PCI: Prevent NULL dereference during pciehp probe

pciehp assumes that dev->subordinate exists.  But we do not assign a bus if
we run out of bus numbers during enumeration.  This leads to a NULL
dereference in init_slot() (and other places).

Change pciehp_probe() to return -ENODEV when no subordinate bus is present.

Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index a2297db..07aa722 100644 (file)
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -255,6 +255,13 @@ static int pciehp_probe(struct pcie_device *dev)
        else if (pciehp_acpi_slot_detection_check(dev->port))
                goto err_out_none;
 
+       if (!dev->port->subordinate) {
+               /* Can happen if we run out of bus numbers during probe */
+               dev_err(&dev->device,
+                       "Hotplug bridge without secondary bus, ignoring\n");
+               goto err_out_none;
+       }
+
        ctrl = pcie_init(dev);
        if (!ctrl) {
                dev_err(&dev->device, "Controller initialization failed\n");