The sci_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_SH_SCI_NR_UARTS), so this can even be triggered using a
legitimate DTB.

Fixes: 97ed9790c514066b ("serial: sh-sci: Remove unused platform data 
capabilities field")
Signed-off-by: Geert Uytterhoeven <geert+rene...@glider.be>
---
v2:
  - Fix Fixes reference,
  - Use ARRAY_SIZE().
---
 drivers/tty/serial/sh-sci.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 4d14f321cbec95e0..f6a6610d434efc33 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -3096,6 +3096,10 @@ static struct plat_sci_port *sci_parse_dt(struct 
platform_device *pdev,
                dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
                return NULL;
        }
+       if (id >= ARRAY_SIZE(sci_ports)) {
+               dev_err(&pdev->dev, "serial%d out of range\n", id);
+               return NULL;
+       }
 
        sp = &sci_ports[id];
        *dev_id = id;
-- 
2.7.4

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