From patchwork Tue Aug 15 14:43:54 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mimi Zohar X-Patchwork-Id: 9901983 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C074C60230 for ; Tue, 15 Aug 2017 14:44:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B2D682888D for ; Tue, 15 Aug 2017 14:44:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A50A32886C; Tue, 15 Aug 2017 14:44:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2240E28892 for ; Tue, 15 Aug 2017 14:44:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752527AbdHOOom (ORCPT ); Tue, 15 Aug 2017 10:44:42 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:52910 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752516AbdHOOok (ORCPT ); Tue, 15 Aug 2017 10:44:40 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v7FEi2At139924 for ; Tue, 15 Aug 2017 10:44:40 -0400 Received: from e23smtp02.au.ibm.com (e23smtp02.au.ibm.com [202.81.31.144]) by mx0a-001b2d01.pphosted.com with ESMTP id 2cbttuy40w-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 15 Aug 2017 10:44:39 -0400 Received: from localhost by e23smtp02.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 16 Aug 2017 00:44:35 +1000 Received: from d23av06.au.ibm.com (d23av06.au.ibm.com [9.190.235.151]) by d23relay07.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v7FEiYYT41156674; Wed, 16 Aug 2017 00:44:34 +1000 Received: from d23av06.au.ibm.com (localhost [127.0.0.1]) by d23av06.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v7FEiXCa022203; Wed, 16 Aug 2017 00:44:34 +1000 Received: from localhost.localdomain.com ([9.80.85.193]) by d23av06.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id v7FEiIic021776; Wed, 16 Aug 2017 00:44:30 +1000 From: Mimi Zohar To: Christoph Hellwig , Al Viro Cc: Matthew Garrett , Mimi Zohar , James Morris , linux-fsdevel@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org Subject: [PATCH v6 3/6] ima: always measure and audit files in policy Date: Tue, 15 Aug 2017 10:43:54 -0400 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1502808237-2035-1-git-send-email-zohar@linux.vnet.ibm.com> References: <1502808237-2035-1-git-send-email-zohar@linux.vnet.ibm.com> X-TM-AS-MML: disable x-cbid: 17081514-0004-0000-0000-0000022A2561 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17081514-0005-0000-0000-00005E10CC04 Message-Id: <1502808237-2035-4-git-send-email-zohar@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-08-15_11:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1706020000 definitions=main-1708150247 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP All files matching a "measure" rule must be included in the IMA measurement list, even when the file hash cannot be calculated. Similarly, all files matching an "audit" rule must be audited, even when the file hash can not be calculated. The file data hash field contained in the IMA measurement list template data will contain 0's instead of the actual file hash digest. Signed-off-by: Mimi Zohar --- Changelog v6: - replace "?:" with if/then - annotate i_version usage - reword O_DIRECT comment Changelog v5: - Fail files opened O_DIRECT, but include attempt in measurement list. Changelog v4: - Based on both -EBADF and -EINVAL - clean up ima_collect_measurement() security/integrity/ima/ima_api.c | 67 +++++++++++++++++++++++-------------- security/integrity/ima/ima_crypto.c | 10 ++++++ security/integrity/ima/ima_main.c | 7 ++-- 3 files changed, 54 insertions(+), 30 deletions(-) diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index c2edba8de35e..1dee695642a4 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -199,42 +199,59 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, struct inode *inode = file_inode(file); const char *filename = file->f_path.dentry->d_name.name; int result = 0; + int length; + void *tmpbuf; + u64 i_version; struct { struct ima_digest_data hdr; char digest[IMA_MAX_DIGEST_SIZE]; } hash; - if (!