[PATCH] media: mediatek: vcodec: fix decoder child device leaks

[Guangshuo Li <lgs201920130244@gmail.com>]

mtk_vcodec_probe() populates decoder hardware child platform devices on
platforms that support decoder subdevices. These children must be
removed with of_platform_depopulate() when they are no longer needed.

If initialization fails after the children have been populated, the
probe error path releases the parent decoder resources without
depopulating the child devices. This leaves the child platform devices
registered.

The remove path has the same issue and leaves the child devices
registered when the parent decoder driver is unbound.

Depopulate the child devices in the probe error path and in the remove
path before tearing down the remaining parent resources.

The issue was identified by a static analysis tool I developed and
confirmed by manual review.

Fixes: c05bada35f01 ("media: mtk-vcodec: Add to support multi hardware decode")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 .../platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c    | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c
index e936ed8dffba..592685ad522c 100644
--- a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c
+++ b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c
@@ -517,6 +517,8 @@ static int mtk_vcodec_probe(struct platform_device *pdev)
 err_dec_mem_init:
 	video_unregister_device(vfd_dec);
 err_reg_cont:
+	if (dev->vdec_pdata->is_subdev_supported)
+		of_platform_depopulate(&pdev->dev);
 	if (dev->vdec_pdata->uses_stateless_api)
 		media_device_cleanup(&dev->mdev_dec);
 	destroy_workqueue(dev->decode_workqueue);
@@ -569,6 +571,9 @@ static void mtk_vcodec_dec_remove(struct platform_device *pdev)
 {
 	struct mtk_vcodec_dec_dev *dev = platform_get_drvdata(pdev);
 
+	if (dev->vdec_pdata->is_subdev_supported)
+		of_platform_depopulate(&pdev->dev);
+
 	destroy_workqueue(dev->decode_workqueue);
 
 	if (media_devnode_is_registered(dev->mdev_dec.devnode)) {
-- 
2.43.0