[PATCH 4.14 115/167] PCI: keystone: Fix interrupt-controller-node lookup

Greg Kroah-Hartman
2018-02-21T12:48:46Z

From: Johan Hovold <johan@kernel.org>

commit eac56aa3bc8af3d9b9850345d0f2da9d83529134 upstream.

Fix child-node lookup during initialisation which was using the wrong
OF-helper and ended up searching the whole device tree depth-first
starting at the parent rather than just matching on its children.

To make things worse, the parent pci node could end up being prematurely
freed as of_find_node_by_name() drops a reference to its first argument.
Any matching child interrupt-controller node was also leaked.

Fixes: 0c4ffcfe1fbc ("PCI: keystone: Add TI Keystone PCIe driver")
Cc: stable <stable@vger.kernel.org> # 3.18
Acked-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
[lorenzo.pieralisi@arm.com: updated commit subject]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/pci/dwc/pci-keystone.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/pci/dwc/pci-keystone.c
+++ b/drivers/pci/dwc/pci-keystone.c
@@ -178,7 +178,7 @@ static int ks_pcie_get_irq_controller_in
}

/* interrupt controller is in a child node */
- *np_temp = of_find_node_by_name(np_pcie, controller);
+ *np_temp = of_get_child_by_name(np_pcie, controller);
if (!(*np_temp)) {
dev_err(dev, "Node for %s is absent\n", controller);
return -EINVAL;
@@ -187,6 +187,7 @@ static int ks_pcie_get_irq_controller_in
temp = of_irq_count(*np_temp);
if (!temp) {
dev_err(dev, "No IRQ entries in %s\n", controller);
+ of_node_put(*np_temp);
return -EINVAL;
}

@@ -204,6 +205,8 @@ static int ks_pcie_get_irq_controller_in
break;
}

+ of_node_put(*np_temp);
+
if (temp) {
*num_irqs = temp;
return 0;