[PATCH] drm/vc4: Fix firmware reference leak in vc4_hvs_bind()

[PATCH] drm/vc4: Fix firmware reference leak in vc4_hvs_bind()

[Wentao Liang]

The firmware reference taken via rpi_firmware_get() is leaked when
either of the devm_clk_get() calls for the core or display clocks
fails, as both error paths return without releasing it.

Put the firmware reference before returning from both clock lookup
error paths.

Fixes: 2a001ca00ad5 ("drm/vc4: hdmi: Rework hdmi_enable_4kp60 detection code")
Cc: stable@vger.kernel.org
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 drivers/gpu/drm/vc4/vc4_hvs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index ee8d0738501b..20dde4150068 100644
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -1680,6 +1680,7 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
 					     (vc4->gen >= VC4_GEN_6_C) ? "core" : NULL);
 		if (IS_ERR(hvs->core_clk)) {
 			dev_err(&pdev->dev, "Couldn't get core clock\n");
+			rpi_firmware_put(firmware);
 			return PTR_ERR(hvs->core_clk);
 		}
 
@@ -1687,6 +1688,7 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
 					     (vc4->gen >= VC4_GEN_6_C) ? "disp" : NULL);
 		if (IS_ERR(hvs->disp_clk)) {
 			dev_err(&pdev->dev, "Couldn't get disp clock\n");
+			rpi_firmware_put(firmware);
 			return PTR_ERR(hvs->disp_clk);
 		}
 
-- 
2.34.1

Re: [PATCH] drm/vc4: Fix firmware reference leak in vc4_hvs_bind()

[Maíra Canal]

Hi Wentao,

On 16/09/26 12:41, Wentao Liang wrote:
> The firmware reference taken via rpi_firmware_get() is leaked when
> either of the devm_clk_get() calls for the core or display clocks
> fails, as both error paths return without releasing it.
> 
> Put the firmware reference before returning from both clock lookup
> error paths.
> 
> Fixes: 2a001ca00ad5 ("drm/vc4: hdmi: Rework hdmi_enable_4kp60 detection code")
> Cc: stable@vger.kernel.org
> Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
> ---
>   drivers/gpu/drm/vc4/vc4_hvs.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
> index ee8d0738501b..20dde4150068 100644
> --- a/drivers/gpu/drm/vc4/vc4_hvs.c
> +++ b/drivers/gpu/drm/vc4/vc4_hvs.c
> @@ -1680,6 +1680,7 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
>   					     (vc4->gen >= VC4_GEN_6_C) ? "core" : NULL);
>   		if (IS_ERR(hvs->core_clk)) {
>   			dev_err(&pdev->dev, "Couldn't get core clock\n");
> +			rpi_firmware_put(firmware);

Instead of adding this line twice, move the line `firmware =
rpi_firmware_get(node)` closer to its actual use. Then, you don't need
to add these `rpi_firmware_put()` calls.

The same comment applies to your other PATCH: `[PATCH] drm/vc4: Fix
firmware reference leak in vc4_drm_bind()`.

Best regards,
- Maíra

>   			return PTR_ERR(hvs->core_clk);
>   		}
>   
> @@ -1687,6 +1688,7 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
>   					     (vc4->gen >= VC4_GEN_6_C) ? "disp" : NULL);
>   		if (IS_ERR(hvs->disp_clk)) {
>   			dev_err(&pdev->dev, "Couldn't get disp clock\n");
> +			rpi_firmware_put(firmware);
>   			return PTR_ERR(hvs->disp_clk);
>   		}
>