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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=unavailable 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 E33D8C4646D for ; Wed, 3 Jul 2019 11:15:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C26DE218A5 for ; Wed, 3 Jul 2019 11:15:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726605AbfGCLPB (ORCPT ); Wed, 3 Jul 2019 07:15:01 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:22206 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726765AbfGCLO7 (ORCPT ); Wed, 3 Jul 2019 07:14:59 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x63BD0Bs141343 for ; Wed, 3 Jul 2019 07:14:57 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0b-001b2d01.pphosted.com with ESMTP id 2tgrajys0f-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 03 Jul 2019 07:14:56 -0400 Received: from localhost by e06smtp02.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) Wed, 3 Jul 2019 12:14:51 +0100 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x63BEpOK52953218 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 3 Jul 2019 11:14:51 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F3397A405C; Wed, 3 Jul 2019 11:14:50 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D3C8CA405B; Wed, 3 Jul 2019 11:14:49 +0000 (GMT) Received: from localhost.localdomain (unknown [9.80.110.77]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 3 Jul 2019 11:14:49 +0000 (GMT) Subject: Re: [PATCH] ima: Replace two seq_printf() calls by seq_puts() in ima_show_template_data_ascii() From: Mimi Zohar To: David Laight , "'Markus Elfring'" , "linux-integrity@vger.kernel.org" , "linux-security-module@vger.kernel.org" , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" Cc: LKML , "kernel-janitors@vger.kernel.org" Date: Wed, 03 Jul 2019 07:14:39 -0400 In-Reply-To: References: 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: 19070311-0008-0000-0000-000002F96C24 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19070311-0009-0000-0000-00002266B96B Message-Id: <1562152479.4774.18.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-07-03_03:,, 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=817 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907030135 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Wed, 2019-07-03 at 09:16 +0000, David Laight wrote: > > diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c > > index 9fe0ef7f91e2..05636e9b19b1 100644 > > --- a/security/integrity/ima/ima_template_lib.c > > +++ b/security/integrity/ima/ima_template_lib.c > > @@ -74,7 +74,7 @@ static void ima_show_template_data_ascii(struct seq_file *m, > > case DATA_FMT_DIGEST_WITH_ALGO: > > buf_ptr = strnchr(field_data->data, buflen, ':'); > > if (buf_ptr != field_data->data) > > - seq_printf(m, "%s", field_data->data); > > + seq_puts(m, field_data->data); > > > > /* skip ':' and '\0' */ > > buf_ptr += 2; > > That code looks highly suspect! > It uses a bounded scan then assumes a '\0' terminated string. > It then adds 2 to a potentially NULL pointer. The code here is used for displaying the IMA measurement list, that the kernel itself created.  Protecting the in kernel memory from attack is a different problem.  Refer to Igor Stoppa's write once memory pools. Mimi