[PATCH 4.14 20/26] iommu/qcom: Fix local_base status check

[Greg Kroah-Hartman]

From: Tang Bin <tangbin@xxxxxxxxxxxxxxxxxxxx>

commit b52649aee6243ea661905bdc5fbe28cc5f6dec76 upstream.

The function qcom_iommu_device_probe() does not perform sufficient
error checking after executing devm_ioremap_resource(), which can
result in crashes if a critical error path is encountered.

Fixes: 0ae349a0f33f ("iommu/qcom: Add qcom_iommu")
Signed-off-by: Tang Bin <tangbin@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200418134703.1760-1-tangbin@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/iommu/qcom_iommu.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/iommu/qcom_iommu.c
+++ b/drivers/iommu/qcom_iommu.c
@@ -775,8 +775,11 @@ static int qcom_iommu_device_probe(struc
 	qcom_iommu->dev = dev;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (res)
+	if (res) {
 		qcom_iommu->local_base = devm_ioremap_resource(dev, res);
+		if (IS_ERR(qcom_iommu->local_base))
+			return PTR_ERR(qcom_iommu->local_base);
+	}
 
 	qcom_iommu->iface_clk = devm_clk_get(dev, "iface");
 	if (IS_ERR(qcom_iommu->iface_clk)) {