From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751417AbaHZPir (ORCPT ); Tue, 26 Aug 2014 11:38:47 -0400 Received: from mail-pd0-f181.google.com ([209.85.192.181]:51593 "EHLO mail-pd0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750823AbaHZPip (ORCPT ); Tue, 26 Aug 2014 11:38:45 -0400 Message-ID: <53FCAA04.40009@gmail.com> Date: Tue, 26 Aug 2014 23:38:44 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, david.vrabel@citrix.com CC: xen-devel@lists.xenproject.org, "linux-kernel@vger.kernel.org" Subject: [PATCH] drivers/xen/grant-table.c: Be sure of unsigned value never comparing with 0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In grow_gnttab_list(), 'i' is 'unsigned int', and 'nr_glist_frames' may be 0 because 'nr_grant_frames' may be 0. So 'i' may never be less than 'nr_glist_frames' in failure processing, which cause infinite looping. Signed-off-by: Chen Gang --- drivers/xen/grant-table.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index c254ae0..be07645 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -592,8 +592,8 @@ static int grow_gnttab_list(unsigned int more_frames) return 0; grow_nomem: - for ( ; i >= nr_glist_frames; i--) - free_page((unsigned long) gnttab_list[i]); + while (i > nr_glist_frames) + free_page((unsigned long) gnttab_list[--i]); return -ENOMEM; } -- 1.9.3