From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
According to the changelog of commit 29ed1f29b68a (PCI: pciehp: Fix null
pointer deref when hot-removing SR-IOV device) it is unsafe to walk the
bus->devices list of a PCI bus and remove devices from it in direct order,
because that may lead to NULL pointer dereferences related to virtual
functions.
For this reason, change all of the bus->devices list walks in
acpiphp_glue.c during which devices may be removed to be carried out in
reverse order.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Tested-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
drivers/pci/hotplug/acpiphp_glue.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
Index: linux-pm/drivers/pci/hotplug/acpiphp_glue.c
===================================================================
--- linux-pm.orig/drivers/pci/hotplug/acpiphp_glue.c
+++ linux-pm/drivers/pci/hotplug/acpiphp_glue.c
@@ -742,7 +742,7 @@ static void trim_stale_devices(struct pc
/* The device is a bridge. so check the bus below it. */
pm_runtime_get_sync(&dev->dev);
- list_for_each_entry_safe(child, tmp, &bus->devices, bus_list)
+ list_for_each_entry_safe_reverse(child, tmp, &bus->devices, bus_list)
trim_stale_devices(child);
pm_runtime_put(&dev->dev);
@@ -773,8 +773,8 @@ static void acpiphp_check_bridge(struct
; /* do nothing */
} else if (get_slot_status(slot) == ACPI_STA_ALL) {
/* remove stale devices if any */
- list_for_each_entry_safe(dev, tmp, &bus->devices,
- bus_list)
+ list_for_each_entry_safe_reverse(dev, tmp,
+ &bus->devices, bus_list)
if (PCI_SLOT(dev->devfn) == slot->device)
trim_stale_devices(dev);
@@ -805,7 +805,7 @@ static void acpiphp_sanitize_bus(struct
int i;
unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM;
- list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) {
+ list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
for (i=0; i<PCI_BRIDGE_RESOURCES; i++) {
struct resource *res = &dev->resource[i];
if ((res->flags & type_mask) && !res->start &&
--
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