[PATCH 1/5] staging: media: tegra-video: add NULL checks for of_device_get_match_data()

[Alexandru Hossu]

tegra_csi_probe(), tegra_vi_probe(), and tegra_vip_probe() all call
of_device_get_match_data() to retrieve SoC-specific data from the device
tree match table, but none of them check the return value for NULL before
eventually dereferencing it.

In tegra_csi_probe(), the pointer is dereferenced on the very next
statement via csi->soc->num_clks. In tegra_vi_probe(), it is dereferenced
later via vi->soc->ops. In tegra_vip_probe(), vip->soc is stored and then
dereferenced at runtime via vip->soc->ops->vip_start_streaming(). A NULL
return would cause a kernel NULL pointer dereference in each case.

Add a NULL check returning -ENODEV in all three probe functions, consistent
with the defensive pattern already used in similar staging drivers such as
drivers/staging/media/sunxi/cedrus/cedrus_hw.c.

Signed-off-by: Alexandru Hossu <hossu.alexandru@xxxxxxxxx>
---
 drivers/staging/media/tegra-video/csi.c | 2 ++
 drivers/staging/media/tegra-video/vi.c  | 2 ++
 drivers/staging/media/tegra-video/vip.c | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/drivers/staging/media/tegra-video/csi.c b/drivers/staging/media/tegra-video/csi.c
index 7842104ca933..33369a8c803a 100644
--- a/drivers/staging/media/tegra-video/csi.c
+++ b/drivers/staging/media/tegra-video/csi.c
@@ -781,6 +781,8 @@ static int tegra_csi_probe(struct platform_device *pdev)
 		return PTR_ERR(csi->iomem);
 
 	csi->soc = of_device_get_match_data(&pdev->dev);
+	if (!csi->soc)
+		return -ENODEV;
 
 	csi->clks = devm_kcalloc(&pdev->dev, csi->soc->num_clks,
 				 sizeof(*csi->clks), GFP_KERNEL);
diff --git a/drivers/staging/media/tegra-video/vi.c b/drivers/staging/media/tegra-video/vi.c
index d1d934e361f7..f3b749f059f8 100644
--- a/drivers/staging/media/tegra-video/vi.c
+++ b/drivers/staging/media/tegra-video/vi.c
@@ -1907,6 +1907,8 @@ static int tegra_vi_probe(struct platform_device *pdev)
 		return PTR_ERR(vi->iomem);
 
 	vi->soc = of_device_get_match_data(&pdev->dev);
+	if (!vi->soc)
+		return -ENODEV;
 
 	vi->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(vi->clk)) {
diff --git a/drivers/staging/media/tegra-video/vip.c b/drivers/staging/media/tegra-video/vip.c
index 80cd3b113125..148c68ceb605 100644
--- a/drivers/staging/media/tegra-video/vip.c
+++ b/drivers/staging/media/tegra-video/vip.c
@@ -236,6 +236,8 @@ static int tegra_vip_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	vip->soc = of_device_get_match_data(&pdev->dev);
+	if (!vip->soc)
+		return -ENODEV;
 
 	vip->dev = &pdev->dev;
 	platform_set_drvdata(pdev, vip);
-- 
2.53.0