diff --git a/drivers/tty/serial/sirfsoc_uart.c b/drivers/tty/serial/sirfsoc_uart.c
index 9925b00a9777..38622f2a30a9 100644
--- a/drivers/tty/serial/sirfsoc_uart.c
+++ b/drivers/tty/serial/sirfsoc_uart.c
@@ -1283,6 +1283,11 @@ static int sirfsoc_uart_probe(struct platform_device *pdev)
 		goto err;
 	}
 	sirfport->port.line = of_alias_get_id(np, "serial");
+	if (sirfport->port.line >= ARRAY_SIZE(sirf_ports)) {
+		dev_err(&pdev->dev, "serial%d out of range\n",
+			sirfport->port.line);
+		return -EINVAL;
+	}
 	sirf_ports[sirfport->port.line] = sirfport;
 	sirfport->port.iotype = UPIO_MEM;
 	sirfport->port.flags = UPF_BOOT_AUTOCONF;