| From | Kamal Mostafa <> | Subject | [PATCH 099/133] ACPI / PM: Walk physical_node_list under physical_node_lock | Date | Fri, 16 Aug 2013 15:34:01 -0700 |
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3.8.13.7 -stable review patch. If anyone has any objections, please let me know.
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From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
commit 623cf33cb055b1e81fa47e4fc16789b2c129e31e upstream.
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> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/acpi/proc.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/acpi/proc.c b/drivers/acpi/proc.c index 52ce767..8fa2d08 100644 --- a/drivers/acpi/proc.c +++ b/drivers/acpi/proc.c @@ -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 -- 1.8.1.2
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