From patchwork Tue Jun 11 06:28:08 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: 10986049 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 38C7E13AD for ; Tue, 11 Jun 2019 06:29:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2987D285C8 for ; Tue, 11 Jun 2019 06:29:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1DAF328712; Tue, 11 Jun 2019 06:29:42 +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 9D53B285C8 for ; Tue, 11 Jun 2019 06:29:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404051AbfFKG3f (ORCPT ); Tue, 11 Jun 2019 02:29:35 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:52192 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404044AbfFKG3f (ORCPT ); Tue, 11 Jun 2019 02:29:35 -0400 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5B6RPeq104215 for ; Tue, 11 Jun 2019 02:29:34 -0400 Received: from e34.co.us.ibm.com (e34.co.us.ibm.com [32.97.110.152]) by mx0a-001b2d01.pphosted.com with ESMTP id 2t25efbhn8-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 11 Jun 2019 02:29:34 -0400 Received: from localhost by e34.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, 11 Jun 2019 07:29:26 +0100 Received: from b03ledav006.gho.boulder.ibm.com (b03ledav006.gho.boulder.ibm.com [9.17.130.237]) by b03cxnp08027.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x5B6TP8a23134580 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 11 Jun 2019 06:29:25 GMT Received: from b03ledav006.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4FD2DC605D; Tue, 11 Jun 2019 06:29:25 +0000 (GMT) Received: from b03ledav006.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AC7C0C605A; Tue, 11 Jun 2019 06:29:20 +0000 (GMT) Received: from morokweng.localdomain.com (unknown [9.85.227.34]) by b03ledav006.gho.boulder.ibm.com (Postfix) with ESMTP; Tue, 11 Jun 2019 06:29:20 +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 v11 04/13] integrity: Introduce struct evm_xattr Date: Tue, 11 Jun 2019 03:28:08 -0300 X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190611062817.18412-1-bauerman@linux.ibm.com> References: <20190611062817.18412-1-bauerman@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19061106-0016-0000-0000-000009C11C5A X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011245; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000286; SDB=6.01216304; UDB=6.00639510; IPR=6.00997403; MB=3.00027259; MTD=3.00000008; XFM=3.00000015; UTC=2019-06-11 06:29:31 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19061106-0017-0000-0000-0000439AFD08 Message-Id: <20190611062817.18412-5-bauerman@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-11_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-1906110044 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 2f6536ab69e8..18bbe753421a 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;