(iint->flags & IMA_COLLECTED)) { - u64 i_version = file_inode(file)->i_version; + if (iint->flags & IMA_COLLECTED) + goto out; - if (file->f_flags & O_DIRECT) { - audit_cause = "failed(directio)"; - result = -EACCES; - goto out; - } + /* + * Dectecting file change is based on i_version. On filesystems + * which do not support i_version, support is limited to an initial + * measurement/appraisal/audit. + */ + i_version = file_inode(file)->i_version; + hash.hdr.algo = algo; - hash.hdr.algo = algo; - - result = (!buf) ? ima_calc_file_hash(file, &hash.hdr) : - ima_calc_buffer_hash(buf, size, &hash.hdr); - if (!result) { - int length = sizeof(hash.hdr) + hash.hdr.length; - void *tmpbuf = krealloc(iint->ima_hash, length, - GFP_NOFS); - if (tmpbuf) { - iint->ima_hash = tmpbuf; - memcpy(iint->ima_hash, &hash, length); - iint->version = i_version; - iint->flags |= IMA_COLLECTED; - } else - result = -ENOMEM; - } + /* Initialize hash digest to 0's in case of failure */ + memset(&hash.digest, 0, sizeof(hash.digest)); + + if (buf) + result = ima_calc_buffer_hash(buf, size, &hash.hdr); + else + result = ima_calc_file_hash(file, &hash.hdr); + + if (result && result != -EBADF && result != -EINVAL) + goto out; + + length = sizeof(hash.hdr) + hash.hdr.length; + tmpbuf = krealloc(iint->ima_hash, length, GFP_NOFS); + if (!tmpbuf) { + result = -ENOMEM; + goto out; } + + iint->ima_hash = tmpbuf; + memcpy(iint->ima_hash, &hash, length); + iint->version = i_version; + + /* Possibly temporary failure due to type of read (eg. O_DIRECT) */ + if (result != -EBADF && result != -EINVAL) + iint->flags |= IMA_COLLECTED; out: - if (result) + if (result) { + if (file->f_flags & O_DIRECT) + audit_cause = "failed(directio)"; + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename, "collect_data", audit_cause, result, 0); + } return result; } @@ -278,7 +295,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint, } result = ima_store_template(entry, violation, inode, filename, pcr); - if (!result || result == -EEXIST) { + if ((!result || result == -EEXIST) && !(file->f_flags & O_DIRECT)) { iint->flags |= IMA_MEASURED; iint->measured_pcrs |= (0x1 << pcr); } diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index 802d5d20f36f..a856d8c9c9f3 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -441,6 +441,16 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash) loff_t i_size; int rc; + /* + * For consistency, fail file's opened with the O_DIRECT flag on + * filesystems mounted with/without DAX option. + */ + if (file->f_flags & O_DIRECT) { + hash->length = hash_digest_size[ima_hash_algo]; + hash->algo = ima_hash_algo; + return -EINVAL; + } + i_size = i_size_read(file_inode(file)); if (ima_ahash_minsize && i_size >= ima_ahash_minsize) { diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 2aebb7984437..d23dfe6ede18 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -235,11 +235,8 @@ static int process_measurement(struct file *file, char *buf, loff_t size, hash_algo = ima_get_hash_algo(xattr_value, xattr_len); rc = ima_collect_measurement(iint, file, buf, size, hash_algo); - if (rc != 0) { - if (file->f_flags & O_DIRECT) - rc = (iint->flags & IMA_PERMIT_DIRECTIO) ? 0 : -EACCES; + if (rc != 0 && rc != -EBADF && rc != -EINVAL) goto out_digsig; - } if (!pathbuf) /* ima_rdwr_violation possibly pre-fetched */ pathname = ima_d_path(&file->f_path, &pathbuf, filename); @@ -247,7 +244,7 @@ static int process_measurement(struct file *file, char *buf, loff_t size, if (action & IMA_MEASURE) ima_store_measurement(iint, file, pathname, xattr_value, xattr_len, pcr); - if (action & IMA_APPRAISE_SUBMASK) + if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) rc = ima_appraise_measurement(func, iint, file, pathname, xattr_value, xattr_len, opened); if (action & IMA_AUDIT)