In case the conversion has failed or returned zero, processing *val can lead to a division by zero. Need to check for errors, or converted value is zero, before processing the data. In case the converted value is zero, e.g. the Vrefint channel, this should be considered as invalid in all cases. Fixes: 0e346b2cfa85 ("iio: adc: stm32-adc: add vrefint calibration support") Reported-by: Sashiko Link: https://lore.kernel.org/all/20260911161555.244F31F000FF@smtp.kernel.org/ Cc: stable@vger.kernel.org Signed-off-by: Fabrice Gasnier --- Changes in v2: - Review comments from Andy: -- Correct commit message: single paragraph -- Use a temporary variable instead of *val to improve readability -- Drop ternary operation and use simpler conditional checks - Link to v1: https://patch.msgid.link/20260915-adc-fix-div0-v1-1-7daed9e52f2f@foss.st.com --- drivers/iio/adc/stm32-adc.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 5c6c06b269be..b9468b9e560a 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -1609,8 +1609,23 @@ static int stm32_adc_read_raw(struct iio_dev *indio_dev, else ret = -EINVAL; - if (mask == IIO_CHAN_INFO_PROCESSED) - *val = STM32_ADC_VREFINT_VOLTAGE * adc->vrefint.vrefint_cal / *val; + if (mask == IIO_CHAN_INFO_PROCESSED) { + int vrefint_raw; + + if (ret < 0) { + iio_device_release_direct(indio_dev); + return ret; + } + + vrefint_raw = *val; + + if (vrefint_raw == 0) { + iio_device_release_direct(indio_dev); + return -EINVAL; + } + + *val = STM32_ADC_VREFINT_VOLTAGE * adc->vrefint.vrefint_cal / vrefint_raw; + } iio_device_release_direct(indio_dev); return ret; --- base-commit: 8d3ae59288f1e7d58d76558a6ee96d533bc5019f change-id: 20260915-adc-fix-div0-ae38365abfeb Best regards, -- Fabrice Gasnier