powerpc/eeh: Null check uses of eeh_pe_bus_get

commit 04fec21c06e35b169a83e75a84a015ab4606bf5e upstream.

eeh_pe_bus_get() can return NULL if a PCI bus isn't found for a given PE.
Some callers don't check this, and can cause a null pointer dereference
under certain circumstances.

Fix this by checking NULL everywhere eeh_pe_bus_get() is called.

Fixes: 8a6b1bc70dbb ("powerpc/eeh: EEH core to handle special event")
Signed-off-by: Russell Currey <ruscur@russell.cc>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
index 420da61d4ce001d74ba64b675f8615b65f6e812a..5e4025c20c2d79db925f4c1f16474a9734f5e56e 100644 (file)
--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -828,6 +828,14 @@ static void eeh_handle_special_event(void)
 
                                /* Notify all devices to be down */
                                bus = eeh_pe_bus_get(phb_pe);
+                               if (!bus) {
+                                       pr_err("%s: Cannot find PCI bus for "
+                                              "PHB#%d-PE#%x\n",
+                                              __func__,
+                                              pe->phb->global_number,
+                                              pe->addr);
+                                       break;
+                               }
                                eeh_pe_dev_traverse(pe,
                                        eeh_report_failure, NULL);
                                pcibios_remove_pci_devices(bus);

diff --git a/arch/powerpc/platforms/powernv/eeh-ioda.c b/arch/powerpc/platforms/powernv/eeh-ioda.c
index 8ad0c5b891f4e3083e3b554b980f0eae54a51ab7..491e511f63e31a466131bfecbff8e514a47bc28f 100644 (file)
--- a/arch/powerpc/platforms/powernv/eeh-ioda.c
+++ b/arch/powerpc/platforms/powernv/eeh-ioda.c
@@ -578,6 +578,11 @@ static int ioda_eeh_reset(struct eeh_pe *pe, int option)
                ret = ioda_eeh_phb_reset(hose, option);
        } else {
                bus = eeh_pe_bus_get(pe);
+               if (!bus) {
+                       pr_err("%s: Cannot find PCI bus for PHB#%d-PE#%x\n",
+                              __func__, pe->phb->global_number, pe->addr);
+                       return -EIO;
+               }
                if (pci_is_root_bus(bus) ||
                    pci_is_root_bus(bus->parent))
                        ret = ioda_eeh_root_reset(hose, option);