Received: by 2002:ad5:4acb:0:0:0:0:0 with SMTP id n11csp3972865imw; Thu, 7 Jul 2022 10:27:20 -0700 (PDT) X-Google-Smtp-Source: AGRyM1suPsR26ItFojwziV2YzQ2xrdpZ7G9QzAt/3HmwEIEXawsLKZ8eOnv1hdCjO91FcyoNotZv X-Received: by 2002:a17:907:1c08:b0:72a:8a2d:db4a with SMTP id nc8-20020a1709071c0800b0072a8a2ddb4amr35070571ejc.89.1657214839764; Thu, 07 Jul 2022 10:27:19 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1657214839; cv=none; d=google.com; s=arc-20160816; b=XzBJgchxPanIbOUFsNOd4mUWE4A3Qv4nsh7a91pDJjor70s+3xXTvpF4A5MDcyeJQZ pjrwU2L2rqhCTRBgdaUeBZ0vME9cCm1cnS5aHclHFK6wTKkCtKXBz7sH2+Gd8ZtaFPAi DHpcp+jPUeuATU3y6MJCS/CW31Qsq4cSi28WJ4HW8VGPkklGF8xCTJey24dN2KM2WKu5 U9dbzv14VbOMpMLFR0uuVdQG6OXUaqS9CrQaew3upqxVRvyrDld6eCTwR7vsZHIA5Swk tLCd280KnitGbZNI1x8DyDJdhpaC6EG37SjwWK3YVLBEpBL+oMbtQvfROdLRt9wgs0wd LRPg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:content-transfer-encoding :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=MksrG9shS4R9ubTDGiwGpUBYzkdN1PukPM7LKFfZp/A=; b=eJ7ylnVBSOb1VstJTZ/HhLufWO7V9T0dWTEcSbgTMCylde5KV6MCINYDX77Uf7NKgv P0dMV1RhLVjjpTuYnksoOCds1192tV+IUPwyWI4pLLqqG9f45PFomJ17qL6Xlb/dN1AE 2VHqxt5JZF6N8ZimBvQcMyjTaV9YZgqMH0SgKNpUGj7y3wKmMTRGi1CcI93tFsu6wkWT Txity+eyfeU9R9njPTMwSGdeXUCN2evr2OJ/kc2KBHXssv8O0rlk41qyKeGKWAL4PEFr u1xtR2tX0zs/9bTrkD1BL2RI6JzX0EmT6Q52yJKmnST+sFE35/EgWMUeiTOWNhfO7nae 5MFw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@ibm.com header.s=pp1 header.b="Ll/2Kxc0"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=ibm.com Return-Path: Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id tb24-20020a1709078b9800b00726d6c9c0aasi2013314ejc.279.2022.07.07.10.26.54; Thu, 07 Jul 2022 10:27:19 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@ibm.com header.s=pp1 header.b="Ll/2Kxc0"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=ibm.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236533AbiGGRVU (ORCPT + 99 others); Thu, 7 Jul 2022 13:21:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236396AbiGGRU6 (ORCPT ); Thu, 7 Jul 2022 13:20:58 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E6124505F; Thu, 7 Jul 2022 10:20:56 -0700 (PDT) Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 267GCMOb030401; Thu, 7 Jul 2022 17:20:42 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : content-transfer-encoding : mime-version; s=pp1; bh=MksrG9shS4R9ubTDGiwGpUBYzkdN1PukPM7LKFfZp/A=; b=Ll/2Kxc0E76171d9/u/V/Rp29WbjbIvOBjM874LozKi6H8mTz5uOmAs2jkQvcDfcYDIE gNCBJ2ECwPfi3TL+n+VBZa/7iYQfrbkMpsm3QjqAcwO/GH0OVPuC5s9iyQJ50qaAVbZY rXpeyai0yHL6WG+EJLjisLI+Yi3ttVvFpna2QfAl/ONhjc8BjgQ6ZMVufub1ju7R9JmD igHecb+23lXk0n7miB9VVgdo/5mMsxevqEI2lK539Ceoho0afx58QNYeTl7Fre28XFTD CunvMXM0djlAAwg8X9QGpFtWaUKCmTKzKRYn27kTM3JtwU16GI2+0epcopKuRpyjFGLM 6g== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3h62t1hy9q-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 07 Jul 2022 17:20:42 +0000 Received: from m0187473.ppops.net (m0187473.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 267GCNOq030408; Thu, 7 Jul 2022 17:20:41 GMT Received: from ppma02wdc.us.ibm.com (aa.5b.37a9.ip4.static.sl-reverse.com [169.55.91.170]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3h62t1hy91-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 07 Jul 2022 17:20:41 +0000 Received: from pps.filterd (ppma02wdc.us.ibm.com [127.0.0.1]) by ppma02wdc.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 267H59Go024641; Thu, 7 Jul 2022 17:20:40 GMT Received: from b03cxnp07029.gho.boulder.ibm.com (b03cxnp07029.gho.boulder.ibm.com [9.17.130.16]) by ppma02wdc.us.ibm.com with ESMTP id 3h4ucxvudm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 07 Jul 2022 17:20:40 +0000 Received: from b03ledav004.gho.boulder.ibm.com (b03ledav004.gho.boulder.ibm.com [9.17.130.235]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 267HKcdP17498608 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 7 Jul 2022 17:20:39 GMT Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D7D6A78063; Thu, 7 Jul 2022 17:20:38 +0000 (GMT) Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0A8457805C; Thu, 7 Jul 2022 17:20:38 +0000 (GMT) Received: from sbct-3.pok.ibm.com (unknown [9.47.158.153]) by b03ledav004.gho.boulder.ibm.com (Postfix) with ESMTP; Thu, 7 Jul 2022 17:20:37 +0000 (GMT) From: Stefan Berger To: kexec@lists.infradead.org, devicetree@vger.kernel.