Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758165AbXLLMNZ (ORCPT ); Wed, 12 Dec 2007 07:13:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752110AbXLLMNP (ORCPT ); Wed, 12 Dec 2007 07:13:15 -0500 Received: from aun.it.uu.se ([130.238.12.36]:58781 "EHLO aun.it.uu.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751948AbXLLMNO (ORCPT ); Wed, 12 Dec 2007 07:13:14 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18271.53321.104822.233365@harpo.it.uu.se> Date: Wed, 12 Dec 2007 13:12:57 +0100 From: Mikael Pettersson To: William Lee Irwin III Cc: Mikael Pettersson , lenb@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: acpi ->video_device_list corruption In-Reply-To: <20071212115655.GB18472@holomorphy.com> References: <20071212101505.GA18472@holomorphy.com> <18271.51833.872482.880312@harpo.it.uu.se> <20071212115655.GB18472@holomorphy.com> X-Mailer: VM 7.17 under Emacs 20.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2173 Lines: 57 William Lee Irwin III writes: > On Wed, Dec 12, 2007 at 12:48:09PM +0100, Mikael Pettersson wrote: > > IMO the memset(ptr, 0, sizeof(*ptr)) idiom is both safer > > and avoids having to write an uninteresting type name. > > How about this, then? Looks good. Acked-by: Mikael Pettersson > > The ->cap fields of struct acpi_video_device and struct acpi_video_bus > are 1B each, not 4B. The oversized memset()'s corrupted the subsequent > list_head fields. This resulted in silent corruption without > CONFIG_DEBUG_LIST and BUG's with it. This patch uses sizeof() to pass > the proper bounds to the memset() calls and thereby correct the bugs. > > The patch was seen to resolve the issue on the affected system. > > vs. 2.6.24-rc5 > > Signed-off-by: William Irwin > > diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c > index 44a0d9b..bd77e81 100644 > --- a/drivers/acpi/video.c > +++ b/drivers/acpi/video.c > @@ -577,7 +577,7 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device) > struct acpi_video_device_brightness *br = NULL; > > > - memset(&device->cap, 0, 4); > + memset(&device->cap, 0, sizeof(device->cap)); > > if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_ADR", &h_dummy1))) { > device->cap._ADR = 1; > @@ -697,7 +697,7 @@ static void acpi_video_bus_find_cap(struct acpi_video_bus *video) > { > acpi_handle h_dummy1; > > - memset(&video->cap, 0, 4); > + memset(&video->cap, 0, sizeof(video->cap)); > if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_DOS", &h_dummy1))) { > video->cap._DOS = 1; > } > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/