From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Fri, 23 Feb 2018 13:38:32 +0000 (+0100)
Subject: serial: mxs-auart: Fix out-of-bounds access through serial port index
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=5f53807e751ef0b01e56d46d06d1f1a5828de249;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

serial: mxs-auart: Fix out-of-bounds access through serial port index

[ 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@glider.be>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index be94246b6fcc..673c8fd7e34f 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -1667,6 +1667,10 @@ static int mxs_auart_probe(struct platform_device *pdev)
 		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;