[PATCH 4/9] iio: adc: max11205: 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.

max11205_probe() immediately dereferences the returned chip information
to set the IIO device name, 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 using the chip information.

Fixes: bf3c855be801 ("iio: adc: max11205: simplify with spi_get_device_match_data()")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jiale Yao <yaojiale02@xxxxxxx>
---
 drivers/iio/adc/max11205.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iio/adc/max11205.c b/drivers/iio/adc/max11205.c
index 63b6561dcf47..53ac2f4f383e 100644
--- a/drivers/iio/adc/max11205.c
+++ b/drivers/iio/adc/max11205.c
@@ -117,6 +117,8 @@ static int max11205_probe(struct spi_device *spi)
 	ad_sd_init(&st->sd, indio_dev, spi, &max11205_sigma_delta_info);
 
 	st->chip_info = spi_get_device_match_data(spi);
+	if (!st->chip_info)
+		return -ENODATA;
 
 	indio_dev->name = st->chip_info->name;
 	indio_dev->modes = INDIO_DIRECT_MODE;
-- 
2.34.1