From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932409Ab1KSAK5 (ORCPT ); Fri, 18 Nov 2011 19:10:57 -0500 Received: from cantor2.suse.de ([195.135.220.15]:38940 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932328Ab1KSAKx (ORCPT ); Fri, 18 Nov 2011 19:10:53 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Fri Nov 18 16:03:29 2011 Message-Id: <20111119000329.688892178@clark.kroah.org> User-Agent: quilt/0.48-20.1.2 Date: Fri, 18 Nov 2011 16:02:56 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Dan Carpenter , Konrad Rzeszutek Wilk Subject: [20/26] xen-gntalloc: integer overflow in gntalloc_ioctl_alloc() In-Reply-To: <20111119000336.GA8452@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit 21643e69a4c06f7ef155fbc70e3fba13fba4a756 upstream. On 32 bit systems a high value of op.count could lead to an integer overflow in the kzalloc() and gref_ids would be smaller than expected. If the you triggered another integer overflow in "if (gref_size + op.count > limit)" then you'd probably get memory corruption inside add_grefs(). Signed-off-by: Dan Carpenter Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman --- drivers/xen/gntalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/xen/gntalloc.c +++ b/drivers/xen/gntalloc.c @@ -280,7 +280,7 @@ static long gntalloc_ioctl_alloc(struct goto out; } - gref_ids = kzalloc(sizeof(gref_ids[0]) * op.count, GFP_TEMPORARY); + gref_ids = kcalloc(op.count, sizeof(gref_ids[0]), GFP_TEMPORARY); if (!gref_ids) { rc = -ENOMEM; goto out;