PCI: mediatek: Add missing of_node_put() to fix reference leak

The for_each_available_child_of_node helper internally makes use of the
of_get_next_available_child() which performs an of_node_get() on each
iteration when searching for next available child node.

Should an available child node be found, then it would return a device
node pointer with reference count incremented, thus early return from
the middle of the loop requires an explicit of_node_put() to prevent
reference count leak.

To stop the reference leak, explicitly call of_node_put() before
returning after an error occurred.

Link: https://lore.kernel.org/r/20210120184810.3068794-1-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
index cf4c18f..23548b5 100644 (file)
--- a/drivers/pci/controller/pcie-mediatek.c
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -1035,14 +1035,14 @@ static int mtk_pcie_setup(struct mtk_pcie *pcie)
                err = of_pci_get_devfn(child);
                if (err < 0) {
                        dev_err(dev, "failed to parse devfn: %d\n", err);
-                       return err;
+                       goto error_put_node;
                }
 
                slot = PCI_SLOT(err);
 
                err = mtk_pcie_parse_port(pcie, child, slot);
                if (err)
-                       return err;
+                       goto error_put_node;
        }
 
        err = mtk_pcie_subsys_powerup(pcie);
@@ -1058,6 +1058,9 @@ static int mtk_pcie_setup(struct mtk_pcie *pcie)
                mtk_pcie_subsys_powerdown(pcie);
 
        return 0;
+error_put_node:
+       of_node_put(child);
+       return err;
 }
 
 static int mtk_pcie_probe(struct platform_device *pdev)