[PATCH 4.4 114/131] serial: max310x: Fix to avoid potential NULL pointer dereference

From: Greg Kroah-Hartman
Date: Mon Apr 01 2019 - 13:43:56 EST


4.4-stable review patch. If anyone has any objections, please let me know.

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

From: Aditya Pakki <pakki001@xxxxxxx>

commit 3a10e3dd52e80b9a97a3346020024d17b2c272d6 upstream.

of_match_device can return a NULL pointer when matching device is not
found. This patch avoids a scenario causing NULL pointer derefernce.

Signed-off-by: Aditya Pakki <pakki001@xxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/tty/serial/max310x.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -1306,6 +1306,8 @@ static int max310x_spi_probe(struct spi_
if (spi->dev.of_node) {
const struct of_device_id *of_id =
of_match_device(max310x_dt_ids, &spi->dev);
+ if (!of_id)
+ return -ENODEV;

devtype = (struct max310x_devtype *)of_id->data;
} else {