[PATCH 6.18.y 2/2] iio: adc: ad7192: reject devices without match data

[Sasha Levin <sashal@kernel.org>]

From: Jiale Yao <yaojiale02@163.com>

[ Upstream commit 7f7a119a370ecf6c8d4ab9e9ee0a8cdd77afedd3 ]

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.

ad7192_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 using the chip information.

Fixes: c3708c829a06 ("iio: adc: ad7192: Convert from of specific to fwnode property handling")
Cc: stable@vger.kernel.org
Signed-off-by: Jiale Yao <yaojiale02@163.com>
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iio/adc/ad7192.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
index 8b1664f6b102c..394137a127abb 100644
--- a/drivers/iio/adc/ad7192.c
+++ b/drivers/iio/adc/ad7192.c
@@ -1402,6 +1402,9 @@ static int ad7192_probe(struct spi_device *spi)
 	st->int_vref_mv = ret == -ENODEV ? avdd_mv : ret / MILLI;
 
 	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;
 	indio_dev->info = st->chip_info->info;
-- 
2.53.0