[PATCH] PCI: tegra: Add of_node_put() before return to fix reference leak

[Nishka Dasgupta <nishkadg.linux@xxxxxxxxx>]

Each iteration of for_each_child_of_node() puts the previous node, but
in the case of a return from the middle of the loop, there is no put,
thus causing a reference leak.

Hence store these mid-loop return values in variable err and add a new
label err_node_put which puts the previous node and returns err. Change
six mid-loop return statements to point to this new label instead.

Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@xxxxxxxxx>
---
Changes in v2: 
- Edit subject line to better reflect changes and match other patches on
  this driver.
- Edit commit message for readability and accuracy.

 drivers/pci/controller/pci-tegra.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
index 9a917b2456f6..673a1725ef38 100644
--- a/drivers/pci/controller/pci-tegra.c
+++ b/drivers/pci/controller/pci-tegra.c
@@ -2237,14 +2237,15 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
 		err = of_pci_get_devfn(port);
 		if (err < 0) {
 			dev_err(dev, "failed to parse address: %d\n", err);
-			return err;
+			goto err_node_put;
 		}
 
 		index = PCI_SLOT(err);
 
 		if (index < 1 || index > soc->num_ports) {
 			dev_err(dev, "invalid port number: %d\n", index);
-			return -EINVAL;
+			err = -EINVAL;
+			goto err_node_put;
 		}
 
 		index--;
@@ -2253,12 +2254,13 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
 		if (err < 0) {
 			dev_err(dev, "failed to parse # of lanes: %d\n",
 				err);
-			return err;
+			goto err_node_put;
 		}
 
 		if (value > 16) {
 			dev_err(dev, "invalid # of lanes: %u\n", value);
-			return -EINVAL;
+			err = -EINVAL;
+			goto err_node_put;
 		}
 
 		lanes |= value << (index << 3);
@@ -2272,13 +2274,15 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
 		lane += value;
 
 		rp = devm_kzalloc(dev, sizeof(*rp), GFP_KERNEL);
-		if (!rp)
-			return -ENOMEM;
+		if (!rp) {
+			err = -ENOMEM;
+			goto err_node_put;
+		}
 
 		err = of_address_to_resource(port, 0, &rp->regs);
 		if (err < 0) {
 			dev_err(dev, "failed to parse address: %d\n", err);
-			return err;
+			goto err_node_put;
 		}
 
 		INIT_LIST_HEAD(&rp->list);
@@ -2330,6 +2334,10 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
 		return err;
 
 	return 0;
+
+err_node_put:
+	of_node_put(port);
+	return err;
 }
 
 /*
-- 
2.19.1