[PATCH 3.16 061/306] powerpc/eeh: Null check uses of eeh_pe_bus_get

Ben Hutchings
2017-02-15T23:27:55Z

From: Russell Currey <ruscur@russell.cc>

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>
---
arch/powerpc/kernel/eeh_driver.c | 8 ++++++++
arch/powerpc/platforms/powernv/eeh-ioda.c | 5 +++++
2 files changed, 13 insertions(+)

--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -828,6 +828,14 @@ static void eeh_handle_special_event(voi

/* 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);
--- 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
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);