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ACPI / PM: Walk physical_node_list under physical_node_lock

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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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: All <stable@vger.kernel.org>
This commit is contained in:
Rafael J. Wysocki 2013-08-06 02:26:22 +02:00
parent b3b301c5fe
commit 623cf33cb0
1 changed files with 8 additions and 0 deletions
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8
drivers/acpi/proc.c
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@ -311,6 +311,8 @@ acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset)
dev->pnp.bus_id,
(u32) dev->wakeup.sleep_state);
mutex_lock(&dev->physical_node_lock);
if (!dev->physical_node_count) {
seq_printf(seq, "%c%-8s\n",
dev->wakeup.flags.run_wake ? '*' : ' ',
@ -338,6 +340,8 @@ acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset)
put_device(ldev);
}
}
mutex_unlock(&dev->physical_node_lock);
}
mutex_unlock(&acpi_device_lock);
return 0;
@ -347,12 +351,16 @@ static void physical_device_enable_wakeup(struct acpi_device *adev)
{
struct acpi_device_physical_node *entry;
mutex_lock(&adev->physical_node_lock);
list_for_each_entry(entry,
&adev->physical_node_list, node)
if (entry->dev && device_can_wakeup(entry->dev)) {
bool enable = !device_may_wakeup(entry->dev);
device_set_wakeup_enable(entry->dev, enable);
}
mutex_unlock(&adev->physical_node_lock);
}
static ssize_t