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=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,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 4D69AC282C2 for ; Wed, 13 Feb 2019 09:07:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 25163222BB for ; Wed, 13 Feb 2019 09:07:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391220AbfBMJHn (ORCPT ); Wed, 13 Feb 2019 04:07:43 -0500 Received: from terminus.zytor.com ([198.137.202.136]:50109 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727954AbfBMJHn (ORCPT ); Wed, 13 Feb 2019 04:07:43 -0500 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x1D96tEA199087 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 13 Feb 2019 01:06:55 -0800 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x1D96tK7199084; Wed, 13 Feb 2019 01:06:55 -0800 Date: Wed, 13 Feb 2019 01:06:55 -0800 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Borislav Petkov Message-ID: Cc: keescook@chromium.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, x86@kernel.org, linux@roeck-us.net, bp@suse.de, hpa@zytor.com, fanc.fnst@cn.fujitsu.com, mingo@kernel.org, ard.biesheuvel@linaro.org, mingo@redhat.com Reply-To: linux-kernel@vger.kernel.org, keescook@chromium.org, x86@kernel.org, tglx@linutronix.de, linux@roeck-us.net, bp@suse.de, hpa@zytor.com, fanc.fnst@cn.fujitsu.com, mingo@kernel.org, ard.biesheuvel@linaro.org, mingo@redhat.com In-Reply-To: <20190208190248.GA10854@roeck-us.net> References: <20190208190248.GA10854@roeck-us.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/boot] x86/boot: Correct RSDP parsing with 32-bit EFI Git-Commit-ID: 022442cbec93433ac260a417ab89a960ae6058f8 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 022442cbec93433ac260a417ab89a960ae6058f8 Gitweb: https://git.kernel.org/tip/022442cbec93433ac260a417ab89a960ae6058f8 Author: Borislav Petkov AuthorDate: Mon, 11 Feb 2019 12:19:45 +0100 Committer: Borislav Petkov CommitDate: Wed, 13 Feb 2019 09:59:35 +0100 x86/boot: Correct RSDP parsing with 32-bit EFI Guenter Roeck reported triple faults of a 64-bit VM using a 32-bit OVMF EFI image. After some singlestepping of the image in gdb, it turned out that some of the EFI config tables were at bogus addresses. Which, as Ard pointed out, results from using the wrong efi_config_table typedef. So switch all EFI table pointers to unsigned longs and convert them to the proper typedef only when accessing them. This way, the proper table type is being used. Shorten variable names, while at it. Fixes: 33f0df8d843d ("x86/boot: Search for RSDP in the EFI tables") Reported-by: Guenter Roeck Signed-off-by: Borislav Petkov Tested-by: Chao Fan Cc: Ard Biesheuvel Cc: bhe@redhat.com Cc: caoj.fnst@cn.fujitsu.com Cc: "H. Peter Anvin" Cc: indou.takao@jp.fujitsu.com Cc: Ingo Molnar Cc: kasong@redhat.com Cc: Kees Cook Cc: msys.mizuma@gmail.com Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20190208190248.GA10854@roeck-us.net --- arch/x86/boot/compressed/acpi.c | 50 +++++++++++++++++++++++++---------------- 1 file changed, 31 insertions(+), 19 deletions(-) diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c index c5a949335d8b..f8a321e30cc0 100644 --- a/arch/x86/boot/compressed/acpi.c +++ b/arch/x86/boot/compressed/acpi.c @@ -50,7 +50,8 @@ static acpi_physical_address efi_get_rsdp_addr(void) acpi_physical_address rsdp_addr = 0; #ifdef CONFIG_EFI - efi_system_table_t *systab; + unsigned long systab, systab_tables, config_tables; + unsigned int nr_tables; struct efi_info *ei; bool efi_64; int size, i; @@ -70,46 +71,57 @@ static acpi_physical_address efi_get_rsdp_addr(void) /* Get systab from boot params. */ #ifdef CONFIG_X86_64 - systab = (efi_system_table_t *)(ei->efi_systab | ((__u64)ei->efi_systab_hi<<32)); + systab = ei->efi_systab | ((__u64)ei->efi_systab_hi << 32); #else if (ei->efi_systab_hi || ei->efi_memmap_hi) { debug_putstr("Error getting RSDP address: EFI system table located above 4GB.\n"); return 0; } - systab = (efi_system_table_t *)ei->efi_systab; + systab = ei->efi_systab; #endif if (!systab) error("EFI system table not found."); - /* - * Get EFI tables from systab. - */ - size = efi_64 ? sizeof(efi_config_table_64_t) : - sizeof(efi_config_table_32_t); + /* Handle EFI bitness properly */ + if (efi_64) { + efi_system_table_64_t *stbl = (efi_system_table_64_t *)systab; + + config_tables = stbl->tables; + nr_tables = stbl->nr_tables; + size = sizeof(efi_config_table_64_t); + } else { + efi_system_table_32_t *stbl = (efi_system_table_32_t *)systab; - for (i = 0; i < systab->nr_tables; i++) { + config_tables = stbl->tables; + nr_tables = stbl->nr_tables; + size = sizeof(efi_config_table_32_t); + } + + if (!config_tables) + error("EFI config tables not found."); + + /* Get EFI tables from systab. */ + for (i = 0; i < nr_tables; i++) { acpi_physical_address table; - void *config_tables; efi_guid_t guid; - config_tables = (void *)(systab->tables + size * i); + config_tables += size * i; + if (efi_64) { - efi_config_table_64_t *tmp_table; + efi_config_table_64_t *tbl = (efi_config_table_64_t *)config_tables; - tmp_table = config_tables; - guid = tmp_table->guid; - table = tmp_table->table; + guid = tbl->guid; + table = tbl->table; if (!IS_ENABLED(CONFIG_X86_64) && table >> 32) { debug_putstr("Error getting RSDP address: EFI config table located above 4GB.\n"); return 0; } } else { - efi_config_table_32_t *tmp_table; + efi_config_table_32_t *tbl = (efi_config_table_32_t *)config_tables; - tmp_table = config_tables; - guid = tmp_table->guid; - table = tmp_table->table; + guid = tbl->guid; + table = tbl->table; } if (!(efi_guidcmp(guid, ACPI_TABLE_GUID)))