usb-bus: Don't allow attaching a device to a bus with no free ports

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

diff --git a/hw/usb-bus.c b/hw/usb-bus.c
index 480956dfcf0aecd7f91a4394c50d21721dda6f7c..0a49921c0caf087543b29970797eefa95f4eda09 100644 (file)
--- a/hw/usb-bus.c
+++ b/hw/usb-bus.c
@@ -181,6 +181,11 @@ static void do_attach(USBDevice *dev)
                 dev->product_desc);
         return;
     }
+    if (bus->nfree == 0) {
+        fprintf(stderr, "Warning: tried to attach usb device %s to a bus with no free ports\n",
+                dev->product_desc);
+        return;
+    }
     if (dev->port_path) {
         QTAILQ_FOREACH(port, &bus->free, next) {
             if (strcmp(port->path, dev->port_path) == 0) {