iio: dln2: Check return value of devm_iio_trigger_register()

BugLink: https://bugs.launchpad.net/bugs/1954931
commit 90751fb9f224e0e1555b49a8aa9e68f6537e4cec upstream.

Registering a trigger can fail and the return value of
devm_iio_trigger_register() must be checked. Otherwise undefined behavior
can occur when the trigger is used.

Fixes: 7c0299e879dd ("iio: adc: Add support for DLN2 ADC")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211101133043.6974-1-lars@metafoo.de
Cc: <stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/iio/adc/dln2-adc.c b/drivers/iio/adc/dln2-adc.c
index 6c67192946aadf892208bf4ef6e9e5adaf528791..97d162a3cba4eaaec1442718898d539698529951 100644 (file)
--- a/drivers/iio/adc/dln2-adc.c
+++ b/drivers/iio/adc/dln2-adc.c
@@ -655,7 +655,11 @@ static int dln2_adc_probe(struct platform_device *pdev)
                return -ENOMEM;
        }
        iio_trigger_set_drvdata(dln2->trig, dln2);
-       devm_iio_trigger_register(dev, dln2->trig);
+       ret = devm_iio_trigger_register(dev, dln2->trig);
+       if (ret) {
+               dev_err(dev, "failed to register trigger: %d\n", ret);
+               return ret;
+       }
        iio_trigger_set_immutable(indio_dev, dln2->trig);
 
        ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,