Patch "powerpc/eeh: Null check uses of eeh_pe_bus_get" has been added to the 4.8-stable tree

This is a note to let you know that I've just added the patch titled

powerpc/eeh: Null check uses of eeh_pe_bus_get

to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
powerpc-eeh-null-check-uses-of-eeh_pe_bus_get.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Russell Currey <[email protected]>
Date: Mon, 12 Sep 2016 14:17:22 +1000
Subject: powerpc/eeh: Null check uses of eeh_pe_bus_get

From: Russell Currey <[email protected]>

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.

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

@@ -994,6 +994,14 @@ static void eeh_handle_special_event(voi
 				/* 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);
 				pci_hp_remove_devices(bus);

@@ -1091,6 +1091,11 @@ static int pnv_eeh_reset(struct eeh_pe *
 	}
 
 	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 (pe->type & EEH_PE_VF)
 		return pnv_eeh_reset_vf_pe(pe, option);
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.8/powerpc-powernv-pass-cpu-endian-pe-number-to-opal_pci_eeh_freeze_clear.patch queue-4.8/powerpc-powernv-use-cpu-endian-hub-diag-data-type-in-pnv_eeh_get_and_dump_hub_diag.patch queue-4.8/powerpc-eeh-null-check-uses-of-eeh_pe_bus_get.patch