[PATCH] iio: adc: Fix potential integer overflow

From: Gustavo A. R. Silva
Date: Tue Sep 18 2018 - 09:14:40 EST


Cast factor to s64 in order to give the compiler complete information
about the proper arithmetic to use and avoid a potential integer
overflow. Notice that such variable is being used in a context
that expects an expression of type s64 (64 bits, signed).

Addresses-Coverity-ID: 1324146 ("Unintentional integer overflow")
Fixes: e13d757279bb ("iio: adc: Add QCOM SPMI PMIC5 ADC driver")
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
drivers/iio/adc/qcom-vadc-common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/adc/qcom-vadc-common.c b/drivers/iio/adc/qcom-vadc-common.c
index dcd7fb5..e360e27 100644
--- a/drivers/iio/adc/qcom-vadc-common.c
+++ b/drivers/iio/adc/qcom-vadc-common.c
@@ -282,7 +282,7 @@ static int qcom_vadc_scale_code_voltage_factor(u16 adc_code,
voltage = div64_s64(voltage, data->full_scale_code_volt);
if (voltage > 0) {
voltage *= prescale->den;
- temp = prescale->num * factor;
+ temp = prescale->num * (s64)factor;
voltage = div64_s64(voltage, temp);
} else {
voltage = 0;
--
2.7.4