8 Jun 2020 11:53:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729642AbgFHLxA (ORCPT ); Mon, 8 Jun 2020 07:53:00 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:1314 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729535AbgFHLxA (ORCPT ); Mon, 8 Jun 2020 07:53:00 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 058BWOKU100710; Mon, 8 Jun 2020 07:52:57 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 31g59rbqjp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 08 Jun 2020 07:52:57 -0400 Received: from m0098413.ppops.net (m0098413.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 058BWJgl100209; Mon, 8 Jun 2020 07:52:57 -0400 Received: from ppma03ams.nl.ibm.com (62.31.33a9.ip4.static.sl-reverse.com [169.51.49.98]) by mx0b-001b2d01.pphosted.com with ESMTP id 31g59rbqj1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 08 Jun 2020 07:52:56 -0400 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 058BjE7m014959; Mon, 8 Jun 2020 11:52:55 GMT Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by ppma03ams.nl.ibm.com with ESMTP id 31g2s7uvm7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 08 Jun 2020 11:52:55 +0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 058Bqr3X6685134 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 8 Jun 2020 11:52:53 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 02110A405B; Mon, 8 Jun 2020 11:52:53 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5CF67A4051; Mon, 8 Jun 2020 11:52:52 +0000 (GMT) Received: from localhost.localdomain (unknown [9.85.178.150]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 8 Jun 2020 11:52:52 +0000 (GMT) Message-ID: <1591617171.4638.33.camel@linux.ibm.com> Subject: Re: [PATCH v2] IMA: Add audit log for failure conditions From: Mimi Zohar To: Lakshmi Ramasubramanian , paul@paul-moore.com Cc: linux-integrity@vger.kernel.org, linux-audit@redhat.com, linux-kernel@vger.kernel.org Date: Mon, 08 Jun 2020 07:52:51 -0400 In-Reply-To: <20200607221449.2837-1-nramas@linux.microsoft.com> References: <20200607221449.2837-1-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-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216,18.0.687 definitions=2020-06-08_07:2020-06-08,2020-06-08 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 mlxscore=0 impostorscore=0 clxscore=1015 adultscore=0 spamscore=0 phishscore=0 malwarescore=0 mlxlogscore=999 cotscore=-2147483648 bulkscore=0 suspectscore=2 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006080084 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Lakshmi, On Sun, 2020-06-07 at 15:14 -0700, Lakshmi Ramasubramanian wrote: > The final log statement in process_buffer_measurement() for failure > condition is at debug level. This does not log the message unless > the system log level is raised which would significantly increase > the messages in the system log. Change this log message to an audit > message for better triaging failures in the function. > > ima_alloc_key_entry() does not log a message for failure condition. > Add an audit message for failure condition in this function. > > Signed-off-by: Lakshmi Ramasubramanian Audit messages should be at a higher level.  For example, "hashing_error", "collect_data", "invalid_pcr".  In the "invalid_pcr" case, the audit log contains the reason - "ToMToU" or "open_writers" - as to why the measurement list doesn't match the PCR. Here you would want "measuring_keys", "measuring_boot_cmdline" with the reason it failed, not the function name "process_buffer_measurement". Userspace needs to be aware of the new audit messages.  Maybe include samples of them in the cover letter. thanks, Mimi > --- > security/integrity/ima/ima_main.c | 17 ++++++++++++----- > security/integrity/ima/ima_queue_keys.c | 4 ++++ > 2 files changed, 16 insertions(+), 5 deletions(-) > > diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c > index 800fb3bba418..1225198fceb1 100644 > --- a/security/integrity/ima/ima_main.c > +++ b/security/integrity/ima/ima_main.c > @@ -739,6 +739,7 @@ void process_buffer_measurement(const void *buf, int size, > int pcr, const char *keyring) > { > int ret = 0; > + const char *audit_cause = "ENOMEM"; > struct ima_template_entry *entry = NULL; > struct integrity_iint_cache iint = {}; > struct ima_event_data event_data = {.iint = &iint, > @@ -793,21 +794,27 @@ void process_buffer_measurement(const void *buf, int size, > iint.ima_hash->length = hash_digest_size[ima_hash_algo]; > > ret = ima_calc_buffer_hash(buf, size, iint.ima_hash); > - if (ret < 0) > + if (ret < 0) { > + audit_cause = "calc_buffer_hash"; > goto out; > + } > > ret = ima_alloc_init_template(&event_data, &entry, template); > - if (ret < 0) > + if (ret < 0) { > + audit_cause = "alloc_init_template"; > goto out; > + } > > ret = ima_store_template(entry, violation, NULL, buf, pcr); > - > - if (ret < 0) > + if (ret < 0) { > + audit_cause = "store_template"; > ima_free_template_entry(entry); > + } > > out: > if (ret < 0) > - pr_devel("%s: failed, result: %d\n", __func__, ret); > + integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, eventname, > + __func__, audit_cause, ret, 0); > > return; > } > diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c > index cb3e3f501593..fa606ce68f87 100644 > --- a/security/integrity/ima/ima_queue_keys.c > +++ b/security/integrity/ima/ima_queue_keys.c > @@ -68,6 +68,7 @@ static struct ima_key_entry *ima_alloc_key_entry(struct key *keyring, > size_t payload_len) > { > int rc = 0; > + const char *audit_cause = "ENOMEM"; > struct ima_key_entry *entry; > > entry = kzalloc(sizeof(*entry), GFP_KERNEL); > @@ -88,6 +89,9 @@ static struct ima_key_entry *ima_alloc_key_entry(struct key *keyring, > > out: > if (rc) { > + integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, > + keyring->description, __func__, > + audit_cause, rc, 0); > ima_free_key_entry(entry); > entry = NULL; > }