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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-11-14 23:18:32 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-11-14 23:18:32 +0100
commita104b4d467d1c4a09727bac2816928aef3304d3a (patch)
treeef1e2b2b10825be4c49c0ff2689a292835cd8dd4 /drivers/acpi/glue.c
parent3a83f992490f8235661b768e53bd5f14915420ac (diff)
downloadblackbird-op-linux-a104b4d467d1c4a09727bac2816928aef3304d3a.tar.gz
blackbird-op-linux-a104b4d467d1c4a09727bac2816928aef3304d3a.zip
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>
Diffstat (limited to 'drivers/acpi/glue.c')
-rw-r--r--drivers/acpi/glue.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index 782071fd3df3..a22a295edb69 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;
}
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