[PATCH] iommu/rockchip: check return value of of_find_device_by_node() in rk_iommu_of_xlate()

[Yu Kuai]

If of_find_device_by_node() failed in rk_iommu_of_xlate(), null pointer
dereference will be triggered. Thus return error code if
of_find_device_by_node() failed.

Fixes: 5fd577c3eac3("iommu/rockchip: Use OF_IOMMU to attach devices automatically")
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
 drivers/iommu/rockchip-iommu.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index e5d86b7177de..090d149ef8e9 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -1099,6 +1099,9 @@ static int rk_iommu_of_xlate(struct device *dev,
 
 	iommu_dev = of_find_device_by_node(args->np);
 
+	if (!iommu_dev)
+		return -ENODEV;
+
 	data->iommu = platform_get_drvdata(iommu_dev);
 	dev_iommu_priv_set(dev, data);
 
-- 
2.25.4