3.16.60-rc1 review patch. If anyone has any objections, please let me know.
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From: Geert Uytterhoeven geert+renesas@glider.be
commit f9f5786987e81d166c60833edcb7d1836aa16944 upstream.
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 geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [bwh: Backported to 3.16: Put the check in arc_uart_init_one() and move initialisation of the uart variable below it] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- --- a/drivers/tty/serial/arc_uart.c +++ b/drivers/tty/serial/arc_uart.c @@ -531,8 +531,14 @@ arc_uart_init_one(struct platform_device { struct resource *res, *res2; unsigned long *plat_data; - struct arc_uart_port *uart = &arc_uart_ports[dev_id]; + struct arc_uart_port *uart;
+ 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]; plat_data = dev_get_platdata(&pdev->dev); if (!plat_data) return -ENODEV;