Re: media: i2c: add OV02A10 image sensor driver

[Andy Shevchenko]

On Thu, Dec 3, 2020 at 8:03 PM Colin Ian King <colin.king@xxxxxxxxxxxxx> wrote:

> Static analysis on linux-next with Coverity has detected an issue with
> the following commit:

If you want to fix it properly, see my comments below...

> 529 static int ov02a10_s_stream(struct v4l2_subdev *sd, int on)
> 530 {
> 531        struct ov02a10 *ov02a10 = to_ov02a10(sd);
> 532        struct i2c_client *client =
> v4l2_get_subdevdata(&ov02a10->subdev);
>
>    1. var_decl: Declaring variable ret without initializer.
>
> 533        int ret;
> 534
> 535        mutex_lock(&ov02a10->mutex);
> 536
>
>    2. Condition ov02a10->streaming == on, taking true branch.
>
> 537        if (ov02a10->streaming == on)
>
>    3. Jumping to label unlock_and_return.
>
> 538                goto unlock_and_return;
> 539
> 540        if (on) {
> 541                ret = pm_runtime_get_sync(&client->dev);
> 542                if (ret < 0) {

> 543                        pm_runtime_put_noidle(&client->dev);
> 544                        goto unlock_and_return;

Instead of two above:
                       goto err_rpm_put;

> 545                }
> 546
> 547                ret = __ov02a10_start_stream(ov02a10);
> 548                if (ret) {
> 549                        __ov02a10_stop_stream(ov02a10);
> 550                        ov02a10->streaming = !on;
> 551                        goto err_rpm_put;
> 552                }
> 553        } else {
> 554                __ov02a10_stop_stream(ov02a10);
> 555                pm_runtime_put(&client->dev);
> 556        }
> 557
> 558        ov02a10->streaming = on;

(1)

> 559        mutex_unlock(&ov02a10->mutex);
> 560
> 561        return 0;
> 562
> 563 err_rpm_put:
> 564        pm_runtime_put(&client->dev);

> 565 unlock_and_return:

Should be moved to (1).

> 566        mutex_unlock(&ov02a10->mutex);
> 567
>
> Uninitialized scalar variable (UNINIT)
>     4. uninit_use: Using uninitialized value ret.
>
> 568        return ret;
> 569 }
>
> Variable ret has not been initialized, so the error return value is a
> garbage value. It should be initialized with some appropriate negative
> error code, or ret could be removed and the return should return a
> literal value of a error code.
>
> I was unsure what value is appropriate to fix this, so instead I'm
> reporting this issue.

-- 
With Best Regards,
Andy Shevchenko