diff --git a/arch/um/drivers/net_user.c b/arch/um/drivers/net_user.c
index 9415dd9e63ef..520118888f16 100644
--- a/arch/um/drivers/net_user.c
+++ b/arch/um/drivers/net_user.c
@@ -228,7 +228,10 @@ static void change(char *dev, char *what, unsigned char *addr,
 		       "buffer\n");
 
 	pid = change_tramp(argv, output, output_len);
-	if (pid < 0) return;
+	if (pid < 0) {
+		kfree(output);
+		return;
+	}
 
 	if (output != NULL) {
 		printk("%s", output);