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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 96708C04AB6 for ; Tue, 28 May 2019 14:10:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6343F206E0 for ; Tue, 28 May 2019 14:10:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726562AbfE1OKK (ORCPT ); Tue, 28 May 2019 10:10:10 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36074 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726371AbfE1OKK (ORCPT ); Tue, 28 May 2019 10:10:10 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4SE9p2P065728 for ; Tue, 28 May 2019 10:10:08 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0b-001b2d01.pphosted.com with ESMTP id 2ss5ktjthh-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 28 May 2019 10:10:00 -0400 Received: from localhost by e06smtp01.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) Tue, 28 May 2019 15:09:34 +0100 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4SE9XAf34406474 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 28 May 2019 14:09:33 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 606A0AE053; Tue, 28 May 2019 14:09:33 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4FED4AE051; Tue, 28 May 2019 14:09:31 +0000 (GMT) Received: from localhost.localdomain (unknown [9.80.109.224]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 28 May 2019 14:09:31 +0000 (GMT) Subject: Re: [PATCH v10 12/12] ima: Store the measurement again when appraising a modsig From: Mimi Zohar To: Thiago Jung Bauermann , linux-integrity@vger.kernel.org Cc: linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , David Howells , David Woodhouse , Jessica Yu , Herbert Xu , "David S. Miller" , Jonathan Corbet , "AKASHI, Takahiro" Date: Tue, 28 May 2019 10:09:20 -0400 In-Reply-To: <20190418035120.2354-13-bauerman@linux.ibm.com> References: <20190418035120.2354-1-bauerman@linux.ibm.com> <20190418035120.2354-13-bauerman@linux.ibm.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: 19052814-4275-0000-0000-0000033962A2 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19052814-4276-0000-0000-000038490AD0 Message-Id: <1559052560.4090.14.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-28_06:,, 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=8.0.1-1810050000 definitions=main-1905280092 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Hi Thiago, On Thu, 2019-04-18 at 00:51 -0300, Thiago Jung Bauermann wrote: > If the IMA template contains the "modsig" or "d-modsig" field, then the > modsig should be added to the measurement list when the file is appraised. > > And that is what normally happens, but if a measurement rule caused a file > containing a modsig to be measured before a different rule causes it to be > appraised, the resulting measurement entry will not contain the modsig > because it is only fetched during appraisal. When the appraisal rule > triggers, it won't store a new measurement containing the modsig because > the file was already measured. > > We need to detect that situation and store an additional measurement with > the modsig. This is done by adding an IMA_MEASURE action flag if we read a > modsig and the IMA template contains a modsig field. With the new per policy rule "template" support being added, this patch needs to be modified so that the per policy "template" format is checked.  ima_template_has_modsig() should be called with the template_desc being used. thanks, Mimi > diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c > index 8e6475854351..f91ed4189f98 100644 > --- a/security/integrity/ima/ima_main.c > +++ b/security/integrity/ima/ima_main.c > @@ -282,9 +282,17 @@ static int process_measurement(struct file *file, const struct cred *cred, > /* read 'security.ima' */ > xattr_len = ima_read_xattr(file_dentry(file), &xattr_value); > > - /* Read the appended modsig if allowed by the policy. */ > - if (iint->flags & IMA_MODSIG_ALLOWED) > - ima_read_modsig(func, buf, size, &modsig); > + /* > + * Read the appended modsig, if allowed by the policy, and allow > + * an additional measurement list entry, if needed, based on the > + * template format. > + */ > + if (iint->flags & IMA_MODSIG_ALLOWED) { > + rc = ima_read_modsig(func, buf, size, &modsig); > + > + if (!rc && ima_template_has_modsig()) > + action |= IMA_MEASURE; > + } >