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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] iio: vadc: Fix potential dereference of NULL pointer
Date:   Tue, 17 May 2022 23:43:00 -0700
Message-Id: <1652856180-100582-1-git-send-email-lyz_cs@pku.edu.cn>
Precedence: bulk

The return value of vadc_get_channel() needs to be checked
to avoid use of NULL pointer, which is followed by
the caller 'vadc_do_conversion' of function 'vadc_configure'.
Fix this by adding the null pointer check on prop
in function 'vadc_configure'.

Signed-off-by: Yongzhi Liu <lyz_cs@pku.edu.cn>
---
 drivers/iio/adc/qcom-spmi-vadc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c
index 34202ba..d99bd72 100644
--- a/drivers/iio/adc/qcom-spmi-vadc.c
+++ b/drivers/iio/adc/qcom-spmi-vadc.c
@@ -210,6 +210,9 @@ static int vadc_configure(struct vadc_priv *vadc,
 	u8 decimation, mode_ctrl;
 	int ret;
 
+	if (!prop)
+		return -ENODEV;
+
 	/* Mode selection */
 	mode_ctrl = (VADC_OP_MODE_NORMAL << VADC_OP_MODE_SHIFT) |
 		     VADC_ADC_TRIM_EN | VADC_AMUX_TRIM_EN;
-- 
2.7.4