[PATCH 3.16 022/366] serial: pxa: Fix out-of-bounds access through serial port index

[Ben Hutchings]

3.16.60-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Geert Uytterhoeven <geert+rene...@glider.be>

commit afc7851fab8329eddcf321c9e0a58c893f351dd6 upstream.

The serial_pxa_ports[] array is indexed using a value derived from the
"serialN" alias in DT, or from platform data, which may lead to an
out-of-bounds access.

Fix this by adding a range check.

Fixes: 699c20f3e6310aa2 ("serial: pxa: add OF support")
Signed-off-by: Geert Uytterhoeven <geert+rene...@glider.be>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/tty/serial/pxa.c | 4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/tty/serial/pxa.c
+++ b/drivers/tty/serial/pxa.c
@@ -888,6 +888,10 @@ static int serial_pxa_probe(struct platf
                sport->port.line = dev->id;
        else if (ret < 0)
                goto err_clk;
+       if (sport->port.line >= ARRAY_SIZE(serial_pxa_ports)) {
+               dev_err(&dev->dev, "serial%d out of range\n", sport->port.line);
+               return -EINVAL;
+       }
        snprintf(sport->name, PXA_NAME_LEN - 1, "UART%d", sport->port.line + 1);
 
        sport->port.membase = ioremap(mmres->start, resource_size(mmres));