[PATCH 2/7] iio: dac: ad5755: validate SPI match data

[Jiale Yao <yaojiale02@163.com>]

A device bound through driver_override need not match an entry in the
driver tables. In that case spi_get_device_match_data() returns NULL,
but ad5755_probe() stores and later dereferences the result.

Validate the match data before it is used.

Fixes: 62d3fb9dcc09 ("iio: dac: ad5755: make use of of_device_id table")
Signed-off-by: Jiale Yao <yaojiale02@163.com>
---
 drivers/iio/dac/ad5755.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iio/dac/ad5755.c b/drivers/iio/dac/ad5755.c
index 0828b9909099..730289dd8ef6 100644
--- a/drivers/iio/dac/ad5755.c
+++ b/drivers/iio/dac/ad5755.c
@@ -819,6 +819,9 @@ static int ad5755_probe(struct spi_device *spi)
 	spi_set_drvdata(spi, indio_dev);
 
 	st->chip_info = spi_get_device_match_data(spi);
+	if (!st->chip_info)
+		return -ENODATA;
+
 	st->spi = spi;
 	st->pwr_down = 0xf;
 
-- 
2.34.1