diff --git a/hw/usb.h b/hw/usb.h
index 00d2802..efd4a65 100644
--- a/hw/usb.h
+++ b/hw/usb.h
@@ -117,6 +117,14 @@
 #define USB_DT_INTERFACE		0x04
 #define USB_DT_ENDPOINT			0x05
 
+/*
+ * Descriptor sizes per descriptor type
+ */
+#define USB_DT_DEVICE_SIZE		18
+#define USB_DT_CONFIG_SIZE		9
+#define USB_DT_INTERFACE_SIZE		9
+#define USB_DT_ENDPOINT_SIZE		7
+
 #define USB_ENDPOINT_XFER_CONTROL	0
 #define USB_ENDPOINT_XFER_ISOC		1
 #define USB_ENDPOINT_XFER_BULK		2
diff --git a/usb-linux.c b/usb-linux.c
index 88273ff..d259290 100644
--- a/usb-linux.c
+++ b/usb-linux.c
@@ -299,7 +299,7 @@ static int usb_host_claim_interfaces(USBHostDevice *dev, int configuration)
 
     i = 0;
     dev_descr_len = dev->descr[0];
-    if (dev_descr_len > dev->descr_len) {
+    if ( dev_descr_len < USB_DT_DEVICE_SIZE || dev_descr_len > dev->descr_len) {
         goto fail;
     }
 
@@ -314,6 +314,8 @@ static int usb_host_claim_interfaces(USBHostDevice *dev, int configuration)
             continue;
         }
         config_descr_len = dev->descr[i];
+        if ( config_descr_len < USB_DT_CONFIG_SIZE )
+            goto fail;
 
         printf("husb: config #%d need %d\n", dev->descr[i + 5], configuration);