acpi_pci_get_bridge_handle() returns the ACPI handle for the bridge device
(either a host bridge or a PCI-to-PCI bridge) leading to a PCI bus. But
SR-IOV virtual functions can be on a virtual bus with no bridge leading to
it. Return a NULL acpi_handle in this case instead of trying to
dereference the NULL pointer to the bridge.
This fixes a NULL pointer dereference oops in pci_get_hp_params() when
adding SR-IOV VF devices on virtual buses.
[bhelgaas: changelog, add comment in code]
Fixes: 6cd33649fa ("PCI: Add pci_configure_device() during enumeration")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=87591
Reported-by: Chao Zhou <chao.zhou@intel.com>
Reported-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
32f638fc11