From f9f5786987e81d166c60833edcb7d1836aa16944 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 23 Feb 2018 14:38:29 +0100 Subject: [PATCH] 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: ea28fd56fcde69af ("serial/arc-uart: switch to devicetree based probing") Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/arc_uart.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c index 2599f9ecccfe..d904a3a345e7 100644 --- a/drivers/tty/serial/arc_uart.c +++ b/drivers/tty/serial/arc_uart.c @@ -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;