1 files changed, 7 insertions, 0 deletions
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 613d8c6615..771411ea3c 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -35,6 +35,8 @@
 #include "trace.h"
 #include "hw/s390x/css-bridge.h"
 
+#define NR_CLASSIC_INDICATOR_BITS 64
+
 static void virtio_ccw_bus_new(VirtioBusState *bus, size_t bus_size,
                                VirtioCcwDevice *dev);
 
@@ -509,6 +511,11 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
             ret = -ENOSYS;
             break;
         }
+        if (virtio_get_num_queues(vdev) > NR_CLASSIC_INDICATOR_BITS) {
+            /* More queues than indicator bits --> trigger a reject */
+            ret = -ENOSYS;
+            break;
+        }
         if (!ccw.cda) {
             ret = -EFAULT;
         } else {