From patchwork Thu Apr 18 03:51:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thiago Jung Bauermann X-Patchwork-Id: 10906487 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D843D17E0 for ; Thu, 18 Apr 2019 03:52:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C37B528BEA for ; Thu, 18 Apr 2019 03:52:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B77B028BE1; Thu, 18 Apr 2019 03:52:24 +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=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 9AD1728BE1 for ; Thu, 18 Apr 2019 03:52:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388045AbfDRDwL (ORCPT ); Wed, 17 Apr 2019 23:52:11 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:44122 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388023AbfDRDwK (ORCPT ); Wed, 17 Apr 2019 23:52:10 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x3I3o7JU089636 for ; Wed, 17 Apr 2019 23:52:09 -0400 Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) by mx0a-001b2d01.pphosted.com with ESMTP id 2rxegqx4vv-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 17 Apr 2019 23:52:09 -0400 Received: from localhost by e33.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) Thu, 18 Apr 2019 04:52:03 +0100 Received: from b03ledav004.gho.boulder.ibm.com (b03ledav004.gho.boulder.ibm.com [9.17.130.235]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x3I3q11B20643844 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 18 Apr 2019 03:52:01 GMT Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 912857805F; Thu, 18 Apr 2019 03:52:01 +0000 (GMT) Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6CEB178060; Thu, 18 Apr 2019 03:51:57 +0000 (GMT) Received: from morokweng.localdomain.com (unknown [9.85.230.182]) by b03ledav004.gho.boulder.ibm.com (Postfix) with ESMTP; Thu, 18 Apr 2019 03:51:57 +0000 (GMT) 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-doc@vger.kernel.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" , Jonathan Corbet , "AKASHI, Takahiro" , Thiago Jung Bauermann Subject: [PATCH v10 04/12] integrity: Introduce struct evm_xattr Date: Thu, 18 Apr 2019 00:51:12 -0300 X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190418035120.2354-1-bauerman@linux.ibm.com> References: <20190418035120.2354-1-bauerman@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19041803-0036-0000-0000-00000AAA1A16 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010947; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000284; SDB=6.01190666; UDB=6.00623948; IPR=6.00971462; MB=3.00026492; MTD=3.00000008; XFM=3.00000015; UTC=2019-04-18 03:52:07 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19041803-0037-0000-0000-00004B6E444B Message-Id: <20190418035120.2354-5-bauerman@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-04-18_03:,, 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 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904180023 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: 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, specifically the EVM HMAC code. Signed-off-by: Thiago Jung Bauermann Reviewed-by: Mimi Zohar --- security/integrity/evm/evm_main.c | 8 ++++---- security/integrity/ima/ima_appraise.c | 7 ++++--- security/integrity/integrity.h | 6 ++++++ 3 files changed, 14 insertions(+), 7 deletions(-) diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index b6d9f14bc234..588f22f1b5bd 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -169,7 +169,7 @@ 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; } @@ -179,7 +179,7 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry, xattr_value_len, &digest); if (rc) break; - rc = crypto_memneq(xattr_data->digest, digest.digest, + rc = crypto_memneq(xattr_data->data, digest.digest, SHA1_DIGEST_SIZE); if (rc) rc = -EINVAL; @@ -523,7 +523,7 @@ 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)) @@ -533,7 +533,7 @@ 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 5fb7127bbe68..ea8fa29f07d3 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -168,7 +168,8 @@ 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; @@ -176,7 +177,7 @@ 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; @@ -275,7 +276,7 @@ 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 7de59f44cba3..88a29f72a74f 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -79,6 +79,12 @@ enum evm_ima_xattr_type { struct evm_ima_xattr_data { u8 type; + u8 data[]; +} __packed; + +/* Only used in the EVM HMAC code. */ +struct evm_xattr { + struct evm_ima_xattr_data data; u8 digest[SHA1_DIGEST_SIZE]; } __packed;