From patchwork Tue Apr 12 13:25:33 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 609420 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3qknsw2HNYz9t57 for ; Tue, 12 Apr 2016 23:32:20 +1000 (AEST) Received: from localhost ([::1]:49587 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1apyQU-0008VZ-E5 for incoming@patchwork.ozlabs.org; Tue, 12 Apr 2016 09:32:18 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45052) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1apyKT-00036P-Em for qemu-devel@nongnu.org; Tue, 12 Apr 2016 09:26:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1apyKP-0005WH-8z for qemu-devel@nongnu.org; Tue, 12 Apr 2016 09:26:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48030) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1apyKO-0005WA-2E for qemu-devel@nongnu.org; Tue, 12 Apr 2016 09:26:01 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id BA29C81103; Tue, 12 Apr 2016 13:25:59 +0000 (UTC) Received: from localhost (ovpn-112-60.ams2.redhat.com [10.36.112.60]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u3CDPwd9016153; Tue, 12 Apr 2016 09:25:59 -0400 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Date: Tue, 12 Apr 2016 14:25:33 +0100 Message-Id: <1460467534-29147-10-git-send-email-stefanha@redhat.com> In-Reply-To: <1460467534-29147-1-git-send-email-stefanha@redhat.com> References: <1460467534-29147-1-git-send-email-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v3 09/10] virtio: handle virtqueue_num_heads() errors X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Cornelia Huck , Fam Zheng , Stefan Hajnoczi , "Michael S. Tsirkin" Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" If the avail ring index is bogus virtqueue_num_heads() must return -EINVAL. The only caller is virtqueue_get_avail_bytes(). Return saying no bytes are available when virtqueue_num_heads() fails. Signed-off-by: Stefan Hajnoczi Reviewed-by: Cornelia Huck --- hw/virtio/virtio.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 58599cf..4fe342a 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -323,9 +323,9 @@ static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) /* Check it isn't doing very strange things with descriptor numbers. */ if (num_heads > vq->vring.num) { - error_report("Guest moved used index from %u to %u", + virtio_error(vq->vdev, "Guest moved used index from %u to %u", idx, vq->shadow_avail_idx); - exit(1); + return -EINVAL; } /* On success, callers read a descriptor at vq->last_avail_idx. * Make sure descriptor read does not bypass avail index read. */ @@ -393,7 +393,7 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, idx = vq->last_avail_idx; total_bufs = in_total = out_total = 0; - while (virtqueue_num_heads(vq, idx)) { + while ((rc = virtqueue_num_heads(vq, idx)) > 0) { VirtIODevice *vdev = vq->vdev; unsigned int max, num_bufs, indirect = 0; VRingDesc desc; @@ -454,6 +454,11 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, else total_bufs++; } + + if (rc < 0) { + goto err; + } + done: if (in_bytes) { *in_bytes = in_total;