diff --git a/drivers/usb/usbip/usbip_common.c b/drivers/usb/usbip/usbip_common.c
index 8ebaaeaf848e..a5837c0feb05 100644
--- a/drivers/usb/usbip/usbip_common.c
+++ b/drivers/usb/usbip/usbip_common.c
@@ -470,6 +470,18 @@ static void usbip_pack_ret_submit(struct usbip_header *pdu, struct urb *urb,
 		urb->status		= rpdu->status;
 		urb->actual_length	= rpdu->actual_length;
 		urb->start_frame	= rpdu->start_frame;
+		/*
+		 * The number_of_packets field determines the length of
+		 * iso_frame_desc[], which is a flexible array allocated
+		 * at URB creation time. A response must never claim more
+		 * packets than originally submitted; doing so would cause
+		 * an out-of-bounds write in usbip_recv_iso() and
+		 * usbip_pad_iso(). Clamp to zero on violation so both
+		 * functions safely return early.
+		 */
+		if (rpdu->number_of_packets < 0 ||
+		    rpdu->number_of_packets > urb->number_of_packets)
+			rpdu->number_of_packets = 0;
 		urb->number_of_packets = rpdu->number_of_packets;
 		urb->error_count	= rpdu->error_count;
 	}