diff options
| author | Vasileios Amoiridis <vassilisamir@gmail.com> | 2024-06-06 23:22:55 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-07-05 09:00:33 +0200 |
| commit | 6fa31bbe2ea8665ee970258eb8320cbf231dbe9e (patch) | |
| tree | dc723c566357116bd1f6f0cf6db5d43f48f6ea04 | |
| parent | d17f26afde5039c30297e9c6ffc273689e595154 (diff) | |
iio: chemical: bme680: Fix overflows in compensate() functions
commit fdd478c3ae98c3f13628e110dce9b6cfb0d9b3c8 upstream.
There are cases in the compensate functions of the driver that
there could be overflows of variables due to bit shifting ops.
These implications were initially discussed here [1] and they
were mentioned in log message of Commit 1b3bd8592780 ("iio:
chemical: Add support for Bosch BME680 sensor").
[1]: https://lore.kernel.org/linux-iio/20180728114028.3c1bbe81@archlinux/
Fixes: 1b3bd8592780 ("iio: chemical: Add support for Bosch BME680 sensor")
Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Link: https://lore.kernel.org/r/20240606212313.207550-4-vassilisamir@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/iio/chemical/bme680_core.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/iio/chemical/bme680_core.c b/drivers/iio/chemical/bme680_core.c index 08fb2f8a04d5..4b0487e5d2fc 100644 --- a/drivers/iio/chemical/bme680_core.c +++ b/drivers/iio/chemical/bme680_core.c @@ -348,10 +348,10 @@ static s16 bme680_compensate_temp(struct bme680_data *data, if (!calib->par_t2) bme680_read_calib(data, calib); - var1 = (adc_temp >> 3) - (calib->par_t1 << 1); + var1 = (adc_temp >> 3) - ((s32)calib->par_t1 << 1); var2 = (var1 * calib->par_t2) >> 11; var3 = ((var1 >> 1) * (var1 >> 1)) >> 12; - var3 = (var3 * (calib->par_t3 << 4)) >> 14; + var3 = (var3 * ((s32)calib->par_t3 << 4)) >> 14; data->t_fine = var2 + var3; calc_temp = (data->t_fine * 5 + 128) >> 8; @@ -374,9 +374,9 @@ static u32 bme680_compensate_press(struct bme680_data *data, var1 = (data->t_fine >> 1) - 64000; var2 = ((((var1 >> 2) * (var1 >> 2)) >> 11) * calib->par_p6) >> 2; var2 = var2 + (var1 * calib->par_p5 << 1); - var2 = (var2 >> 2) + (calib->par_p4 << 16); + var2 = (var2 >> 2) + ((s32)calib->par_p4 << 16); var1 = (((((var1 >> 2) * (var1 >> 2)) >> 13) * - (calib->par_p3 << 5)) >> 3) + + ((s32)calib->par_p3 << 5)) >> 3) + ((calib->par_p2 * var1) >> 1); var1 = var1 >> 18; var1 = ((32768 + var1) * calib->par_p1) >> 15; @@ -394,7 +394,7 @@ static u32 bme680_compensate_press(struct bme680_data *data, var3 = ((press_comp >> 8) * (press_comp >> 8) * (press_comp >> 8) * calib->par_p10) >> 17; - press_comp += (var1 + var2 + var3 + (calib->par_p7 << 7)) >> 4; + press_comp += (var1 + var2 + var3 + ((s32)calib->par_p7 << 7)) >> 4; return press_comp; } @@ -420,7 +420,7 @@ static u32 bme680_compensate_humid(struct bme680_data *data, (((temp_scaled * ((temp_scaled * calib->par_h5) / 100)) >> 6) / 100) + (1 << 14))) >> 10; var3 = var1 * var2; - var4 = calib->par_h6 << 7; + var4 = (s32)calib->par_h6 << 7; var4 = (var4 + ((temp_scaled * calib->par_h7) / 100)) >> 4; var5 = ((var3 >> 14) * (var3 >> 14)) >> 10; var6 = (var4 * var5) >> 1; |