[PATCH 7/9] iio: adc: ti-ads1018: reject devices without match data

[Jiale Yao]

SPI driver_override allows a device to bind to this driver without
matching either the OF or SPI device ID table. In that case,
spi_get_device_match_data() returns NULL.

ads1018_spi_probe() immediately dereferences the returned chip
information to initialize the IIO device, causing a NULL pointer
dereference.

Commit 572a00852635 ("iio: dac: ad5686: missing NULL check on match
data") fixed the same driver_override issue in another SPI driver.
Reject devices without match data before allocating the IIO device.

Fixes: bf0bba486b5b ("iio: adc: Add ti-ads1018 driver")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jiale Yao <yaojiale02@xxxxxxx>
---
 drivers/iio/adc/ti-ads1018.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ti-ads1018.c b/drivers/iio/adc/ti-ads1018.c
index d9ec4a8d7ce5..8f2d03eee77b 100644
--- a/drivers/iio/adc/ti-ads1018.c
+++ b/drivers/iio/adc/ti-ads1018.c
@@ -624,12 +624,16 @@ static int ads1018_trigger_setup(struct iio_dev *indio_dev)
 
 static int ads1018_spi_probe(struct spi_device *spi)
 {
-	const struct ads1018_chip_info *info = spi_get_device_match_data(spi);
+	const struct ads1018_chip_info *info;
 	struct device *dev = &spi->dev;
 	struct iio_dev *indio_dev;
 	struct ads1018 *ads1018;
 	int ret;
 
+	info = spi_get_device_match_data(spi);
+	if (!info)
+		return -ENODATA;
+
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*ads1018));
 	if (!indio_dev)
 		return -ENOMEM;
-- 
2.34.1