aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-08-06 02:26:22 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-08-14 22:59:07 -0700
commitb97f921b94b1e70d5de999fd820ccf8504dc6528 (patch)
tree66c405bdc3086d5519c2d16ce07a65016d2967f2
parentda712f3a8c493986b19fd0863b45607c34061ba6 (diff)
downloadvexpress-lsk-b97f921b94b1e70d5de999fd820ccf8504dc6528.tar.gz
ACPI / PM: Walk physical_node_list under physical_node_lock
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/acpi/proc.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/acpi/proc.c b/drivers/acpi/proc.c
index aa1227a7e3f..04a13784dd2 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