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Cc: nayna@linux.ibm.com, nasastry@in.ibm.com, mpe@ellerman.id.au, Vaibhav Jain , Frank Rowand , Prakhar Srivastava , Lakshmi Ramasubramanian , Thiago Jung Bauermann , Rob Herring , Ritesh Harjani , Robin Murphy Subject: [PATCH v6 1/6] of: check previous kernel's ima-kexec-buffer against memory bounds Date: Thu, 7 Jul 2022 13:20:21 -0400 Message-Id: <20220707172026.831614-2-stefanb@linux.ibm.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220707172026.831614-1-stefanb@linux.ibm.com> References: <20220707172026.831614-1-stefanb@linux.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-GUID: 5vZG9iyF4xjmmM2zhidJkG-GcUx_N_RQ X-Proofpoint-ORIG-GUID: P-wv57F_NaFmOMJqKCojvmpuXH21gDrx Content-Transfer-Encoding: 8bit X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-07-07_13,2022-06-28_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 spamscore=0 impostorscore=0 mlxscore=0 mlxlogscore=999 priorityscore=1501 lowpriorityscore=0 suspectscore=0 adultscore=0 clxscore=1015 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2206140000 definitions=main-2207070068 X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_EF,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vaibhav Jain Presently ima_get_kexec_buffer() doesn't check if the previous kernel's ima-kexec-buffer lies outside the addressable memory range. This can result in a kernel panic if the new kernel is booted with 'mem=X' arg and the ima-kexec-buffer was allocated beyond that range by the previous kernel. The panic is usually of the form below: $ sudo kexec --initrd initrd vmlinux --append='mem=16G' BUG: Unable to handle kernel data access on read at 0xc000c01fff7f0000 Faulting instruction address: 0xc000000000837974 Oops: Kernel access of bad area, sig: 11 [#1] NIP [c000000000837974] ima_restore_measurement_list+0x94/0x6c0 LR [c00000000083b55c] ima_load_kexec_buffer+0xac/0x160 Call Trace: [c00000000371fa80] [c00000000083b55c] ima_load_kexec_buffer+0xac/0x160 [c00000000371fb00] [c0000000020512c4] ima_init+0x80/0x108 [c00000000371fb70] [c0000000020514dc] init_ima+0x4c/0x120 [c00000000371fbf0] [c000000000012240] do_one_initcall+0x60/0x2c0 [c00000000371fcc0] [c000000002004ad0] kernel_init_freeable+0x344/0x3ec [c00000000371fda0] [c0000000000128a4] kernel_init+0x34/0x1b0 [c00000000371fe10] [c00000000000ce64] ret_from_kernel_thread+0x5c/0x64 Instruction dump: f92100b8 f92100c0 90e10090 910100a0 4182050c 282a0017 3bc00000 40810330 7c0802a6 fb610198 7c9b2378 f80101d0 2c090001 40820614 e9240010 ---[ end trace 0000000000000000 ]--- Fix this issue by checking returned PFN range of previous kernel's ima-kexec-buffer with page_is_ram() to ensure correct memory bounds. Fixes: 467d27824920 ("powerpc: ima: get the kexec buffer passed by the previous kernel") Cc: Frank Rowand Cc: Prakhar Srivastava Cc: Lakshmi Ramasubramanian Cc: Thiago Jung Bauermann Cc: Rob Herring Cc: Ritesh Harjani Cc: Robin Murphy Signed-off-by: Vaibhav Jain Signed-off-by: Rob Herring Link: https://lore.kernel.org/r/20220531041446.3334259-1-vaibhav@linux.ibm.com --- drivers/of/kexec.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c index 8d374cc552be..91b04b04eec4 100644 --- a/drivers/of/kexec.c +++ b/drivers/of/kexec.c @@ -126,6 +126,7 @@ int ima_get_kexec_buffer(void **addr, size_t *size) { int ret, len; unsigned long tmp_addr; + unsigned long start_pfn, end_pfn; size_t tmp_size; const void *prop; @@ -140,6 +141,22 @@ int ima_get_kexec_buffer(void **addr, size_t *size) if (ret) return ret; + /* Do some sanity on the returned size for the ima-kexec buffer */ + if (!tmp_size) + return -ENOENT; + + /* + * Calculate the PFNs for the buffer and ensure + * they are with in addressable memory. + */ + start_pfn = PHYS_PFN(tmp_addr); + end_pfn = PHYS_PFN(tmp_addr + tmp_size - 1); + if (!page_is_ram(start_pfn) || !page_is_ram(end_pfn)) { + pr_warn("IMA buffer at 0x%lx, size = 0x%zx beyond memory\n", + tmp_addr, tmp_size); + return -EINVAL; + } + *addr = __va(tmp_addr); *size = tmp_size; -- 2.35.1