[PATCH] media: atomisp: fix the uninitialized use

[PATCH] media: atomisp: fix the uninitialized use

[Yizhuo Zhai]

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.

Signed-off-by: Yizhuo <yzhai003@ucr.edu>
---
 drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
b/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
index f5de81132177..8ddddb18ffbb 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
@@ -1534,12 +1534,15 @@ static int mt9m114_detect(struct
mt9m114_device *dev, struct i2c_client *client)
 {
        struct i2c_adapter *adapter = client->adapter;
        u32 retvalue;
+       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);
+       ret = mt9m114_read_reg(client, MISENSOR_16BIT,
(u32)MT9M114_PID, &retvalue);
+       if (ret)
+               return ret;
        dev->real_model_id = retvalue;

        if (retvalue != MT9M114_MOD_ID) {
-- 
2.17.1

Re: [PATCH] media: atomisp: fix the uninitialized use

[Hans Verkuil]

On 15/06/2021 20:45, 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.
> 
> Signed-off-by: Yizhuo <yzhai003@ucr.edu>
> ---
>  drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
> b/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
> index f5de81132177..8ddddb18ffbb 100644
> --- a/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
> +++ b/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
> @@ -1534,12 +1534,15 @@ static int mt9m114_detect(struct
> mt9m114_device *dev, struct i2c_client *client)
>  {
>         struct i2c_adapter *adapter = client->adapter;
>         u32 retvalue;
> +       int ret;

Hmm, 'ret' and 'retvalue'. That's a bit confusing. Just rename 'retvalue'
to 'model', then it makes more sense.

> 
>         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);
> +       ret = mt9m114_read_reg(client, MISENSOR_16BIT,
> (u32)MT9M114_PID, &retvalue);
> +       if (ret)
> +               return ret;
>         dev->real_model_id = retvalue;
> 
>         if (retvalue != MT9M114_MOD_ID) {
> 

This patch got mangled by your mail client: long lines were wrapped around.

Regards,

	Hans