On Thu, Aug 10, 2017 at 06:23:34PM +0300, Anton Vasilyev wrote:
> If stts751 hw by some reason reports conversion rate bigger then 9:
>       ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_RATE);
> then dereference stts751_intervals[priv->interval] leads to buffer
> overread.
> 
> The path adds sanity check for value read from chip.
> 
> Found by Linux Driver Verification project (linuxtesting.org).
> 
> Signed-off-by: Anton Vasilyev <vasil...@ispras.ru>
> ---
>  drivers/hwmon/stts751.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/hwmon/stts751.c b/drivers/hwmon/stts751.c
> index d56251d..f6eddbd 100644
> --- a/drivers/hwmon/stts751.c
> +++ b/drivers/hwmon/stts751.c
> @@ -718,6 +718,10 @@ static int stts751_read_chip_config(struct stts751_priv 
> *priv)
>       ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_RATE);
>       if (ret < 0)
>               return ret;
> +     if (ret > ARRAY_SIZE(stts751_intervals)) {

Great catch, but should this be >= ?

Guenter

> +             dev_err(priv->dev, "Unrecognized conversion rate 0x%x\n", ret);
> +             return -ENODEV;
> +     }
>       priv->interval = ret;
>  
>       ret = stts751_read_reg16(priv, &priv->event_max,
> -- 
> 2.7.4
> 

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