4.9-stable review patch. If anyone has any objections, please let me know.
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From: Geert Uytterhoeven geert+renesas@glider.be
[ 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 geert+renesas@glider.be Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/tty/serial/arc_uart.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/tty/serial/arc_uart.c +++ b/drivers/tty/serial/arc_uart.c @@ -596,6 +596,11 @@ static int arc_serial_probe(struct platf 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;