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,URIBL_BLOCKED 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 41BF6C43441 for ; Mon, 19 Nov 2018 10:13:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EB2CD206BA for ; Mon, 19 Nov 2018 10:13:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EB2CD206BA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727706AbeKSUgv (ORCPT ); Mon, 19 Nov 2018 15:36:51 -0500 Received: from terminus.zytor.com ([198.137.202.136]:34179 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726287AbeKSUgu (ORCPT ); Mon, 19 Nov 2018 15:36:50 -0500 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id wAJADVsO2523716 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 19 Nov 2018 02:13:31 -0800 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id wAJADVeR2523713; Mon, 19 Nov 2018 02:13:31 -0800 Date: Mon, 19 Nov 2018 02:13:31 -0800 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: "tip-bot for Maciej S. Szmigiero" Message-ID: Cc: mail@maciej.szmigiero.name, linux-kernel@vger.kernel.org, hpa@zytor.com, x86@kernel.org, tglx@linutronix.de, bp@suse.de, mingo@kernel.org Reply-To: tglx@linutronix.de, mingo@kernel.org, bp@suse.de, hpa@zytor.com, linux-kernel@vger.kernel.org, mail@maciej.szmigiero.name, x86@kernel.org In-Reply-To: <3014e96c82cd90761b4601bd2cfe59c4119e46a7.1529424596.git.mail@maciej.szmigiero.name> References: <3014e96c82cd90761b4601bd2cfe59c4119e46a7.1529424596.git.mail@maciej.szmigiero.name> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/microcode] x86/microcode/AMD: Add microcode container verification Git-Commit-ID: f4ff25916c1186912e1b53c25861c8abc9f15687 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: f4ff25916c1186912e1b53c25861c8abc9f15687 Gitweb: https://git.kernel.org/tip/f4ff25916c1186912e1b53c25861c8abc9f15687 Author: Maciej S. Szmigiero AuthorDate: Tue, 19 Jun 2018 20:47:32 +0200 Committer: Borislav Petkov CommitDate: Mon, 19 Nov 2018 10:45:03 +0100 x86/microcode/AMD: Add microcode container verification Add container and patch verification functions to the AMD microcode update driver. These functions check whether a passed buffer contains the relevant structure, whether it isn't truncated and (for actual microcode patches) whether the size of a patch is not too large for a particular CPU family. By adding these checks as separate functions the actual microcode loading code won't get interspersed with a lot of checks and so will be more readable. [ bp: Make all pr_err() calls into pr_debug() and drop the verify_patch() bits. ] Signed-off-by: Maciej S. Szmigiero Signed-off-by: Borislav Petkov Cc: x86-ml Link: http://lkml.kernel.org/r/3014e96c82cd90761b4601bd2cfe59c4119e46a7.1529424596.git.mail@maciej.szmigiero.name --- arch/x86/kernel/cpu/microcode/amd.c | 101 ++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index b44c9029860c..36aeb01b3ae8 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -73,6 +73,107 @@ static u16 find_equiv_id(struct equiv_cpu_entry *equiv_table, u32 sig) return 0; } +/* + * Check whether there is a valid microcode container file at the beginning + * of @buf of size @buf_size. Set @early to use this function in the early path. + */ +static bool verify_container(const u8 *buf, size_t buf_size, bool early) +{ + u32 cont_magic; + + if (buf_size <= CONTAINER_HDR_SZ) { + if (!early) + pr_debug("Truncated microcode container header.\n"); + + return false; + } + + cont_magic = *(const u32 *)buf; + if (cont_magic != UCODE_MAGIC) { + if (!early) + pr_debug("Invalid magic value (0x%08x).\n", cont_magic); + + return false; + } + + return true; +} + +/* + * Check whether there is a valid, non-truncated CPU equivalence table at the + * beginning of @buf of size @buf_size. Set @early to use this function in the + * early path. + */ +static bool verify_equivalence_table(const u8 *buf, size_t buf_size, bool early) +{ + const u32 *hdr = (const u32 *)buf; + u32 cont_type, equiv_tbl_len; + + if (!verify_container(buf, buf_size, early)) + return false; + + cont_type = hdr[1]; + if (cont_type != UCODE_EQUIV_CPU_TABLE_TYPE) { + if (!early) + pr_debug("Wrong microcode container equivalence table type: %u.\n", + cont_type); + + return false; + } + + buf_size -= CONTAINER_HDR_SZ; + + equiv_tbl_len = hdr[2]; + if (equiv_tbl_len < sizeof(struct equiv_cpu_entry) || + buf_size < equiv_tbl_len) { + if (!early) + pr_debug("Truncated equivalence table.\n"); + + return false; + } + + return true; +} + +/* + * Check whether there is a valid, non-truncated microcode patch section at the + * beginning of @buf of size @buf_size. Set @early to use this function in the + * early path. + */ +static bool verify_patch_section(const u8 *buf, size_t buf_size, bool early) +{ + const u32 *hdr; + u32 patch_type, patch_size; + + if (buf_size < SECTION_HDR_SIZE) { + if (!early) + pr_debug("Truncated patch section.\n"); + + return false; + } + + hdr = (const u32 *)buf; + patch_type = hdr[0]; + patch_size = hdr[1]; + + if (patch_type != UCODE_UCODE_TYPE) { + if (!early) + pr_debug("Invalid type field (0x%x) in container file section header.\n", + patch_type); + + return false; + } + + if (patch_size < sizeof(struct microcode_header_amd)) { + if (!early) + pr_debug("Patch of size %u too short.\n", patch_size); + + return false; + } + + return true; +} + /* * This scans the ucode blob for the proper container as we can have multiple * containers glued together. Returns the equivalence ID from the equivalence