From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51801) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYq6E-00041r-BH for qemu-devel@nongnu.org; Fri, 20 Mar 2015 02:08:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YYq69-0000gE-Ky for qemu-devel@nongnu.org; Fri, 20 Mar 2015 02:08:02 -0400 From: Jason Wang Date: Fri, 20 Mar 2015 14:07:50 +0800 Message-Id: <1426831670-11080-1-git-send-email-jasowang@redhat.com> Subject: [Qemu-devel] [PATCH for 2.3 V2] virtio-net: validate backend queue numbers against bus limitation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Jason Wang , qemu-stable , mst@redhat.com We don't validate the backend queue numbers against bus limitation, this will easily crash qemu if it exceeds the limitation which will hit the abort() in virtio_del_queue(). An example is trying to starting a virtio-net device with 256 queues. E.g: ./qemu-system-x86_64 -netdev tap,id=hn0,queues=256 -device virtio-net-pci,netdev=hn0 Fixing this by doing the validation and fail early. Cc: Michael S. Tsirkin Cc: qemu-stable Signed-off-by: Jason Wang --- Changes from V1: Tweak the commit log. --- hw/net/virtio-net.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 27adcc5..59f76bc 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -1588,6 +1588,13 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, n->config_size); n->max_queues = MAX(n->nic_conf.peers.queues, 1); + if (n->max_queues * 2 + 1 > VIRTIO_PCI_QUEUE_MAX) { + error_setg(errp, "Invalid number of queues (= %" PRIu32 "), " + "must be a postive integer less than %d.", + n->max_queues, (VIRTIO_PCI_QUEUE_MAX - 1) / 2); + virtio_cleanup(vdev); + return; + } n->vqs = g_malloc0(sizeof(VirtIONetQueue) * n->max_queues); n->vqs[0].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx); n->curr_queues = 1; -- 2.1.0