[PATCH 3.16 020/366] serial: imx: Fix out-of-bounds access through serial port index

[Ben Hutchings]

3.16.60-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

commit 5673444821406dda5fc25e4b52aca419f8065a19 upstream.

The imx_ports[] array is indexed using a value derived from the
"serialN" alias in DT, or from platform data, which may lead to an
out-of-bounds access.

Fix this by adding a range check.

Fixes: ff05967a07225ab6 ("serial/imx: add of_alias_get_id() reference back")
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Reviewed-by: Uwe Kleine-KÃnig <u.kleine-koenig@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/tty/serial/imx.c | 6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1919,6 +1919,12 @@ static int serial_imx_probe(struct platf
 	else if (ret < 0)
 		return ret;
 
+	if (sport->port.line >= ARRAY_SIZE(imx_ports)) {
+		dev_err(&pdev->dev, "serial%d out of range\n",
+			sport->port.line);
+		return -EINVAL;
+	}
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(base))