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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 24523C43381 for ; Mon, 18 Mar 2019 21:48:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EE2C22133D for ; Mon, 18 Mar 2019 21:48:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727089AbfCRVsm (ORCPT ); Mon, 18 Mar 2019 17:48:42 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:41104 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726973AbfCRVsm (ORCPT ); Mon, 18 Mar 2019 17:48:42 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x2ILig51037607 for ; Mon, 18 Mar 2019 17:48:41 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2rag47r9nm-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 18 Mar 2019 17:48:40 -0400 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 18 Mar 2019 21:48:37 -0000 Received: from b06cxnps3075.portsmouth.uk.ibm.com (9.149.109.195) by e06smtp02.uk.ibm.com (192.168.101.132) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 18 Mar 2019 21:48:35 -0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x2ILmasd51773576 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 18 Mar 2019 21:48:37 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C456E11C04C; Mon, 18 Mar 2019 21:48:36 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4B4C111C04A; Mon, 18 Mar 2019 21:48:36 +0000 (GMT) Received: from dhcp-9-31-103-153.watson.ibm.com (unknown [9.31.103.153]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 18 Mar 2019 21:48:36 +0000 (GMT) Subject: Re: Should mprotect(..., PROT_EXEC) be checked by IMA? From: Mimi Zohar To: Igor Zhbanov , linux-integrity@vger.kernel.org Date: Mon, 18 Mar 2019 17:48:35 -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: 19031821-0008-0000-0000-000002CEDA18 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19031821-0009-0000-0000-0000223AEA5B Message-Id: <1552945715.8658.299.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-03-18_13:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=62 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=972 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1903180151 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Mon, 2019-03-18 at 18:18 +0300, Igor Zhbanov wrote: > Hello! > > I've found that IMA checks for executable mmap()s but not for the combination > of mmap(..., PROT_READ, ...) + mprotect(..., PROT_EXEC). > > So it looks like is possible to load arbitrary executable code by rewriting > dlopen() and dlsym() functions to map all ELF segments read-only first then > making them executable with mprotect(). > > So should security_file_mprotect() be changed similarly > to security_mmap_file() to call IMA security hook? How?  security_mmap_file() is passed a file descriptor and the signature, stored as an xattr, can be verified. Mimi