Re: [PATCH 4.14 04/33] Input: stmfts - fix reference leak in stmfts_input_open

Pavel Machek
2022-05-25T10:53:05Z

[-- Attachment #1: Type: text/plain, Size: 1680 bytes --]

Hi!

> From: Zheng Yongjun <zhengyongjun3@huawei.com>
>
> [ Upstream commit 26623eea0da3476446909af96c980768df07bbd9 ]
>
> pm_runtime_get_sync() will increment pm usage counter even it
> failed. Forgetting to call pm_runtime_put_noidle will result
> in reference leak in stmfts_input_open, so we should fix it.

This is wrong, AFAICT.

> drivers/input/touchscreen/stmfts.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/input/touchscreen/stmfts.c b/drivers/input/touchscreen/stmfts.c
> index d9e93dabbca2..9007027a7ad9 100644
> --- a/drivers/input/touchscreen/stmfts.c
> +++ b/drivers/input/touchscreen/stmfts.c
> @@ -344,11 +344,11 @@ static int stmfts_input_open(struct input_dev *dev)
>
> err = pm_runtime_get_sync(&sdata->client->dev);
> if (err < 0)
> - return err;
> + goto out;
>
> err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
> if (err)
> - return err;
> + goto out;
>
> mutex_lock(&sdata->mutex);
> sdata->running = true;
> @@ -371,7 +371,9 @@ static int stmfts_input_open(struct input_dev *dev)
> "failed to enable touchkey\n");
> }
>
> - return 0;
> +out:
> + pm_runtime_put_noidle(&sdata->client->dev);
> + return err;
> }
>
> static void stmfts_input_close(struct input_dev *dev)

We are now doing put even on the success path. That will break the
device... and will result in non-functional device and double put due
to the close path.

Best regards,
Pavel
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]