iio: adc: meson-saradc: check for devm_kasprintf failure

[ Upstream commit aad172b017617994343e36d8659c69e14cd694fd ]

devm_kasprintf() may return NULL on failure of internal allocation thus
the assignments to  init.name  are not safe if not checked. On error
meson_sar_adc_clk_init() returns negative values so -ENOMEM in the
(unlikely) failure case of devm_kasprintf() should be fine here.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Fixes: 3adbf3427330 ("iio: adc: add a driver for the SAR ADC found in Amlogic Meson SoCs")
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/iio/adc/meson_saradc.c

@@ -589,6 +589,9 @@ static int meson_sar_adc_clk_init(struct iio_dev *indio_dev,
 
 	init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%pOF#adc_div",
 				   indio_dev->dev.of_node);
+	if (!init.name)
+		return -ENOMEM;
+
 	init.flags = 0;
 	init.ops = &clk_divider_ops;
 	clk_parents[0] = __clk_get_name(priv->clkin);
@@ -608,6 +611,9 @@ static int meson_sar_adc_clk_init(struct iio_dev *indio_dev,
 
 	init.name = devm_kasprintf(&indio_dev->dev, GFP_KERNEL, "%pOF#adc_en",
 				   indio_dev->dev.of_node);
+	if (!init.name)
+		return -ENOMEM;
+
 	init.flags = CLK_SET_RATE_PARENT;
 	init.ops = &clk_gate_ops;
 	clk_parents[0] = __clk_get_name(priv->adc_div_clk);