iio: dac: ad5770r: Put fwnode in error case during ->probe()

BugLink: https://bugs.launchpad.net/bugs/1931896
commit 98b7b0ca0828907dbb706387c11356a45463e2ea upstream.

device_for_each_child_node() bumps a reference counting of a returned variable.
We have to balance it whenever we return to the caller.

Fixes: cbbb819837f6 ("iio: dac: ad5770r: Add AD5770R support")
Cc: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210510095649.3302835-1-andy.shevchenko@gmail.com
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: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

diff --git a/drivers/iio/dac/ad5770r.c b/drivers/iio/dac/ad5770r.c
index 84dcf149261f96adbba236cbef6086a290ba7aaa..42decba1463cc0c801cc7df2db2959724f04b639 100644 (file)
--- a/drivers/iio/dac/ad5770r.c
+++ b/drivers/iio/dac/ad5770r.c
@@ -524,23 +524,29 @@ static int ad5770r_channel_config(struct ad5770r_state *st)
        device_for_each_child_node(&st->spi->dev, child) {
                ret = fwnode_property_read_u32(child, "num", &num);
                if (ret)
-                       return ret;
-               if (num >= AD5770R_MAX_CHANNELS)
-                       return -EINVAL;
+                       goto err_child_out;
+               if (num >= AD5770R_MAX_CHANNELS) {
+                       ret = -EINVAL;
+                       goto err_child_out;
+               }
 
                ret = fwnode_property_read_u32_array(child,
                                                     "adi,range-microamp",
                                                     tmp, 2);
                if (ret)
-                       return ret;
+                       goto err_child_out;
 
                min = tmp[0] / 1000;
                max = tmp[1] / 1000;
                ret = ad5770r_store_output_range(st, min, max, num);
                if (ret)
-                       return ret;
+                       goto err_child_out;
        }
 
+       return 0;
+
+err_child_out:
+       fwnode_handle_put(child);
        return ret;
 }