From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cyrill Gorcunov Subject: Re: [patch 1/5] x86: ACPI - add checking for NULL early param Date: Tue, 22 Jul 2008 14:19:45 +0400 Message-ID: <20080722101945.GA6699@lenovo> References: <20080705115334.892720771@gmail.com> <486f61a9.2135440a.0d16.ffffbd7f@mx.google.com> <20080722025332.afddd49b.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from nf-out-0910.google.com ([64.233.182.190]:52423 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752921AbYGVKTw (ORCPT ); Tue, 22 Jul 2008 06:19:52 -0400 Received: by nf-out-0910.google.com with SMTP id d3so632643nfc.21 for ; Tue, 22 Jul 2008 03:19:48 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20080722025332.afddd49b.akpm@linux-foundation.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Andrew Morton Cc: mingo@elte.hu, hpa@zytor.com, tglx@linutronix.de, andi@firstfloor.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org [Andrew Morton - Tue, Jul 22, 2008 at 02:53:32AM -0700] | On Sat, 05 Jul 2008 15:53:35 +0400 Cyrill Gorcunov wrote: | | > Signed-off-by: Cyrill Gorcunov | > --- | > | > Index: linux-2.6.git/drivers/acpi/tables.c | > ==================================================================== | > --- linux-2.6.git.orig/drivers/acpi/tables.c 2008-01-21 23:14:47.000000000 +0300 | > +++ linux-2.6.git/drivers/acpi/tables.c 2008-07-05 12:24:16.000000000 +0400 | > @@ -300,6 +300,8 @@ int __init acpi_table_init(void) | > | > static int __init acpi_parse_apic_instance(char *str) | > { | > + if (!str) | > + return -EINVAL; | > | > acpi_apic_instance = simple_strtoul(str, NULL, 0); | > | | Could you please explain this patch? | we could get NULL deref here - if you start kernel as qemu-system-x86_64 -kernel arch/x86/boot/bzImage -append "root=/dev/sda acpi_apic_instance" ../images/root-j so user was not carried about correct boot option and the kernel respond by hang - which is not good I think. Actually - by the patch we easy protect ourself from user-madness :) - Cyrill -