From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752239AbbBST2t (ORCPT ); Thu, 19 Feb 2015 14:28:49 -0500 Received: from terminus.zytor.com ([198.137.202.10]:58148 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752913AbbBST2r (ORCPT ); Thu, 19 Feb 2015 14:28:47 -0500 Date: Thu, 19 Feb 2015 11:28:30 -0800 From: tip-bot for Quentin Casasnovas Message-ID: Cc: bp@suse.de, hpa@zytor.com, tglx@linutronix.de, fenghua.yu@intel.com, mingo@kernel.org, linux-kernel@vger.kernel.org, quentin.casasnovas@oracle.com Reply-To: fenghua.yu@intel.com, linux-kernel@vger.kernel.org, quentin.casasnovas@oracle.com, mingo@kernel.org, bp@suse.de, hpa@zytor.com, tglx@linutronix.de In-Reply-To: <1422964824-22056-3-git-send-email-quentin.casasnovas@oracle.com> References: <1422964824-22056-3-git-send-email-quentin.casasnovas@oracle.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/microcode/intel: Handle truncated microcode images more robustly Git-Commit-ID: 35a9ff4eec7a1725ac4364972fc6c156e4feedd0 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 35a9ff4eec7a1725ac4364972fc6c156e4feedd0 Gitweb: http://git.kernel.org/tip/35a9ff4eec7a1725ac4364972fc6c156e4feedd0 Author: Quentin Casasnovas AuthorDate: Tue, 3 Feb 2015 13:00:24 +0100 Committer: Borislav Petkov CommitDate: Thu, 19 Feb 2015 12:42:23 +0100 x86/microcode/intel: Handle truncated microcode images more robustly We do not check the input data bounds containing the microcode before copying a struct microcode_intel_header from it. A specially crafted microcode could cause the kernel to read invalid memory and lead to a denial-of-service. Signed-off-by: Quentin Casasnovas Cc: "H. Peter Anvin" Cc: Fenghua Yu Link: http://lkml.kernel.org/r/1422964824-22056-3-git-send-email-quentin.casasnovas@oracle.com [ Made error message differ from the next one and flipped comparison. ] Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/microcode/intel.c | 5 +++++ arch/x86/kernel/cpu/microcode/intel_early.c | 4 ++++ 2 files changed, 9 insertions(+) diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c index c6826d1..746e7fd 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -196,6 +196,11 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size, struct microcode_header_intel mc_header; unsigned int mc_size; + if (leftover < sizeof(mc_header)) { + pr_err("error! Truncated header in microcode data file\n"); + break; + } + if (get_ucode_data(&mc_header, ucode_ptr, sizeof(mc_header))) break; diff --git a/arch/x86/kernel/cpu/microcode/intel_early.c b/arch/x86/kernel/cpu/microcode/intel_early.c index 5e109a3..420eb93 100644 --- a/arch/x86/kernel/cpu/microcode/intel_early.c +++ b/arch/x86/kernel/cpu/microcode/intel_early.c @@ -322,6 +322,10 @@ get_matching_model_microcode(int cpu, unsigned long start, int i; while (leftover && mc_saved_count < ARRAY_SIZE(mc_saved_tmp)) { + + if (leftover < sizeof(mc_header)) + break; + mc_header = (struct microcode_header_intel *)ucode_ptr; mc_size = get_totalsize(mc_header);