Re: [PATCH] iio: inv_mpu6050: Fully validate gyro and accel scale writes - Jean-Baptiste Maneyrol

From: Jean-Baptiste Maneyrol <JManeyrol@invensense.com>
To: Jonathan Cameron <jic23@kernel.org>,
	Lars-Peter Clausen <lars@metafoo.de>
Cc: "linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>
Subject: Re: [PATCH] iio: inv_mpu6050: Fully validate gyro and accel scale writes
Date: Tue, 6 Apr 2021 07:51:05 +0000	[thread overview]
Message-ID: <BL0PR12MB5011889BC549865552ECE88AC4769@BL0PR12MB5011.namprd12.prod.outlook.com> (raw)
In-Reply-To: <20210405155526.78ef4363@jic23-huawei>

Hi Jonathan, Lars-Peter,

thanks for letting me having a look. This is effectively as obvious as it looks.
Never think of testing that, thanks for the patch.

Acked-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>

Thanks,
JB

From: Jonathan Cameron <jic23@kernel.org>
Sent: Monday, April 5, 2021 16:55
To: Lars-Peter Clausen <lars@metafoo.de>
Cc: Jean-Baptiste Maneyrol <JManeyrol@invensense.com>; linux-iio@vger.kernel.org <linux-iio@vger.kernel.org>
Subject: Re: [PATCH] iio: inv_mpu6050: Fully validate gyro and accel scale writes 

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On Mon,  5 Apr 2021 13:44:41 +0200
Lars-Peter Clausen <lars@metafoo.de> wrote:

> When setting the gyro or accelerometer scale the inv_mpu6050 driver ignores
> the integer part of the value. As a result e.g. all of 0.13309, 1.13309,
> 12345.13309, ... are accepted as a valid gyro scale and 0.13309 is the
> scale that gets set in all those cases.
> 
> Make sure to check that the integer part of the scale value is 0 and reject
> it otherwise.
> 
> Fixes: 09a642b78523 ("Invensense MPU6050 Device Driver.")
> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Looks like this is in the 'obviously' correct category to me but
will leave it on list to give Jean-Baptiste a chance to look at it.

As ever, give me a poke if I seem to have lost it down the back of the
sofa in a few weeks time.

Thanks

Jonathan

> ---
>  drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 20 ++++++++++++++------
>  1 file changed, 14 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> index 453c51c79655..69ab94ab7297 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> @@ -731,12 +731,16 @@ inv_mpu6050_read_raw(struct iio_dev *indio_dev,
>        }
>  }
>  
> -static int inv_mpu6050_write_gyro_scale(struct inv_mpu6050_state *st, int val)
> +static int inv_mpu6050_write_gyro_scale(struct inv_mpu6050_state *st, int val,
> +                                     int val2)
>  {
>        int result, i;
>  
> +     if (val != 0)
> +             return -EINVAL;
> +
>        for (i = 0; i < ARRAY_SIZE(gyro_scale_6050); ++i) {
> -             if (gyro_scale_6050[i] == val) {
> +             if (gyro_scale_6050[i] == val2) {
>                        result = inv_mpu6050_set_gyro_fsr(st, i);
>                        if (result)
>                                return result;
> @@ -767,13 +771,17 @@ static int inv_write_raw_get_fmt(struct iio_dev *indio_dev,
>        return -EINVAL;
>  }
>  
> -static int inv_mpu6050_write_accel_scale(struct inv_mpu6050_state *st, int val)
> +static int inv_mpu6050_write_accel_scale(struct inv_mpu6050_state *st, int val,
> +                                      int val2)
>  {
>        int result, i;
>        u8 d;
>  
> +     if (val != 0)
> +             return -EINVAL;
> +
>        for (i = 0; i < ARRAY_SIZE(accel_scale); ++i) {
> -             if (accel_scale[i] == val) {
> +             if (accel_scale[i] == val2) {
>                        d = (i << INV_MPU6050_ACCL_CONFIG_FSR_SHIFT);
>                        result = regmap_write(st->map, st->reg->accl_config, d);
>                        if (result)
> @@ -814,10 +822,10 @@ static int inv_mpu6050_write_raw(struct iio_dev *indio_dev,
>        case IIO_CHAN_INFO_SCALE:
>                switch (chan->type) {
>                case IIO_ANGL_VEL:
> -                     result = inv_mpu6050_write_gyro_scale(st, val2);
> +                     result = inv_mpu6050_write_gyro_scale(st, val, val2);
>                        break;
>                case IIO_ACCEL:
> -                     result = inv_mpu6050_write_accel_scale(st, val2);
> +                     result = inv_mpu6050_write_accel_scale(st, val, val2);
>                        break;
>                default:
>                        result = -EINVAL;