staging:iio:dac:ad5686: Check for negative values

Currently it is possible to write negative values to the ad5686's raw attribute.
This will cause undefined behaviour, so reject negative values.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/iio/dac/ad5686.c b/drivers/staging/iio/dac/ad5686.c
index 1d50dd1..48389e1 100644 (file)
--- a/drivers/staging/iio/dac/ad5686.c
+++ b/drivers/staging/iio/dac/ad5686.c
@@ -327,7 +327,7 @@ static int ad5686_write_raw(struct iio_dev *indio_dev,
 
        switch (mask) {
        case 0:
-               if (val > (1 << chan->scan_type.realbits))
+               if (val > (1 << chan->scan_type.realbits) || val < 0)
                        return -EINVAL;
 
                mutex_lock(&indio_dev->mlock);