On Wed, Aug 14, 2024, Krzysztof Kozlowski wrote:
> The probe function never performs any paltform device allocation, thus
> error path "undo_platform_dev_alloc" is entirely bogus. It drops the
> reference count from the platform device being probed. If error path is
> triggered, this will lead to unbalanced device reference counts and
> premature release of device resources, thus possible use-after-free when
> releasing remaining devm-managed resources.
>
> Fixes: f83fca0707c6 ("usb: dwc3: add ST dwc3 glue layer to manage dwc3 HC")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> ---
> drivers/usb/dwc3/dwc3-st.c | 11 +++--------
> 1 file changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/usb/dwc3/dwc3-st.c b/drivers/usb/dwc3/dwc3-st.c
> index 211360eee95a..a9cb04043f08 100644
> --- a/drivers/usb/dwc3/dwc3-st.c
> +++ b/drivers/usb/dwc3/dwc3-st.c
> @@ -219,10 +219,8 @@ static int st_dwc3_probe(struct platform_device *pdev)
> dwc3_data->regmap = regmap;
>
> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-reg");
> - if (!res) {
> - ret = -ENXIO;
> - goto undo_platform_dev_alloc;
> - }
> + if (!res)
> + return -ENXIO;
>
> dwc3_data->syscfg_reg_off = res->start;
>
> @@ -233,8 +231,7 @@ static int st_dwc3_probe(struct platform_device *pdev)
> devm_reset_control_get_exclusive(dev, "powerdown");
> if (IS_ERR(dwc3_data->rstc_pwrdn)) {
> dev_err(&pdev->dev, "could not get power controller\n");
> - ret = PTR_ERR(dwc3_data->rstc_pwrdn);
> - goto undo_platform_dev_alloc;
> + return PTR_ERR(dwc3_data->rstc_pwrdn);
> }
>
> /* Manage PowerDown */
> @@ -300,8 +297,6 @@ static int st_dwc3_probe(struct platform_device *pdev)
> reset_control_assert(dwc3_data->rstc_rst);
> undo_powerdown:
> reset_control_assert(dwc3_data->rstc_pwrdn);
> -undo_platform_dev_alloc:
> - platform_device_put(pdev);
> return ret;
> }
>
> --
> 2.43.0
>
Acked-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Thanks,
Thinh
