diff --git a/drivers/of/device.c b/drivers/of/device.c
index 9d0895fb53b5a7..c5c06997fdd2a1 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -257,6 +257,8 @@ ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
 	ssize_t sl = of_device_get_modalias(dev, str, len - 2);
 	if (sl < 0)
 		return sl;
+	if (sl > len - 2)
+		return -ENOMEM;
 
 	str[sl++] = '\n';
 	str[sl] = 0;