[PATCH 6.1.y] media: platform: mtk-mdp3: fix NULL deref on failed SCP lookup

[Sasha Levin <sashal@kernel.org>]

From: Johan Hovold <johan@kernel.org>

[ Upstream commit 90368323fb244da0504e3da37a182f8e89bcc3b9 ]

Add the missing sanity check after looking up the SCP to avoid
dereferencing a NULL-pointer in case its driver has not yet been bound.

Fixes: 61890ccaefaf ("media: platform: mtk-mdp3: add MediaTek MDP3 driver")
Cc: stable@vger.kernel.org	# 6.1
Cc: Moudy Ho <moudy.ho@mediatek.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
[ Adapted NULL-check placement to the older direct platform_get_drvdata() lookup. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/platform/mediatek/mdp3/mtk-mdp3-core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-core.c b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-core.c
index 97edcd9d1c817..9a11064ecfa95 100644
--- a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-core.c
+++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-core.c
@@ -241,6 +241,11 @@ static int mdp_probe(struct platform_device *pdev)
 		goto err_destroy_clock_wq;
 	}
 	mdp->scp = platform_get_drvdata(mm_pdev);
+	if (!mdp->scp) {
+		ret = -EPROBE_DEFER;
+		goto err_destroy_clock_wq;
+	}
+
 	mdp->rproc_handle = scp_get_rproc(mdp->scp);
 	dev_dbg(&pdev->dev, "MDP rproc_handle: %pK", mdp->rproc_handle);
 
-- 
2.53.0