diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-11-14 23:18:32 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-11-14 23:18:32 +0100 |
| commit | a104b4d467d1c4a09727bac2816928aef3304d3a (patch) | |
| tree | ef1e2b2b10825be4c49c0ff2689a292835cd8dd4 | |
| parent | 3a83f992490f8235661b768e53bd5f14915420ac (diff) | |
ACPI / bind: Use (put|get)_device() on ACPI device objects too
When associating a "physical" device with an ACPI device object
acpi_bind_one() only uses get_device() to increment the reference
counter of the former, but there is no reason not to do that with
the latter too. Among other things, that may help to avoid
use-after-free when an ACPI device object is freed without calling
acpi_unbind_one() for all "physical" devices associated with it
(that only can happen in buggy code, but then it's better if the
kernel doesn't crash as a result of a bug).
For this reason, modify acpi_bind_one() to apply get_device() to
the ACPI device object too and update acpi_unbind_one() to drop
that reference using put_device() as appropriate.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Lan Tianyu <tianyu.lan@intel.com>
| -rw-r--r-- | drivers/acpi/glue.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c index 782071fd3df..a22a295edb6 100644 --- a/drivers/acpi/glue.c +++ b/drivers/acpi/glue.c @@ -217,6 +217,7 @@ int acpi_bind_one(struct device *dev, acpi_handle handle) if (!acpi_dev) return -EINVAL; + get_device(&acpi_dev->dev); get_device(dev); physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL); if (!physical_node) { @@ -243,6 +244,7 @@ int acpi_bind_one(struct device *dev, acpi_handle handle) goto err; put_device(dev); + put_device(&acpi_dev->dev); return 0; } if (pn->node_id == node_id) { @@ -282,6 +284,7 @@ int acpi_bind_one(struct device *dev, acpi_handle handle) err: ACPI_COMPANION_SET(dev, NULL); put_device(dev); + put_device(&acpi_dev->dev); return retval; } EXPORT_SYMBOL_GPL(acpi_bind_one); @@ -307,8 +310,9 @@ int acpi_unbind_one(struct device *dev) sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name); sysfs_remove_link(&dev->kobj, "firmware_node"); ACPI_COMPANION_SET(dev, NULL); - /* acpi_bind_one() increase refcnt by one. */ + /* Drop references taken by acpi_bind_one(). */ put_device(dev); + put_device(&acpi_dev->dev); kfree(entry); break; } |