From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754548AbZGSODA (ORCPT ); Sun, 19 Jul 2009 10:03:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754437AbZGSOC7 (ORCPT ); Sun, 19 Jul 2009 10:02:59 -0400 Received: from mail-yx0-f184.google.com ([209.85.210.184]:54728 "EHLO mail-yx0-f184.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754357AbZGSOC7 (ORCPT ); Sun, 19 Jul 2009 10:02:59 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:x-x-sender:to:subject:message-id:user-agent:mime-version :content-type; b=bTTDsxyWvs77SY2KRM++o/PhmUyQ9G8qBFC4n1IOQbYqndUbPIiuCbkcxI5ZYLYEJ2 R/UWSk2bdsYDpv3kJZIvwkEpvnvM5NE96c2nokTYnIEv6f0+KTMCzgmuYBaBXbyO0XF6 Wq5bIfWQv2hSwG6ymVydJxt1MokmlLlF1ER7c= Date: Sun, 19 Jul 2009 16:04:48 +0300 (EAT) From: Dan Carpenter X-X-Sender: dcarpenter@bicker To: linux-kernel@vger.kernel.org Subject: potential null dereference in sysfs_override_clocksource() Message-ID: 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 Hello, I am testing a source checker (http://repo.or.cz/w/smatch.git). It found an issue in sysfs_override_clocksource() from kernel/time/clocksource.c. If "len" is zero then "ovr" is null and checking ovr->flags will oops on line 517. kernel/time/clocksource.c 516 if (tick_oneshot_mode_active() && 517 !(ovr->flags & CLOCK_SOURCE_VALID_FOR_HRES)) { 518 printk(KERN_WARNING "%s clocksource is not HRT compatible. " regards, dan carpenter