[PATCH AUTOSEL 4.19 06/33] PCI: tegra: Fix OF node reference leak

Sasha Levin
2019-09-29T17:34:47Z

From: Nishka Dasgupta <nishkadg.linux@gmail.com>

[ Upstream commit 9e38e690ace3e7a22a81fc02652fc101efb340cf ]

Each iteration of for_each_child_of_node() executes of_node_put() on the
previous node, but in some return paths in the middle of the loop
of_node_put() is missing thus causing a reference leak.

Hence stash these mid-loop return values in a variable 'err' and add a
new label err_node_put which executes of_node_put() on the previous node
and returns 'err' on failure.

Change mid-loop return statements to point to jump to this label to
fix the reference leak.

Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
[lorenzo.pieralisi@arm.com: rewrote commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 f4f53d092e005..976eaa9a9f266 100644
--- a/drivers/pci/controller/pci-tegra.c
+++ b/drivers/pci/controller/pci-tegra.c
@@ -1975,14 +1975,15 @@ 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--;
@@ -1991,12 +1992,13 @@ 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);
@@ -2010,13 +2012,15 @@ 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);
@@ -2043,6 +2047,10 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
return err;

return 0;
+
+err_node_put:
+ of_node_put(port);
+ return err;
}

/*
--
2.20.1