[PATCH 4.14 153/165] serial: mxs-auart: Fix out-of-bounds access through serial port index

From: Greg Kroah-Hartman
Date: Thu May 24 2018 - 05:06:01 EST


4.14-stable review patch. If anyone has any objections, please let me know.

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

From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

[ Upstream commit dd345a31bfdec350d2593e6de5964e55c7f19c76 ]

The auart_port[] 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: 1ea6607d4cdc9179 ("serial: mxs-auart: Allow device tree probing")
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/mxs-auart.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -1667,6 +1667,10 @@ static int mxs_auart_probe(struct platfo
s->port.line = pdev->id < 0 ? 0 : pdev->id;
else if (ret < 0)
return ret;
+ if (s->port.line >= ARRAY_SIZE(auart_port)) {
+ dev_err(&pdev->dev, "serial%d out of range\n", s->port.line);
+ return -EINVAL;
+ }

if (of_id) {
pdev->id_entry = of_id->data;