[POWERPC] Fix possible NULL deref in ppc32 PCI

The 32-bit PCI code tests if "bus" is non-NULL after calling
pci_scan_bus_parented() in one place but not another before
dereferencing it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/pci_32.c b/arch/powerpc/kernel/pci_32.c
index 37cb7b944319..a9c6cb24aab0 100644
--- a/arch/powerpc/kernel/pci_32.c
+++ b/arch/powerpc/kernel/pci_32.c
@@ -442,9 +442,10 @@ static int __init pcibios_init(void)
                 hose->last_busno = 0xff;
                 bus = pci_scan_bus_parented(hose->parent, hose->first_busno,
                                             hose->ops, hose);
-                if (bus)
+                if (bus) {
                         pci_bus_add_devices(bus);
-                hose->last_busno = bus->subordinate;
+                        hose->last_busno = bus->subordinate;
+                }
                 if (pci_assign_all_buses || next_busno <= hose->last_busno)
                         next_busno = hose->last_busno + pcibios_assign_bus_offset;
         }