From patchwork Tue May 1 13:48:23 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mimi Zohar X-Patchwork-Id: 10373943 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8B98460234 for ; Tue, 1 May 2018 13:49:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7D9992863F for ; Tue, 1 May 2018 13:49:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7C1AE28CA6; Tue, 1 May 2018 13:49:28 +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=ham 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 2154D28B3B for ; Tue, 1 May 2018 13:49:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755891AbeEANtY (ORCPT ); Tue, 1 May 2018 09:49:24 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:43248 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755729AbeEANs5 (ORCPT ); Tue, 1 May 2018 09:48:57 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w41DiWmK132449 for ; Tue, 1 May 2018 09:48:56 -0400 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0b-001b2d01.pphosted.com with ESMTP id 2hphst6d8k-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 01 May 2018 09:48:56 -0400 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 1 May 2018 14:48:49 +0100 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w41Dmnjh24838226; Tue, 1 May 2018 13:48:49 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B7FB44203F; Tue, 1 May 2018 14:40:02 +0100 (BST) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 02E9642047; Tue, 1 May 2018 14:40:01 +0100 (BST) Received: from localhost.ibm.com (unknown [9.80.105.194]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 1 May 2018 14:40:00 +0100 (BST) From: Mimi Zohar To: linux-integrity@vger.kernel.org Cc: Hans de Goede , Ard Biesheuvel , Peter Jones , Mimi Zohar , linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, David Howells , "Luis R . Rodriguez" , "Luis R . Rodriguez" , Kees Cook , "Serge E . Hallyn" , Stephen Boyd Subject: [RFC PATCH 6/6] ima: prevent loading firmware into a pre-allocated buffer Date: Tue, 1 May 2018 09:48:23 -0400 X-Mailer: git-send-email 2.7.5 In-Reply-To: <1525182503-13849-1-git-send-email-zohar@linux.vnet.ibm.com> References: <1525182503-13849-1-git-send-email-zohar@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18050113-0040-0000-0000-00000434CDA3 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18050113-0041-0000-0000-00002638E68E Message-Id: <1525182503-13849-7-git-send-email-zohar@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-05-01_07:, , 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 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1805010138 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Question: can the device access the pre-allocated buffer at any time? By allowing devices to request firmware be loaded directly into a pre-allocated buffer, will this allow the device access to the firmware before the kernel has verified the firmware signature? Is it dependent on the type of buffer allocated (eg. DMA)? For example, qcom_mdt_load() -> qcom_scm_pas_init_image() -> dma_alloc_coherent(). With an IMA policy requiring signed firmware, this patch would prevent loading firmware into a pre-allocated buffer. Signed-off-by: Mimi Zohar Cc: Luis R. Rodriguez Cc: David Howells Cc: Kees Cook Cc: Serge E. Hallyn Cc: Stephen Boyd --- security/integrity/ima/ima_main.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index eb9c273ab81d..3098131f77c4 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -454,6 +454,15 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id) return 0; } + if (read_id == READING_FIRMWARE_PREALLOC_BUFFER) { + if ((ima_appraise & IMA_APPRAISE_FIRMWARE) && + (ima_appraise & IMA_APPRAISE_ENFORCE)) { + pr_err("Prevent device from accessing firmware prior to verifying the firmware signature.\n"); + return -EACCES; + } + return 0; + } + if (read_id == READING_FIRMWARE_FALLBACK) { if ((ima_appraise & IMA_APPRAISE_FIRMWARE) && (ima_appraise & IMA_APPRAISE_ENFORCE)) {