[PATCH] drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform device

[Haojie Li]

platform_device_register_data() can fail and return an ERR_PTR, but the
return value is used without checking, leading to an invalid pointer
being stored in ddp_comp[].dev and passed to component_match_add() and
mtk_ddp_comp_init(), which could result in a kernel crash.

Add an IS_ERR() check to jump to the error handling path on failure.

Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195")
Cc: stable at vger.kernel.org
Signed-off-by: Haojie Li <lihaojie at kylinos.cn>
---
 drivers/gpu/drm/mediatek/mtk_drm_drv.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index c86a3f54f35b..667d7fdbfbac 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -1112,6 +1112,10 @@ static int mtk_drm_probe(struct platform_device *pdev)
 							    PLATFORM_DEVID_AUTO,
 							    (void *)private->mmsys_dev,
 							    sizeof(*private->mmsys_dev));
+		if (IS_ERR(ovl_adaptor)) {
+			ret = PTR_ERR(ovl_adaptor);
+			goto err_node;
+		}
 		private->ddp_comp[DDP_COMPONENT_DRM_OVL_ADAPTOR].dev = &ovl_adaptor->dev;
 		mtk_ddp_comp_init(dev, NULL, &private->ddp_comp[DDP_COMPONENT_DRM_OVL_ADAPTOR],
 				  DDP_COMPONENT_DRM_OVL_ADAPTOR);
-- 
2.25.1