4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stefan Windfeldt-Prytz <stefan.windfeldt@xxxxxxxx> commit 4cd140bda6494543f1c1b0ccceceaa44b676eef6 upstream. If no iio buffer has been set up and poll is called return 0. Without this check there will be a null pointer dereference when calling poll on a iio driver without an iio buffer. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Stefan Windfeldt-Prytz <stefan.windfeldt@xxxxxxxx> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iio/industrialio-buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -174,7 +174,7 @@ unsigned int iio_buffer_poll(struct file struct iio_dev *indio_dev = filp->private_data; struct iio_buffer *rb = indio_dev->buffer; - if (!indio_dev->info) + if (!indio_dev->info || rb == NULL) return 0; poll_wait(filp, &rb->pollq, wait);