[Update,3/6] ACPI / hotplug: Fix handle_root_bridge_removal()
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Message ID 6808835.gmCqHn1NaE@vostro.rjw.lan
State New, archived
Headers show
Series
  • ACPI scan and hotplug fixes
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Commit Message

Rafael J. Wysocki Nov. 4, 2013, 1:33 p.m. UTC
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

It is required to do get_device() on the struct acpi_device in
question before passing it to acpi_bus_hot_remove_device() through
acpi_os_hotplug_execute(), because acpi_bus_hot_remove_device()
calls acpi_scan_hot_remove() that does put_device() on that
object.

The ACPI PCI root removal routine, handle_root_bridge_removal(),
doesn't do that, which may lead to premature freeing of the
device object or to executing put_device() on an object that
has been freed already.

Fix this problem by making handle_root_bridge_removal() use
get_device() as appropriate.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/pci_root.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)


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Comments

Toshi Kani Nov. 6, 2013, 11:21 p.m. UTC | #1
On Mon, 2013-11-04 at 14:33 +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> It is required to do get_device() on the struct acpi_device in
> question before passing it to acpi_bus_hot_remove_device() through
> acpi_os_hotplug_execute(), because acpi_bus_hot_remove_device()
> calls acpi_scan_hot_remove() that does put_device() on that
> object.
> 
> The ACPI PCI root removal routine, handle_root_bridge_removal(),
> doesn't do that, which may lead to premature freeing of the
> device object or to executing put_device() on an object that
> has been freed already.
> 
> Fix this problem by making handle_root_bridge_removal() use
> get_device() as appropriate.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Acked-by: Toshi Kani <toshi.kani@hp.com>

Thanks,
-Toshi

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Patch
diff mbox series

Index: linux-pm/drivers/acpi/pci_root.c
===================================================================
--- linux-pm.orig/drivers/acpi/pci_root.c
+++ linux-pm/drivers/acpi/pci_root.c
@@ -608,9 +608,12 @@  static void handle_root_bridge_removal(s
 	ej_event->device = device;
 	ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 
+	get_device(&device->dev);
 	status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
-	if (ACPI_FAILURE(status))
+	if (ACPI_FAILURE(status)) {
+		put_device(&device->dev);
 		kfree(ej_event);
+	}
 }
 
 static void _handle_hotplug_event_root(struct work_struct *work)