iio_scan_mask_match() returns NULL if the passed in scan mask is empty. This will happen if no channel has been selected and buffer is enabled. iio_sw_buffer_preenable() will assign NULL to indio_dev->active_scan_mask in this case and as a result iio_update_demux() will cause a NULL pointer deref, because it expects active_scan_mask to be non-NULL. Since it does not make much sense to start data capture if there is no data to capture this patch updates the code to fail gracefully in iio_scan_mask_match() instead of crashing the kernel. Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx> --- drivers/iio/industrialio-buffer.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index ac185b8..2f35db9 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -553,6 +553,10 @@ int iio_sw_buffer_preenable(struct iio_dev *indio_dev) buffer->scan_mask); else indio_dev->active_scan_mask = buffer->scan_mask; + + if (indio_dev->active_scan_mask == NULL) + return -EINVAL; + iio_update_demux(indio_dev); if (indio_dev->info->update_scan_mode) -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
