From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933077Ab3E1DzS (ORCPT ); Mon, 27 May 2013 23:55:18 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52618 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758878Ab3E1DyM (ORCPT ); Mon, 27 May 2013 23:54:12 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Lv Zheng" , "Rafael J. Wysocki" , "Bob Moore" Date: Tue, 28 May 2013 04:49:53 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [16/94] ACPICA: Fix possible buffer overflow during a field unit read operation In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.101 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.46-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Bob Moore commit 61388f9e5d93053cf399a356414f31f9b4814c6d upstream. Can only happen under these conditions: 1) The DSDT version is 1, meaning integers are 32-bits. 2) The field is between 33 and 64 bits long. It applies cleanly back to ACPICA 20100806+ (Linux v2.6.37+). Signed-off-by: Bob Moore Signed-off-by: Lv Zheng Signed-off-by: Rafael J. Wysocki Signed-off-by: Ben Hutchings --- drivers/acpi/acpica/exfldio.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) --- a/drivers/acpi/acpica/exfldio.c +++ b/drivers/acpi/acpica/exfldio.c @@ -702,7 +702,19 @@ acpi_ex_extract_from_field(union acpi_op if ((obj_desc->common_field.start_field_bit_offset == 0) && (obj_desc->common_field.bit_length == access_bit_width)) { - status = acpi_ex_field_datum_io(obj_desc, 0, buffer, ACPI_READ); + if (buffer_length >= sizeof(u64)) { + status = + acpi_ex_field_datum_io(obj_desc, 0, buffer, + ACPI_READ); + } else { + /* Use raw_datum (u64) to handle buffers < 64 bits */ + + status = + acpi_ex_field_datum_io(obj_desc, 0, &raw_datum, + ACPI_READ); + ACPI_MEMCPY(buffer, &raw_datum, buffer_length); + } + return_ACPI_STATUS(status); }