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") Cc: stable@xxxxxxxxxxxxxxx # v3.11+ Signed-off-by: Russell Currey <ruscur@xxxxxxxxxx> Reviewed-by: Andrew Donnellan <andrew.donnellan@xxxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> --- this specific patch for 4.4 only --- arch/powerpc/kernel/eeh_driver.c | 8 ++++++++ arch/powerpc/platforms/powernv/eeh-powernv.c | 5 +++++ 2 files changed, 13 insertions(+) diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c index 247a0dc..c07bfb5 100644 --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -909,6 +909,14 @@ static void eeh_handle_special_event(void) /* Notify all devices to be down */ eeh_pe_state_clear(pe, EEH_PE_PRI_BUS); 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-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c index 2ba60259..4d822f4 100644 --- a/arch/powerpc/platforms/powernv/eeh-powernv.c +++ b/arch/powerpc/platforms/powernv/eeh-powernv.c @@ -956,6 +956,11 @@ static int pnv_eeh_reset(struct eeh_pe *pe, int option) } 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 = pnv_eeh_root_reset(hose, option); -- 2.10.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html