diff options
| author | Doug Anderson <dianders@chromium.org> | 2014-02-13 14:39:34 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-22 12:41:27 -0800 |
| commit | 600b64afd789d3d0deaf467b5fd88bca8d459768 (patch) | |
| tree | bf85aa357aee31b0626877f277c203d75f70f1d0 | |
| parent | 5f32e4632c22a12b8ddc2e16c2be6b2988baf57a (diff) | |
hwmon: (ntc_thermistor) Avoid math overflow
commit d3d89c468ceebbcf9423d1a3d66c5bf91f569570 upstream.
The ntc thermistor code was doing math whose temporary result might
have overflowed 32-bits. We need some casts in there to make it safe.
In one example I found:
- pullup_uV: 1800000
- result of iio_read_channel_raw: 3226
- 1800000 * 3226 => 0x15a1cbc80
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/hwmon/ntc_thermistor.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/hwmon/ntc_thermistor.c b/drivers/hwmon/ntc_thermistor.c index d6d640a733d5..9297164a23a5 100644 --- a/drivers/hwmon/ntc_thermistor.c +++ b/drivers/hwmon/ntc_thermistor.c @@ -145,7 +145,7 @@ struct ntc_data { static int ntc_adc_iio_read(struct ntc_thermistor_platform_data *pdata) { struct iio_channel *channel = pdata->chan; - unsigned int result; + s64 result; int val, ret; ret = iio_read_channel_raw(channel, &val); @@ -155,10 +155,10 @@ static int ntc_adc_iio_read(struct ntc_thermistor_platform_data *pdata) } /* unit: mV */ - result = pdata->pullup_uv * val; + result = pdata->pullup_uv * (s64) val; result >>= 12; - return result; + return (int)result; } static const struct of_device_id ntc_match[] = { |