From patchwork Wed Aug 6 20:38:54 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Roth X-Patchwork-Id: 377598 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 3ACF51400D6 for ; Thu, 7 Aug 2014 07:16:54 +1000 (EST) Received: from localhost ([::1]:41323 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XF8Zo-0005Ii-2V for incoming@patchwork.ozlabs.org; Wed, 06 Aug 2014 17:16:52 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37991) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XF82v-00089u-Tf for qemu-devel@nongnu.org; Wed, 06 Aug 2014 16:43:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XF82k-0005Dw-EI for qemu-devel@nongnu.org; Wed, 06 Aug 2014 16:42:53 -0400 Received: from e36.co.us.ibm.com ([32.97.110.154]:45503) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XF82k-0005C1-1W for qemu-devel@nongnu.org; Wed, 06 Aug 2014 16:42:42 -0400 Received: from /spool/local by e36.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 6 Aug 2014 14:42:41 -0600 Received: from d03dlp02.boulder.ibm.com (9.17.202.178) by e36.co.us.ibm.com (192.168.1.136) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 6 Aug 2014 14:42:39 -0600 Received: from b03cxnp08025.gho.boulder.ibm.com (b03cxnp08025.gho.boulder.ibm.com [9.17.130.17]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id EC6213E40040; Wed, 6 Aug 2014 14:42:38 -0600 (MDT) Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by b03cxnp08025.gho.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s76Kgcb29961812; Wed, 6 Aug 2014 22:42:38 +0200 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s76Kgc08014721; Wed, 6 Aug 2014 14:42:38 -0600 Received: from localhost ([9.80.101.111]) by d03av04.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id s76KgbKQ014683; Wed, 6 Aug 2014 14:42:38 -0600 From: Michael Roth To: qemu-devel@nongnu.org Date: Wed, 6 Aug 2014 15:38:54 -0500 Message-Id: <1407357598-21541-45-git-send-email-mdroth@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1407357598-21541-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1407357598-21541-1-git-send-email-mdroth@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14080620-3532-0000-0000-000003A76591 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 32.97.110.154 Cc: qemu-stable@nongnu.org Subject: [Qemu-devel] [PATCH 044/108] virtio: allow mapping up to max queue size 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 From: "Michael S. Tsirkin" It's a loop from i < num_sg and the array is VIRTQUEUE_MAX_SIZE - so it's OK if the value read is VIRTQUEUE_MAX_SIZE. Not a big problem in practice as people don't use such big queues, but it's inelegant. Reported-by: "Dr. David Alan Gilbert" Cc: qemu-stable@nongnu.org Signed-off-by: Michael S. Tsirkin (cherry picked from commit 937251408051e0489f78e4db3c92e045b147b38b) Signed-off-by: Michael Roth --- hw/virtio/virtio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index abfc4e9..6523e62 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -430,7 +430,7 @@ void virtqueue_map_sg(struct iovec *sg, hwaddr *addr, unsigned int i; hwaddr len; - if (num_sg >= VIRTQUEUE_MAX_SIZE) { + if (num_sg > VIRTQUEUE_MAX_SIZE) { error_report("virtio: map attempt out of bounds: %zd > %d", num_sg, VIRTQUEUE_MAX_SIZE); exit(1);