media: mtk-mdp: Fix error handling in probe function

[ Upstream commit 8a8a323 ]

Add mtk_mdp_unregister_m2m_device() on the error handling path to prevent
resource leak.

Add check for the return value of vpu_get_plat_device() to prevent null
pointer dereference. And vpu_get_plat_device() increases the reference
count of the returned platform device. Add platform_device_put() to
prevent reference leak.

Fixes: c8eb2d7 ("[media] media: Add Mediatek MDP Driver")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Haoxiang Li

drivers/media/platform/mediatek/mdp/mtk_mdp_core.c

@@ -194,26 +194,38 @@ static int mtk_mdp_probe(struct platform_device *pdev)
 	}
 
 	mdp->vpu_dev = vpu_get_plat_device(pdev);
+	if (!mdp->vpu_dev) {
+		dev_err(&pdev->dev, "Failed to get vpu device\n");
+		ret = -ENODEV;
+		goto err_vpu_get_dev;
+	}
+
 	ret = vpu_wdt_reg_handler(mdp->vpu_dev, mtk_mdp_reset_handler, mdp,
 				  VPU_RST_MDP);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to register reset handler\n");
-		goto err_m2m_register;
+		goto err_reg_handler;
 	}
 
 	platform_set_drvdata(pdev, mdp);
 
 	ret = vb2_dma_contig_set_max_seg_size(&pdev->dev, DMA_BIT_MASK(32));
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to set vb2 dma mag seg size\n");
-		goto err_m2m_register;
+		goto err_reg_handler;
 	}
 
 	pm_runtime_enable(dev);
 	dev_dbg(dev, "mdp-%d registered successfully\n", mdp->id);
 
 	return 0;
 
+err_reg_handler:
+	platform_device_put(mdp->vpu_dev);
+
+err_vpu_get_dev:
+	mtk_mdp_unregister_m2m_device(mdp);
+
 err_m2m_register:
 	v4l2_device_unregister(&mdp->v4l2_dev);