Patch "PCI: pciehp: Fix null pointer deref when hot-removing SR-IOV device" has been added to the 3.10-stable tree

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

    PCI: pciehp: Fix null pointer deref when hot-removing SR-IOV device

to the 3.10-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:
     pci-pciehp-fix-null-pointer-deref-when-hot-removing-sr-iov-device.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From 29ed1f29b68a8395d5679b3c4e38352b617b3236 Mon Sep 17 00:00:00 2001
From: Yinghai Lu <yinghai@xxxxxxxxxx>
Date: Fri, 19 Jul 2013 12:14:16 -0700
Subject: PCI: pciehp: Fix null pointer deref when hot-removing SR-IOV device

From: Yinghai Lu <yinghai@xxxxxxxxxx>

commit 29ed1f29b68a8395d5679b3c4e38352b617b3236 upstream.

Hot-removing a device with SR-IOV enabled causes a null pointer dereference
in v3.9 and v3.10.

This is a regression caused by ba518e3c17 ("PCI: pciehp: Iterate over all
devices in slot, not functions 0-7").  When we iterate over the
bus->devices list, we first remove the PF, which also removes all the VFs
from the list.  Then the list iterator blows up because more than just the
current entry was removed from the list.

ac205b7bb7 ("PCI: make sriov work with hotplug remove") works around a
similar problem in pci_stop_bus_devices() by iterating over the list in
reverse, so the VFs are stopped and removed from the list first, before the
PF.

This patch changes pciehp_unconfigure_device() to iterate over the list in
reverse, too.

[bhelgaas: bugzilla, changelog]
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=60604
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Acked-by: Yijing Wang <wangyijing@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/pci/hotplug/pciehp_pci.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

--- a/drivers/pci/hotplug/pciehp_pci.c
+++ b/drivers/pci/hotplug/pciehp_pci.c
@@ -92,7 +92,14 @@ int pciehp_unconfigure_device(struct slo
 	if (ret)
 		presence = 0;
 
-	list_for_each_entry_safe(dev, temp, &parent->devices, bus_list) {
+	/*
+	 * Stopping an SR-IOV PF device removes all the associated VFs,
+	 * which will update the bus->devices list and confuse the
+	 * iterator.  Therefore, iterate in reverse so we remove the VFs
+	 * first, then the PF.  We do the same in pci_stop_bus_device().
+	 */
+	list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
+					 bus_list) {
 		pci_dev_get(dev);
 		if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE && presence) {
 			pci_read_config_byte(dev, PCI_BRIDGE_CONTROL, &bctl);


Patches currently in stable-queue which might be from yinghai@xxxxxxxxxx are

queue-3.10/pci-pciehp-fix-null-pointer-deref-when-hot-removing-sr-iov-device.patch
queue-3.10/pci-retry-allocation-of-only-the-resource-type-that-failed.patch
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