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From: Yongzhi Liu <lyz_cs@pku.edu.cn>
To: agross@kernel.org, bjorn.andersson@linaro.org, jic23@kernel.org,
	lars@metafoo.de
Cc: linux-arm-msm@vger.kernel.org, linux-iio@vger.kernel.org,
	linux-kernel@vger.kernel.org, fuyq@stu.pku.edu.cn,
	Yongzhi Liu <lyz_cs@pku.edu.cn>
Subject: [PATCH v2] iio: vadc: Fix potential dereference of NULL pointer
Date: Wed, 18 May 2022 22:50:55 -0700	[thread overview]
Message-ID: <1652939455-123139-1-git-send-email-lyz_cs@pku.edu.cn> (raw)
In-Reply-To: <YoUtezVzsPB8MAEO@google.com>

The return value of vadc_get_channel() needs to be checked
to avoid use of NULL pointer. Fix this by adding the null
pointer check on prop.

Fixes: 0917de94c ("iio: vadc: Qualcomm SPMI PMIC voltage ADC driver")

Signed-off-by: Yongzhi Liu <lyz_cs@pku.edu.cn>
---
 drivers/iio/adc/qcom-spmi-vadc.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c
index 34202ba..9fa61fb 100644
--- a/drivers/iio/adc/qcom-spmi-vadc.c
+++ b/drivers/iio/adc/qcom-spmi-vadc.c
@@ -358,14 +358,25 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc)
 	vadc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV;
 
 	prop = vadc_get_channel(vadc, VADC_REF_1250MV);
+	if (!prop) {
+		dev_err(vadc->dev, "Please define 1.25V channel\n");
+		ret = -ENODEV;
+		goto err;
+	}
 	ret = vadc_do_conversion(vadc, prop, &read_1);
 	if (ret)
 		goto err;
 
 	/* Try with buffered 625mV channel first */
 	prop = vadc_get_channel(vadc, VADC_SPARE1);
-	if (!prop)
+	if (!prop) {
 		prop = vadc_get_channel(vadc, VADC_REF_625MV);
+		if (!prop) {
+			dev_err(vadc->dev, "Please define 0.625V channel\n");
+			ret = -ENODEV;
+			goto err;
+		}
+	}
 
 	ret = vadc_do_conversion(vadc, prop, &read_2);
 	if (ret)
@@ -381,11 +392,21 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc)
 
 	/* Ratiometric calibration */
 	prop = vadc_get_channel(vadc, VADC_VDD_VADC);
+	if (!prop) {
+		dev_err(vadc->dev, "Please define VDD channel\n");
+		ret = -ENODEV;
+		goto err;
+	}
 	ret = vadc_do_conversion(vadc, prop, &read_1);
 	if (ret)
 		goto err;
 
 	prop = vadc_get_channel(vadc, VADC_GND_REF);
+	if (!prop) {
+		dev_err(vadc->dev, "Please define GND channel\n");
+		ret = -ENODEV;
+		goto err;
+	}
 	ret = vadc_do_conversion(vadc, prop, &read_2);
 	if (ret)
 		goto err;
-- 
2.7.4


  reply	other threads:[~2022-05-19  5:51 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-18  6:43 [PATCH] iio: vadc: Fix potential dereference of NULL pointer Yongzhi Liu
2022-05-18 17:31 ` Matthias Kaehlcke
2022-05-19  5:50   ` Yongzhi Liu [this message]
2022-05-20 17:13     ` [PATCH v2] " Jonathan Cameron
2022-05-21  3:31       ` [PATCH] hv_netvsc: " Yongzhi Liu
2022-05-21  3:34         ` 刘永志
2022-05-23 15:21         ` Andy Shevchenko
2022-05-23 15:45           ` 刘永志
2022-05-21  3:35       ` [PATCH v3] iio: vadc: " Yongzhi Liu
2022-05-22 11:01         ` Jonathan Cameron
2022-05-22 16:53           ` [PATCH v4] " Yongzhi Liu
2022-06-03 15:02             ` Jonathan Cameron
2022-06-03 15:20               ` Jonathan Cameron
2022-05-19 10:54 [PATCH v2] " Yongzhi Liu
2022-05-19 15:30 ` Kalle Valo
2022-05-19 16:35   ` 刘永志

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