From patchwork Thu Apr 8 13:15:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris von Recklinghausen X-Patchwork-Id: 418319 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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, 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 1811CC433ED for ; Thu, 8 Apr 2021 13:15:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED2AC6113A for ; Thu, 8 Apr 2021 13:15:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231370AbhDHNPa (ORCPT ); Thu, 8 Apr 2021 09:15:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:43578 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231221AbhDHNPa (ORCPT ); Thu, 8 Apr 2021 09:15:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617887718; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc; bh=gLt21bPJvIlBR5BbmtTsJshwg3KlcFfFwYxjyRKrbvM=; b=DHB31UkfzQ3uLiOE21aM8+52bPuwCoP3ojxO+ZUWQ+758aFJ5GaeM1vSEpi5yq/nfSV5H0 Wzb1I1fbjVU0UK8YFCPcxyoMI5retzXuBT1flOnVUnZtPEAkHnHpMaBNsPtuRJm57P1VWw 6pDlnsc1Rz37AHyxtliQifwb4b3MWGY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-320-PBkQ729jOAWSq-NZqXgMKw-1; Thu, 08 Apr 2021 09:15:16 -0400 X-MC-Unique: PBkQ729jOAWSq-NZqXgMKw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0267F81744F; Thu, 8 Apr 2021 13:15:14 +0000 (UTC) Received: from crecklin.bos.com (ovpn-113-158.rdu2.redhat.com [10.10.113.158]) by smtp.corp.redhat.com (Postfix) with ESMTP id CA82960C5F; Thu, 8 Apr 2021 13:15:07 +0000 (UTC) From: Chris von Recklinghausen To: ardb@kernel.org, simo@redhat.com, rafael@kernel.org, decui@microsoft.com, linux-pm@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 1/1] use crc32 instead of md5 for hibernation e820 integrity check Date: Thu, 8 Apr 2021 09:15:06 -0400 Message-Id: <20210408131506.17941-1-crecklin@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Suspend fails on a system in fips mode because md5 is used for the e820 integrity check and is not available. Use crc32 instead. This patch changes the integrity check algorithm from md5 to crc32. This integrity check is used only to verify accidental corruption of the hybernation data and is not intended as a cryptographic integrity check. Md5 is overkill in this case and also disabled in FIPS mode because it is known to be broken for cryptographic purposes. Fixes: 62a03defeabd ("PM / hibernate: Verify the consistent of e820 memory map by md5 digest") Tested-by: Dexuan Cui Reviewed-by: Dexuan Cui Signed-off-by: Chris von Recklinghausen --- v1 -> v2 bump up RESTORE_MAGIC v2 -> v3 move embelishment from cover letter to commit comments (no code change) v3 -> v4 add note to comments that md5 isn't used for encryption here. v4 -> v5 reword comment per Simo's suggestion arch/x86/power/hibernate.c | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) diff --git a/arch/x86/power/hibernate.c b/arch/x86/power/hibernate.c index cd3914fc9f3d..b56172553275 100644 --- a/arch/x86/power/hibernate.c +++ b/arch/x86/power/hibernate.c @@ -55,31 +55,31 @@ int pfn_is_nosave(unsigned long pfn) } -#define MD5_DIGEST_SIZE 16 +#define CRC32_DIGEST_SIZE 16 struct restore_data_record { unsigned long jump_address; unsigned long jump_address_phys; unsigned long cr3; unsigned long magic; - u8 e820_digest[MD5_DIGEST_SIZE]; + u8 e820_digest[CRC32_DIGEST_SIZE]; }; -#if IS_BUILTIN(CONFIG_CRYPTO_MD5) +#if IS_BUILTIN(CONFIG_CRYPTO_CRC32) /** - * get_e820_md5 - calculate md5 according to given e820 table + * get_e820_crc32 - calculate crc32 according to given e820 table * * @table: the e820 table to be calculated - * @buf: the md5 result to be stored to + * @buf: the crc32 result to be stored to */ -static int get_e820_md5(struct e820_table *table, void *buf) +static int get_e820_crc32(struct e820_table *table, void *buf) { struct crypto_shash *tfm; struct shash_desc *desc; int size; int ret = 0; - tfm = crypto_alloc_shash("md5", 0, 0); + tfm = crypto_alloc_shash("crc32", 0, 0); if (IS_ERR(tfm)) return -ENOMEM; @@ -107,24 +107,24 @@ static int get_e820_md5(struct e820_table *table, void *buf) static int hibernation_e820_save(void *buf) { - return get_e820_md5(e820_table_firmware, buf); + return get_e820_crc32(e820_table_firmware, buf); } static bool hibernation_e820_mismatch(void *buf) { int ret; - u8 result[MD5_DIGEST_SIZE]; + u8 result[CRC32_DIGEST_SIZE]; - memset(result, 0, MD5_DIGEST_SIZE); + memset(result, 0, CRC32_DIGEST_SIZE); /* If there is no digest in suspend kernel, let it go. */ - if (!memcmp(result, buf, MD5_DIGEST_SIZE)) + if (!memcmp(result, buf, CRC32_DIGEST_SIZE)) return false; - ret = get_e820_md5(e820_table_firmware, result); + ret = get_e820_crc32(e820_table_firmware, result); if (ret) return true; - return memcmp(result, buf, MD5_DIGEST_SIZE) ? true : false; + return memcmp(result, buf, CRC32_DIGEST_SIZE) ? true : false; } #else static int hibernation_e820_save(void *buf) @@ -134,15 +134,15 @@ static int hibernation_e820_save(void *buf) static bool hibernation_e820_mismatch(void *buf) { - /* If md5 is not builtin for restore kernel, let it go. */ + /* If crc32 is not builtin for restore kernel, let it go. */ return false; } #endif #ifdef CONFIG_X86_64 -#define RESTORE_MAGIC 0x23456789ABCDEF01UL +#define RESTORE_MAGIC 0x23456789ABCDEF02UL #else -#define RESTORE_MAGIC 0x12345678UL +#define RESTORE_MAGIC 0x12345679UL #endif /** @@ -160,6 +160,9 @@ int arch_hibernation_header_save(void *addr, unsigned int max_size) rdr->jump_address = (unsigned long)restore_registers; rdr->jump_address_phys = __pa_symbol(restore_registers); + /* crc32 digest size is 4 but digest buffer size is 16 so zero it all */ + memset(rdr->e820_digest, 0, CRC32_DIGEST_SIZE); + /* * The restore code fixes up CR3 and CR4 in the following sequence: *