From patchwork Wed May 23 00:12:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thiago Jung Bauermann X-Patchwork-Id: 10419931 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 08EA46016C for ; Wed, 23 May 2018 00:29:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ED64328DAD for ; Wed, 23 May 2018 00:29:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E225628DC3; Wed, 23 May 2018 00:29:34 +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=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable 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 6F5CF28DAD for ; Wed, 23 May 2018 00:29:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753708AbeEWA3d (ORCPT ); Tue, 22 May 2018 20:29:33 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:47914 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753684AbeEWA0M (ORCPT ); Tue, 22 May 2018 20:26:12 -0400 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w4N0KRCI104661 for ; Tue, 22 May 2018 20:26:12 -0400 Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) by mx0a-001b2d01.pphosted.com with ESMTP id 2j4qqveeru-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 22 May 2018 20:26:12 -0400 Received: from localhost by e37.co.us.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, 22 May 2018 18:26:05 -0600 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w4N0EfYJ35389638 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 23 May 2018 00:14:41 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C2C4EAC041; Tue, 22 May 2018 20:16:10 -0400 (EDT) Received: from morokweng.localdomain.com (unknown [9.80.193.181]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP id 03982AC03A; Tue, 22 May 2018 20:16:04 -0400 (EDT) From: Thiago Jung Bauermann To: 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-kernel@vger.kernel.org, Mimi Zohar , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , David Howells , David Woodhouse , Jessica Yu , Herbert Xu , "David S. Miller" , "AKASHI, Takahiro" , Thiago Jung Bauermann Subject: [PATCH v7 04/14] integrity: Introduce struct evm_xattr Date: Tue, 22 May 2018 21:12:43 -0300 X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180523001253.15247-1-bauerman@linux.ibm.com> References: <20180523001253.15247-1-bauerman@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18052300-0024-0000-0000-0000187696E3 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009068; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000261; SDB=6.01036241; UDB=6.00530093; IPR=6.00815369; MB=3.00021248; MTD=3.00000008; XFM=3.00000015; UTC=2018-05-23 00:26:09 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18052300-0025-0000-0000-0000501C2F47 Message-Id: <20180523001253.15247-5-bauerman@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-05-22_09:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1805230002 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Even though struct evm_ima_xattr_data includes a fixed-size array to hold a SHA1 digest, most of the code ignores the array and uses the struct to mean "type indicator followed by data of unspecified size" and tracks the real size of what the struct represents in a separate length variable. The only exception to that is the EVM code, which correctly uses the definition of struct evm_ima_xattr_data. So make this explicit in the code by removing the length specification from the array in struct evm_ima_xattr_data. Also, change the name of the element from digest to data since in most places the array doesn't hold a digest. A separate struct evm_xattr is introduced, with the original definition of evm_ima_xattr_data to be used in the places that actually expect that definition. Signed-off-by: Thiago Jung Bauermann --- security/integrity/evm/evm_crypto.c | 4 ++-- security/integrity/evm/evm_main.c | 10 +++++----- security/integrity/ima/ima_appraise.c | 7 ++++--- security/integrity/integrity.h | 5 +++++ 4 files changed, 16 insertions(+), 10 deletions(-) diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c index 494da5fcc092..c03ebb0c20b4 100644 --- a/security/integrity/evm/evm_crypto.c +++ b/security/integrity/evm/evm_crypto.c @@ -302,7 +302,7 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name, const char *xattr_value, size_t xattr_value_len) { struct inode *inode = d_backing_inode(dentry); - struct evm_ima_xattr_data xattr_data; + struct evm_xattr xattr_data; int rc = 0; /* @@ -318,7 +318,7 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name, rc = evm_calc_hmac(dentry, xattr_name, xattr_value, xattr_value_len, xattr_data.digest); if (rc == 0) { - xattr_data.type = EVM_XATTR_HMAC; + xattr_data.data.type = EVM_XATTR_HMAC; rc = __vfs_setxattr_noperm(dentry, XATTR_NAME_EVM, &xattr_data, sizeof(xattr_data), 0); diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index f9eff5041e4c..65f9578be058 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -134,7 +134,7 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, struct integrity_iint_cache *iint) { struct evm_ima_xattr_data *xattr_data = NULL; - struct evm_ima_xattr_data calc; + struct evm_xattr calc; enum integrity_status evm_status = INTEGRITY_PASS; struct inode *inode; int rc, xattr_len; @@ -167,7 +167,7 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, /* check value type */ switch (xattr_data->type) { case EVM_XATTR_HMAC: - if (xattr_len != sizeof(struct evm_ima_xattr_data)) { + if (xattr_len != sizeof(struct evm_xattr)) { evm_status = INTEGRITY_FAIL; goto out; } @@ -175,7 +175,7 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, xattr_value_len, calc.digest); if (rc) break; - rc = crypto_memneq(xattr_data->digest, calc.digest, + rc = crypto_memneq(xattr_data->data, calc.digest, sizeof(calc.digest)); if (rc) rc = -EINVAL; @@ -518,7 +518,7 @@ int evm_inode_init_security(struct inode *inode, const struct xattr *lsm_xattr, struct xattr *evm_xattr) { - struct evm_ima_xattr_data *xattr_data; + struct evm_xattr *xattr_data; int rc; if (!evm_key_loaded() || !evm_protected_xattr(lsm_xattr->name)) @@ -528,7 +528,7 @@ int evm_inode_init_security(struct inode *inode, if (!xattr_data) return -ENOMEM; - xattr_data->type = EVM_XATTR_HMAC; + xattr_data->data.type = EVM_XATTR_HMAC; rc = evm_init_hmac(inode, lsm_xattr, xattr_data->digest); if (rc < 0) goto out; diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 8bd7a0733e51..a6b2995b7d0b 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -167,7 +167,8 @@ enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, return sig->hash_algo; break; case IMA_XATTR_DIGEST_NG: - ret = xattr_value->digest[0]; + /* first byte contains algorithm id */ + ret = xattr_value->data[0]; if (ret < HASH_ALGO__LAST) return ret; break; @@ -175,7 +176,7 @@ enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, /* this is for backward compatibility */ if (xattr_len == 21) { unsigned int zero = 0; - if (!memcmp(&xattr_value->digest[16], &zero, 4)) + if (!memcmp(&xattr_value->data[16], &zero, 4)) return HASH_ALGO_MD5; else return HASH_ALGO_SHA1; @@ -274,7 +275,7 @@ int ima_appraise_measurement(enum ima_hooks func, /* xattr length may be longer. md5 hash in previous version occupied 20 bytes in xattr, instead of 16 */ - rc = memcmp(&xattr_value->digest[hash_start], + rc = memcmp(&xattr_value->data[hash_start], iint->ima_hash->digest, iint->ima_hash->length); else diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 0bb372eed62a..714fe2e135c7 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -78,6 +78,11 @@ enum evm_ima_xattr_type { struct evm_ima_xattr_data { u8 type; + u8 data[]; +} __packed; + +struct evm_xattr { + struct evm_ima_xattr_data data; u8 digest[SHA1_DIGEST_SIZE]; } __packed;