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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 B3F4BC04EB9 for ; Mon, 3 Dec 2018 13:07:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8359320878 for ; Mon, 3 Dec 2018 13:07:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8359320878 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-integrity-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725957AbeLCNIA (ORCPT ); Mon, 3 Dec 2018 08:08:00 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54886 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725830AbeLCNIA (ORCPT ); Mon, 3 Dec 2018 08:08:00 -0500 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wB3D6uVG098949 for ; Mon, 3 Dec 2018 08:07:01 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2p54vy0m61-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 03 Dec 2018 08:06:56 -0500 Received: from localhost by e06smtp05.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) Mon, 3 Dec 2018 13:04:08 -0000 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wB3D47GQ55181496 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 3 Dec 2018 13:04:07 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1912342049; Mon, 3 Dec 2018 13:04:07 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 70E3642042; Mon, 3 Dec 2018 13:04:06 +0000 (GMT) Received: from localhost.localdomain (unknown [9.80.106.63]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 3 Dec 2018 13:04:06 +0000 (GMT) Subject: Re: [PATCH v3 1/7] ima-evm-utils: Fix hash buffer overflow in verify_evm and hmac_evm From: Mimi Zohar To: Vitaly Chikunov , Mimi Zohar , Dmitry Kasatkin , linux-integrity@vger.kernel.org Date: Mon, 03 Dec 2018 08:03:55 -0500 In-Reply-To: <20181203033525.20431-1-vt@altlinux.org> References: <20181203033525.20431-1-vt@altlinux.org> 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: 18120313-0020-0000-0000-000002F15B1C X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18120313-0021-0000-0000-00002140CCED Message-Id: <1543842235.4216.221.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-12-03_07:,, 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-1812030124 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Mon, 2018-12-03 at 06:35 +0300, Vitaly Chikunov wrote: > Commit ae1319eeabd6 ("Remove hardcoding of SHA1 in EVM signatures") > introduces overflow of 20 byte buffer on the stack while calculating > hash. Also, invalid hash length is passed to the underlying verification > function in verify_evm. This prevents any non-SHA1 hashes from being > properly validated using evmctl. > > Fixes: ae1319eeabd6 ("Remove hardcoding of SHA1 in EVM signatures") > Signed-off-by: Vitaly Chikunov Thank you!  This patch set has now been applied and is in master. Mimi > --- > Changes since v1: > - Fix similar issue in hmac_evm > Changes since v2: > - No changes. > > src/evmctl.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/src/evmctl.c b/src/evmctl.c > index 1b46d58..f8035da 100644 > --- a/src/evmctl.c > +++ b/src/evmctl.c > @@ -55,6 +55,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -760,13 +761,15 @@ static int cmd_sign_evm(struct command *cmd) > > static int verify_evm(const char *file) > { > - unsigned char hash[20]; > + unsigned char hash[64]; > unsigned char sig[1024]; > + int mdlen; > int len; > > - len = calc_evm_hash(file, hash); > - if (len <= 1) > - return len; > + mdlen = calc_evm_hash(file, hash); > + assert(mdlen <= sizeof(hash)); > + if (mdlen <= 1) > + return mdlen; > > len = lgetxattr(file, "security.evm", sig, sizeof(sig)); > if (len < 0) { > @@ -779,7 +782,7 @@ static int verify_evm(const char *file) > return -1; > } > > - return verify_hash(file, hash, sizeof(hash), sig + 1, len - 1); > + return verify_hash(file, hash, mdlen, sig + 1, len - 1); > } > > static int cmd_verify_evm(struct command *cmd) > @@ -1135,11 +1138,12 @@ out: > > static int hmac_evm(const char *file, const char *key) > { > - unsigned char hash[20]; > + unsigned char hash[64]; > unsigned char sig[1024]; > int len, err; > > len = calc_evm_hmac(file, key, hash); > + assert(len <= sizeof(hash)); > if (len <= 1) > return len; >