From patchwork Mon Dec 30 05:29:08 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hu Tao X-Patchwork-Id: 305701 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 499D02C0256 for ; Mon, 30 Dec 2013 16:32:14 +1100 (EST) Received: from localhost ([::1]:57207 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VxVSU-0006r6-Ut for incoming@patchwork.ozlabs.org; Mon, 30 Dec 2013 00:32:10 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44412) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VxVRt-0006q4-QP for qemu-devel@nongnu.org; Mon, 30 Dec 2013 00:31:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VxVRp-00019V-7g for qemu-devel@nongnu.org; Mon, 30 Dec 2013 00:31:33 -0500 Received: from [222.73.24.84] (port=49495 helo=song.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VxVRo-00018T-Tr for qemu-devel@nongnu.org; Mon, 30 Dec 2013 00:31:29 -0500 X-IronPort-AV: E=Sophos;i="4.95,571,1384272000"; d="scan'208";a="9349126" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 30 Dec 2013 13:27:37 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id rBU5VAO0005712; Mon, 30 Dec 2013 13:31:10 +0800 Received: from G08FNSTD100614.fnst.cn.fujitsu.com ([10.167.226.102]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2013123013302259-761719 ; Mon, 30 Dec 2013 13:30:22 +0800 From: Hu Tao To: qemu-devel@nongnu.org Date: Mon, 30 Dec 2013 13:29:08 +0800 Message-Id: X-Mailer: git-send-email 1.7.11.7 In-Reply-To: References: X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/12/30 13:30:22, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/12/30 13:30:25, Serialize complete at 2013/12/30 13:30:25 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 222.73.24.84 Cc: Kevin Wolf , Stefan Hajnoczi Subject: [Qemu-devel] [PATCH v1 2/3] qcow2: fix offset overflow X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org When cluster size is big enough it can lead offset overflow in qcow2_alloc_clusters_at(). This patch fixes it. Signed-off-by: Hu Tao --- block/qcow2-refcount.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index c974abe..b3ebb7f 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -676,7 +676,12 @@ int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, BDRVQcowState *s = bs->opaque; uint64_t cluster_index; uint64_t old_free_cluster_index; - int i, refcount, ret; + uint64_t i; + int refcount, ret; + + if (nb_clusters <= 0) { + return 0; + } /* Check how many clusters there are free */ cluster_index = offset >> s->cluster_bits;