[PATCH 4.19 086/134] serial: max310x: Fix to avoid potential NULL pointer dereference

[Greg Kroah-Hartman]

4.19-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
@@ -1419,6 +1419,8 @@ 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 {