From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-763432-1523533108-2-10433219823854076287 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no ("Email failed DMARC policy for domain") X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, MAILING_LIST_MULTI -1, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-IgnoreVacation: yes ("Email failed DMARC policy for domain") X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: linux-api-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1523533107; b=FNGtCBpEWE7yDoJWuxCCDJtdDouB+QWOdmjNqrL9UY056xyGbg 2B339rymzfWSHfT8OifQ9slNywGAhsbQ9UU9qBB9qPsi3BSQciHU8IaSvVgO0Okc KPtD2ECnVtzaMInAfY7PL0A6zeHpwMTaSLBU0/c3OINQBp7/FP7h6gsucj0XLKKw kgIEhYy7UkRbYZHp0Jtb+S0VKb9bEYIlc1qXlF4iU0N0ugw/T5LsOiBAEojjccBs Ce7DIdlBIzz943uOUcMuPkWYUAE08LyfyG1/kj1tkPjzp3bXBxhUuv5ur3O2lqzU ZzdmmR6oXXQgvYx0Pxd+nJzASdEGlNdW8uNQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=subject:from:to:cc:date:in-reply-to :references:content-type:mime-version:content-transfer-encoding :message-id:sender:list-id; s=fm2; t=1523533107; bh=X5SOgozDKtO7 j5qFnRTaXWqn6FQBmLwdbAhbQQ3kzMY=; b=aZAu4O/J7hWtD4NeGrXnxMiRwnXA pYMA12x8g2lc1ruOIRZ3JEJ3cr0ZHWT28xg7LD3S/tC1QSCSjeu0i3bxYX3rzGaF T3ASck7qkoBsHWrD0R/70EgPhYtfBzu3Hk7AnA9BEN57rXyce2Yiw7Syf5QeOiXS iunNPM6jQagWnikBptkWoAPTh+6cvJaAQNk3gWP8OtrzsfP+wkapog3Lm3p+pNBd mDlyt/IjOaB12kUFpD4vFRrMk93WnGrWDo37yxhlkZaEicjCVVO28l8F94JOhXBY CVGM91wYGjAiPfswRwwCNX1S7nU+xH/rG7P0/89znkJRaM+CyT83O+ZhvQ== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=fail (p=none,has-list-id=yes,d=none) header.from=linux.vnet.ibm.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linux.vnet.ibm.com header.result=pass header_org.domain=ibm.com header_org.result=pass header_is_org_domain=no; x-vs=clean score=-100 state=0 Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=fail (p=none,has-list-id=yes,d=none) header.from=linux.vnet.ibm.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linux.vnet.ibm.com header.result=pass header_org.domain=ibm.com header_org.result=pass header_is_org_domain=no; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfJ/RBGmPk40ODewxLJMLdm3sgvt4U1njIMsWWPuSqDnF8ze4TL0d9r0rV9yk6m3giaH5xycyh7smA91oBtup+3rHo8CX/KkoTrmh7MVywJwR5jztOR6P 38FYY+YoJmtZq3RVuWBXLMYahxpj3bgE4jlAy9DILzwpJY30/pP6yKf9ZPjZQeUy6HN+KddTw+JLAugvNMwXkOtMZG3zHpVQNVFMPANVQsORlAvOUNwKo7jw X-CM-Analysis: v=2.3 cv=WaUilXpX c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=IkcTkHD0fZMA:10 a=Kd1tUaAdevIA:10 a=20KFwNOVAAAA:8 a=9Rt4o3Z7AAAA:8 a=PtDNVHqPAAAA:8 a=VwQbUJbxAAAA:8 a=pwH9GBqdFiE-RNno6p0A:9 a=QEXdDO2ut3YA:10 a=kXfSGICM7I4A:10 a=x8gzFH9gYPwA:10 a=jE01AiZSAJ7eki2zvjzZ:22 a=BpimnaHY1jUKGyF_4-AF:22 a=AjGcO6oz07-iQ99wixmX:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751863AbeDLLiZ (ORCPT ); Thu, 12 Apr 2018 07:38:25 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:38508 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750763AbeDLLiZ (ORCPT ); Thu, 12 Apr 2018 07:38:25 -0400 Subject: Re: [PATCH 06/24] kexec_load: Disable at runtime if the kernel is locked down From: Mimi Zohar To: "Eric W. Biederman" , David Howells Cc: torvalds@linux-foundation.org, linux-man@vger.kernel.org, linux-api@vger.kernel.org, jmorris@namei.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Date: Thu, 12 Apr 2018 07:38:17 -0400 In-Reply-To: <1523477375.5268.78.camel@linux.vnet.ibm.com> References: <152346387861.4030.4408662483445703127.stgit@warthog.procyon.org.uk> <152346391877.4030.6270466586590461223.stgit@warthog.procyon.org.uk> <87po35k1q6.fsf@xmission.com> <1523477375.5268.78.camel@linux.vnet.ibm.com> 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: 18041211-0040-0000-0000-0000042D7CFB X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18041211-0041-0000-0000-00002631958B Message-Id: <1523533097.31852.11.camel@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-04-12_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 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1804120119 Sender: linux-api-owner@vger.kernel.org X-Mailing-List: linux-api@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Wed, 2018-04-11 at 16:09 -0400, Mimi Zohar wrote: > On Wed, 2018-04-11 at 14:00 -0500, Eric W. Biederman wrote: > > David Howells writes: > > > > > From: Matthew Garrett > > > > > > The kexec_load() syscall permits the loading and execution of arbitrary > > > code in ring 0, which is something that lock-down is meant to prevent. It > > > makes sense to disable kexec_load() in this situation. > > > > > > This does not affect kexec_file_load() syscall which can check for a > > > signature on the image to be booted. > > > > Maybing I am missing it but I am not seeing anything that would require > > kexec_file_load be configured such that it checks the loaded kernel. > > > > Without that I don't see the point of disabling kexec_load. > > > > Nacked-by: "Eric W. Biederman" > > The IMA "secure boot" policy requires the kexec image to be signed. >  This call to kernel_is_locked_down() could be replaced with a call > to security_kernel_read_file(NULL, READING_KEXEC_IMAGE). > > It would be similar to the existing init_module syscall calling > security_kernel_read_file(). David, enabling the IMA-appraisal "secure boot" policy should probably not be dependent on lockdown either. Mimi