diff --git a/4.18/wacom_wac.c b/4.18/wacom_wac.c
index e672dc12..c4c8d500 100644
--- a/4.18/wacom_wac.c
+++ b/4.18/wacom_wac.c
@@ -1224,10 +1224,20 @@ static int wacom_intuos_bt_irq(struct wacom_wac *wacom, size_t len)
 
 	switch (data[0]) {
 	case 0x04:
+		if (len < 32) {
+			dev_warn(wacom->pen_input->dev.parent,
+				 "Report 0x04 too short: %zu bytes\n", len);
+			break;
+		}
 		wacom_intuos_bt_process_data(wacom, data + i);
 		i += 10;
 		fallthrough;
 	case 0x03:
+		if (i == 1 && len < 22) {
+			dev_warn(wacom->pen_input->dev.parent,
+				 "Report 0x03 too short: %zu bytes\n", len);
+			break;
+		}
 		wacom_intuos_bt_process_data(wacom, data + i);
 		i += 10;
 		wacom_intuos_bt_process_data(wacom, data + i);