2021-06-23 05:55:42

by Yizhuo Zhai

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

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.

Signed-off-by: Yizhuo <[email protected]>
---
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..fbd6c6cd84c8 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, (u32)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;
--
2.17.1

2021-06-23 07:57:50

by Sakari Ailus

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

Hi Yizhuo,

On Wed, Jun 23, 2021 at 05:56:31AM +0000, Yizhuo 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.
>
> Signed-off-by: Yizhuo <[email protected]>
> ---
> 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..fbd6c6cd84c8 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, (u32)MT9M114_PID, &model);

This is over 80 characters.

You can also drop the cast, which also reduces the line length.

> + 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;

--
Regards,

Sakari Ailus