Commit f9f57869 authored Feb 23, 2018 by Geert Uytterhoeven Committed by Greg Kroah-Hartman Feb 28, 2018

serial: arc_uart: Fix out-of-bounds access through DT alias



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

Fix this by adding a range check.

Note that the array size is defined by a Kconfig symbol
(CONFIG_SERIAL_ARC_NR_PORTS), so this can even be triggered using a
legitimate DTB.

Fixes: ea28fd56 ("serial/arc-uart: switch to devicetree based probing")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 42afa627

drivers/tty/serial/arc_uart.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -593,6 +593,11 @@ static int arc_serial_probe(struct platform_device *pdev)
		if (dev_id < 0)
		dev_id = 0;

		if (dev_id >= ARRAY_SIZE(arc_uart_ports)) {
		dev_err(&pdev->dev, "serial%d out of range\n", dev_id);
		return -EINVAL;
		}

		uart = &arc_uart_ports[dev_id];
		port = &uart->port;