diff --git a/drivers/leds/led-class-multicolor.c b/drivers/leds/led-class-multicolor.c
index ec62a4811613..f3fd043cb185 100644
--- a/drivers/leds/led-class-multicolor.c
+++ b/drivers/leds/led-class-multicolor.c
@@ -42,22 +42,27 @@ static ssize_t multi_intensity_store(struct device *dev,
 
 	mutex_lock(&led_cdev->led_access);
 
-	for (i = 0; i < mcled_cdev->num_colors; i++) {
+	for (i = 0; i < LED_COLOR_ID_MAX; i++) {
 		ret = sscanf(buf + offset, "%i%n",
 			     &intensity_value[i], &nrchars);
-		if (ret != 1) {
-			ret = -EINVAL;
-			goto err_out;
-		}
+		if (ret != 1)
+			break;
 		offset += nrchars;
 	}
 
+	/* Expect newline; reject surplus trailing chars */
 	offset++;
 	if (offset < size) {
 		ret = -EINVAL;
 		goto err_out;
 	}
 
+	/* Require at least the physical number of colors */
+	if (i < mcled_cdev->num_colors) {
+		ret = -EINVAL;
+		goto err_out;
+	}
+
 	for (i = 0; i < mcled_cdev->num_colors; i++)
 		mcled_cdev->subled_info[i].intensity = intensity_value[i];