From: Geert Uytterhoeven Date: Fri, 23 Feb 2018 13:38:29 +0000 (+0100) Subject: serial: arc_uart: Fix out-of-bounds access through DT alias X-Git-Tag: v3.18.111~15 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=8bdc529a73b72b7c2b6844d7eeb731b6369548e3;p=thirdparty%2Fkernel%2Fstable.git serial: arc_uart: Fix out-of-bounds access through DT alias [ Upstream commit f9f5786987e81d166c60833edcb7d1836aa16944 ] 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: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c index a59d1d77e7506..f6f9a039afce9 100644 --- a/drivers/tty/serial/arc_uart.c +++ b/drivers/tty/serial/arc_uart.c @@ -597,6 +597,11 @@ 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;