[PATCH 4.14 11/92] PCI: exynos: Fix a potential init_clk_resources NULL pointer dereference

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>

commit b5d6bc90c9129279d363ccbc02ad11e7b657c0b4 upstream.

In order to avoid triggering a NULL pointer dereference in
exynos_pcie_probe() a check must be put in place to detect if
the init_clk_resources hook is initialized before calling it.

Add the respective function pointer check in exynos_pcie_probe().

Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
[lorenzo.pieralisi@xxxxxxx: rewrote the commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/pci/dwc/pci-exynos.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/pci/dwc/pci-exynos.c
+++ b/drivers/pci/dwc/pci-exynos.c
@@ -695,7 +695,8 @@ static int __init exynos_pcie_probe(stru
 			return ret;
 	}
 
-	if (ep->ops && ep->ops->get_clk_resources) {
+	if (ep->ops && ep->ops->get_clk_resources &&
+			ep->ops->init_clk_resources) {
 		ret = ep->ops->get_clk_resources(ep);
 		if (ret)
 			return ret;