[PATCH v5] of: dynamic: fix memory leak related to properties of __of_node_dup

From: Lixin Wang
Date: Sun Oct 22 2017 - 23:21:29 EST


If a node with no properties is dynamically added, then a property is
dynamically added to the node, then the property is dynamically removed,
the result will be node->properties == NULL and node->deadprops != NULL.

Add a separate function to release the properties in both lists.

Signed-off-by: Lixin Wang <alan.1.wang@xxxxxxxxxxxxxxx>
---
v4 -> v5:
* fix the bug in v4, that the prop->next should be saved before release
the prop.

drivers/of/dynamic.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 301b6db..39d69d3 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -315,6 +315,18 @@ int of_detach_node(struct device_node *np)
}
EXPORT_SYMBOL_GPL(of_detach_node);

+static void property_list_free(struct property *prop_list)
+{
+ struct property *prop, *next;
+
+ for (prop = prop_list; prop != NULL; prop = next) {
+ next = prop->next;
+ kfree(prop->name);
+ kfree(prop->value);
+ kfree(prop);
+ }
+}
+
/**
* of_node_release() - release a dynamically allocated node
* @kref: kref element of the node to be released
@@ -324,7 +336,6 @@ EXPORT_SYMBOL_GPL(of_detach_node);
void of_node_release(struct kobject *kobj)
{
struct device_node *node = kobj_to_device_node(kobj);
- struct property *prop = node->properties;

/* We should never be releasing nodes that haven't been detached. */
if (!of_node_check_flag(node, OF_DETACHED)) {
@@ -335,18 +346,9 @@ void of_node_release(struct kobject *kobj)
if (!of_node_check_flag(node, OF_DYNAMIC))
return;

- while (prop) {
- struct property *next = prop->next;
- kfree(prop->name);
- kfree(prop->value);
- kfree(prop);
- prop = next;
+ property_list_free(node->properties);
+ property_list_free(node->deadprops);

- if (!prop) {
- prop = node->deadprops;
- node->deadprops = NULL;
- }
- }
kfree(node->full_name);
kfree(node->data);
kfree(node);
--
2.6.2