From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40512) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bnYaX-0000zx-F6 for qemu-devel@nongnu.org; Fri, 23 Sep 2016 18:04:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bnYaW-0003oo-6E for qemu-devel@nongnu.org; Fri, 23 Sep 2016 18:04:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51942) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bnYaW-0003og-08 for qemu-devel@nongnu.org; Fri, 23 Sep 2016 18:04:56 -0400 Date: Sat, 24 Sep 2016 01:04:54 +0300 From: "Michael S. Tsirkin" Message-ID: <1474668213-15643-15-git-send-email-mst@redhat.com> References: <1474668213-15643-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1474668213-15643-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PULL v2 14/19] virtio: handle virtqueue_num_heads() errors List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , Stefan Hajnoczi , Cornelia Huck From: Stefan Hajnoczi 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 Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin 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 82142c6..b7ac356 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -347,9 +347,9 @@ 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. */ @@ -417,7 +417,7 @@ 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; @@ -478,6 +478,11 @@ 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; -- MST