From: Florian Forster <octo@collectd.org>
Date: Tue, 8 Dec 2015 12:41:35 +0000 (+0100)
Subject: python plugin: Fix memory leak.
X-Git-Tag: collectd-5.5.1~13^2~10
X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=3e413a72f2387d600fa00169823c7ce0d0b649b5;p=collectd.git

python plugin: Fix memory leak.

The regiser_read / register_write functions assume a user_data_t*
pointing to static memory and will not store / free the pointer.

CID: 38002
---

diff --git a/src/python.c b/src/python.c
index 95240afb..6a65ff25 100644
--- a/src/python.c
+++ b/src/python.c
@@ -573,7 +573,7 @@ static PyObject *cpy_register_generic_userdata(void *reg, void *handler, PyObjec
 	char buf[512];
 	reg_function_t *register_function = (reg_function_t *) reg;
 	cpy_callback_t *c = NULL;
-	user_data_t *user_data = NULL;
+	user_data_t user_data;
 	char *name = NULL;
 	PyObject *callback = NULL, *data = NULL;
 	static char *kwlist[] = {"callback", "data", "name", NULL};
@@ -594,17 +594,19 @@ static PyObject *cpy_register_generic_userdata(void *reg, void *handler, PyObjec
 	c->callback = callback;
 	c->data = data;
 	c->next = NULL;
-	user_data = malloc(sizeof(*user_data));
-	user_data->free_func = cpy_destroy_user_data;
-	user_data->data = c;
-	register_function(buf, handler, user_data);
+
+	memset (&user_data, 0, sizeof (user_data));
+	user_data.free_func = cpy_destroy_user_data;
+	user_data.data = c;
+
+	register_function(buf, handler, &user_data);
 	return cpy_string_to_unicode_or_bytes(buf);
 }
 
 static PyObject *cpy_register_read(PyObject *self, PyObject *args, PyObject *kwds) {
 	char buf[512];
 	cpy_callback_t *c = NULL;
-	user_data_t *user_data = NULL;
+	user_data_t user_data;
 	double interval = 0;
 	char *name = NULL;
 	PyObject *callback = NULL, *data = NULL;
@@ -627,13 +629,16 @@ static PyObject *cpy_register_read(PyObject *self, PyObject *args, PyObject *kwd
 	c->callback = callback;
 	c->data = data;
 	c->next = NULL;
-	user_data = malloc(sizeof(*user_data));
-	user_data->free_func = cpy_destroy_user_data;
-	user_data->data = c;
+
+	memset (&user_data, 0, sizeof (user_data));
+	user_data.free_func = cpy_destroy_user_data;
+	user_data.data = c;
+
 	ts.tv_sec = interval;
 	ts.tv_nsec = (interval - ts.tv_sec) * 1000000000;
-	plugin_register_complex_read(/* group = */ NULL, buf,
-			cpy_read_callback, &ts, user_data);
+	plugin_register_complex_read(/* group = */ "python", buf,
+			cpy_read_callback, &ts, &user_data);
+
 	return cpy_string_to_unicode_or_bytes(buf);
 }