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

The cdns_uart_port[] 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.

Fixes: 928e926349 ("tty: xuartps: Initialize ports according to aliases")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Geert Uytterhoeven 2018-02-23 14:38:37 +01:00 committed by Greg Kroah-Hartman
parent 96c611c2b7
commit e7d75e18d0

View File

@ -1110,7 +1110,7 @@ static struct uart_port *cdns_uart_get_port(int id)
struct uart_port *port;
/* Try the given port id if failed use default method */
if (cdns_uart_port[id].mapbase != 0) {
if (id < CDNS_UART_NR_PORTS && cdns_uart_port[id].mapbase != 0) {
/* Find the next unused port */
for (id = 0; id < CDNS_UART_NR_PORTS; id++)
if (cdns_uart_port[id].mapbase == 0)