Re: [PATCH v4] media: atomisp: fix the uninitialized use and rename "retvalue"

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Aug 11, 2021 at 10:54:17PM -0700, Yizhuo Zhai wrote:
> Inside function mt9m114_detect(), variable "retvalue" could
> be uninitialized if mt9m114_read_reg() returns error, however, it
> is used in the later if statement, which is potentially unsafe.
> 
> The local variable "retvalue" is renamed to "model" to avoid
> confusion.
> 
> Fixes: ad85094b293e ("Revert "media: staging: atomisp: Remove driver"")
> Signed-off-by: Yizhuo Zhai<yzhai003@ucr.edu>
> ---
>  drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c b/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
> index f5de81132177..77293579a134 100644
> --- a/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
> +++ b/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
> @@ -1533,16 +1533,19 @@ static struct v4l2_ctrl_config mt9m114_controls[] = {
>  static int mt9m114_detect(struct mt9m114_device *dev, struct i2c_client *client)
>  {
>  	struct i2c_adapter *adapter = client->adapter;
> -	u32 retvalue;
> +	u32 model;
> +	int ret;
>  
>  	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
>  		dev_err(&client->dev, "%s: i2c error", __func__);
>  		return -ENODEV;
>  	}
> -	mt9m114_read_reg(client, MISENSOR_16BIT, (u32)MT9M114_PID, &retvalue);
> -	dev->real_model_id = retvalue;
> +	ret = mt9m114_read_reg(client, MISENSOR_16BIT, MT9M114_PID, &model);
> +	if (ret)
> +		return ret;
> +	dev->real_model_id = model;
>  
> -	if (retvalue != MT9M114_MOD_ID) {
> +	if (model != MT9M114_MOD_ID) {
>  		dev_err(&client->dev, "%s: failed: client->addr = %x\n",
>  			__func__, client->addr);
>  		return -ENODEV;
> -- 
> 2.25.1
> 
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

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