# \[PATCH\] iio: adc: imx25-gcq: fix uninitialized variable usage

- From: Yizhuo \<hidden\>
- Date: 2019-09-30 21:15:02 
- List: linux-arm-kernel
- Page: https://ratatoskr.run/linux-arm-kernel/2019/09/5729863
- Thread: https://ratatoskr.run/linux-iio/2019/09/5729863/t.md

```text
In function mx25_gcq_irq(), local variable "stats" could
be uninitialized if function regmap_read() returns -EINVAL.
However, this value is used in if statement, which is
potentially unsafe. The same case applied to the variable
"data" in function mx25_gcq_get_raw_value() in the same file.

Signed-off-by: Yizhuo <redacted>
---
 drivers/iio/adc/fsl-imx25-gcq.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/fsl-imx25-gcq.c b/drivers/iio/adc/fsl-imx25-gcq.c
index fa71489195c6..3b1e12b7c1ac 100644
--- a/drivers/iio/adc/fsl-imx25-gcq.c
+++ b/drivers/iio/adc/fsl-imx25-gcq.c
@@ -73,8 +73,12 @@ static irqreturn_t mx25_gcq_irq(int irq, void *data)
 {
 	struct mx25_gcq_priv *priv = data;
 	u32 stats;
+	int ret;
 
-	regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
+	ret = regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
+	if (ret) {
+		return ret;
+	}
 
 	if (stats & MX25_ADCQ_SR_EOQ) {
 		regmap_update_bits(priv->regs, MX25_ADCQ_MR,
@@ -100,6 +104,7 @@ static int mx25_gcq_get_raw_value(struct device *dev,
 {
 	long timeout;
 	u32 data;
+	int ret;
 
 	/* Setup the configuration we want to use */
 	regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0,
@@ -121,7 +126,11 @@ static int mx25_gcq_get_raw_value(struct device *dev,
 		return -ETIMEDOUT;
 	}
 
-	regmap_read(priv->regs, MX25_ADCQ_FIFO, &data);
+	ret = regmap_read(priv->regs, MX25_ADCQ_FIFO, &data);
+	if (ret) {
+		dev_err(dev, "Failed to read MX25_ADCQ_FIFO.\n");
+		return ret;
+	}
 
 	*val = MX25_ADCQ_FIFO_DATA(data);
 
-- 
2.17.1


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```