Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751999AbdGYV3l (ORCPT ); Tue, 25 Jul 2017 17:29:41 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60826 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751817AbdGYTR3 (ORCPT ); Tue, 25 Jul 2017 15:17:29 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Seunghun Han , Thomas Gleixner , security@kernel.org, "Rafael J. Wysocki" , Ingo Molnar Subject: [PATCH 3.18 40/60] x86/acpi: Prevent out of bound access caused by broken ACPI tables Date: Tue, 25 Jul 2017 12:16:31 -0700 Message-Id: <20170725191619.765711364@linuxfoundation.org> X-Mailer: git-send-email 2.13.3 In-Reply-To: <20170725191614.043749784@linuxfoundation.org> References: <20170725191614.043749784@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1445 Lines: 49 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Seunghun Han commit dad5ab0db8deac535d03e3fe3d8f2892173fa6a4 upstream. The bus_irq argument of mp_override_legacy_irq() is used as the index into the isa_irq_to_gsi[] array. The bus_irq argument originates from ACPI_MADT_TYPE_IO_APIC and ACPI_MADT_TYPE_INTERRUPT items in the ACPI tables, but is nowhere sanity checked. That allows broken or malicious ACPI tables to overwrite memory, which might cause malfunction, panic or arbitrary code execution. Add a sanity check and emit a warning when that triggers. [ tglx: Added warning and rewrote changelog ] Signed-off-by: Seunghun Han Signed-off-by: Thomas Gleixner Cc: security@kernel.org Cc: "Rafael J. Wysocki" Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/acpi/boot.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -316,6 +316,14 @@ static void __init mp_override_legacy_ir struct mpc_intsrc mp_irq; /* + * Check bus_irq boundary. + */ + if (bus_irq >= NR_IRQS_LEGACY) { + pr_warn("Invalid bus_irq %u for legacy override\n", bus_irq); + return; + } + + /* * Convert 'gsi' to 'ioapic.pin'. */ ioapic = mp_find_ioapic(gsi);