serial: imx: Fix out-of-bounds access through serial port index

[ Upstream commit 5673444821406dda5fc25e4b52aca419f8065a19 ]

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@glider.be>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 98176d1..07ede98 100644 (file)
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1923,6 +1923,12 @@ static int serial_imx_probe(struct platform_device *pdev)
        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))