From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752527Ab0ESOW6 (ORCPT ); Wed, 19 May 2010 10:22:58 -0400 Received: from smtp.citrix.com ([66.165.176.89]:58101 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752228Ab0ESOW5 (ORCPT ); Wed, 19 May 2010 10:22:57 -0400 X-IronPort-AV: E=Sophos;i="4.53,263,1272859200"; d="scan'208";a="8591271" Date: Wed, 19 May 2010 15:25:45 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball-desktop To: Jeremy Fitzhardinge CC: Stefano Stabellini , "linux-kernel@vger.kernel.org" , "xen-devel@lists.xensource.com" , Don Dutile , Sheng Yang Subject: Re: [PATCH 09/12] Fix possible NULL pointer dereference in print_IO_APIC In-Reply-To: <4BF2D95B.2040007@goop.org> Message-ID: References: <1274178187-20602-9-git-send-email-stefano.stabellini@eu.citrix.com> <4BF2D95B.2040007@goop.org> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 18 May 2010, Jeremy Fitzhardinge wrote: > On 05/18/2010 03:23 AM, Stefano Stabellini wrote: > > Make sure chip_data is not NULL before accessing it. > > > > You should clarify under what circumstances it can be legitimately NULL. > > The VIRQ_TIMER handler and virq handlers in general don't have any chip_data. > > Signed-off-by: Stefano Stabellini > > --- > > arch/x86/kernel/apic/io_apic.c | 2 ++ > > 1 files changed, 2 insertions(+), 0 deletions(-) > > > > diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c > > index eb2789c..c64499c 100644 > > --- a/arch/x86/kernel/apic/io_apic.c > > +++ b/arch/x86/kernel/apic/io_apic.c > > @@ -1732,6 +1732,8 @@ __apicdebuginit(void) print_IO_APIC(void) > > struct irq_pin_list *entry; > > > > cfg = desc->chip_data; > > + if (!cfg) > > + continue; > > entry = cfg->irq_2_pin; > > if (!entry) > > continue; > > >