Commit 623cf33c authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

ACPI / PM: Walk physical_node_list under physical_node_lock 



The list of physical devices corresponding to an ACPI device
object is walked by acpi_system_wakeup_device_seq_show() and
physical_device_enable_wakeup() without taking that object's
physical_node_lock mutex.  Since each of those functions may be
run at any time as a result of a user space action, the lack of
appropriate locking in them may lead to a kernel crash if that
happens during device hot-add or hot-remove involving the device
object in question.

Fix the issue by modifying acpi_system_wakeup_device_seq_show() and
physical_device_enable_wakeup() to use physical_node_lock as
appropriate.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: All <stable@vger.kernel.org>
parent b3b301c5

drivers/acpi/proc.c

+8 −0
Original line number Original line Diff line number Diff line
@@ -311,6 +311,8 @@ acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset) 
			   dev->pnp.bus_id,

			   dev->pnp.bus_id,

			   (u32) dev->wakeup.sleep_state);

			   (u32) dev->wakeup.sleep_state);





		mutex_lock(&dev->physical_node_lock);



		if (!dev->physical_node_count) {

		if (!dev->physical_node_count) {

			seq_printf(seq, "%c%-8s\n",

			seq_printf(seq, "%c%-8s\n",

				dev->wakeup.flags.run_wake ? '*' : ' ',

				dev->wakeup.flags.run_wake ? '*' : ' ',
@@ -338,6 +340,8 @@ acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset) 
				put_device(ldev);

				put_device(ldev);

			}

			}

		}

		}



		mutex_unlock(&dev->physical_node_lock);

	}

	}

	mutex_unlock(&acpi_device_lock);

	mutex_unlock(&acpi_device_lock);

	return 0;

	return 0;
@@ -347,12 +351,16 @@ static void physical_device_enable_wakeup(struct acpi_device *adev) 
{

{

	struct acpi_device_physical_node *entry;

	struct acpi_device_physical_node *entry;





	mutex_lock(&adev->physical_node_lock);



	list_for_each_entry(entry,

	list_for_each_entry(entry,

		&adev->physical_node_list, node)

		&adev->physical_node_list, node)

		if (entry->dev && device_can_wakeup(entry->dev)) {

		if (entry->dev && device_can_wakeup(entry->dev)) {

			bool enable = !device_may_wakeup(entry->dev);

			bool enable = !device_may_wakeup(entry->dev);

			device_set_wakeup_enable(entry->dev, enable);

			device_set_wakeup_enable(entry->dev, enable);

		}

		}



	mutex_unlock(&adev->physical_node_lock);

}

}





static ssize_t

static ssize_t

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