Unfortunately, contrib/jsonb_plpython still contain a lot of problems in error
handling that can lead to memory leaks:
- not all Python function calls are checked for the success
- not in all places PG exceptions are caught to release Python references
But it seems that this errors can happen only in OOM case.
Attached patch with the fix. Back-patch for PG11 is needed.
--
Nikita Glukhov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
>From e40a9012c38c3b66888791d3dd3943adf9f310c8 Mon Sep 17 00:00:00 2001
From: Nikita Glukhov <n.glu...@postgrespro.ru>
Date: Tue, 15 Jan 2019 02:14:06 +0300
Subject: [PATCH] Fix memleaks and error handling in jsonb_plpython
---
contrib/jsonb_plpython/jsonb_plpython.c | 146 ++++++++++++++++++++++----------
1 file changed, 100 insertions(+), 46 deletions(-)
diff --git a/contrib/jsonb_plpython/jsonb_plpython.c b/contrib/jsonb_plpython/jsonb_plpython.c
index f44d364..3143b73 100644
--- a/contrib/jsonb_plpython/jsonb_plpython.c
+++ b/contrib/jsonb_plpython/jsonb_plpython.c
@@ -169,53 +169,80 @@ PLyObject_FromJsonbContainer(JsonbContainer *jsonb)
if (!result)
return NULL;
- while ((r = JsonbIteratorNext(&it, &v, true)) != WJB_DONE)
+ PG_TRY();
{
- if (r == WJB_ELEM)
+ while ((r = JsonbIteratorNext(&it, &v, true)) != WJB_DONE)
{
- PyObject *elem = PLyObject_FromJsonbValue(&v);
+ if (r == WJB_ELEM)
+ {
+ PyObject *elem = PLyObject_FromJsonbValue(&v);
+
+ if (!elem || PyList_Append(result, elem))
+ {
+ Py_XDECREF(elem);
+ Py_DECREF(result);
+ return NULL;
+ }
- PyList_Append(result, elem);
- Py_XDECREF(elem);
+ Py_DECREF(elem);
+ }
}
}
+ PG_CATCH();
+ {
+ Py_DECREF(result);
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
}
break;
case WJB_BEGIN_OBJECT:
- result = PyDict_New();
- if (!result)
- return NULL;
-
- while ((r = JsonbIteratorNext(&it, &v, true)) != WJB_DONE)
{
- if (r == WJB_KEY)
- {
- PyObject *key = PLyString_FromJsonbValue(&v);
-
- if (!key)
- return NULL;
+ PyObject *volatile key = NULL;
- r = JsonbIteratorNext(&it, &v, true);
+ result = PyDict_New();
+ if (!result)
+ return NULL;
- if (r == WJB_VALUE)
+ PG_TRY();
+ {
+ while ((r = JsonbIteratorNext(&it, &v, true)) != WJB_DONE)
{
- PyObject *value = PLyObject_FromJsonbValue(&v);
+ JsonbValue v2;
+ PyObject *val = NULL;
+
+ if (r != WJB_KEY)
+ continue;
+
+ if ((r = JsonbIteratorNext(&it, &v2, true)) != WJB_VALUE)
+ elog(ERROR, "unexpected jsonb token: %d", r);
- if (!value)
+ if (!(key = PLyString_FromJsonbValue(&v)) ||
+ !(val = PLyObject_FromJsonbValue(&v2)) ||
+ PyDict_SetItem(result, key, val))
{
Py_XDECREF(key);
+ Py_XDECREF(val);
+ Py_DECREF(result);
return NULL;
}
- PyDict_SetItem(result, key, value);
- Py_XDECREF(value);
+ Py_DECREF(val);
+ Py_DECREF(key);
+ key = NULL;
}
-
+ }
+ PG_CATCH();
+ {
Py_XDECREF(key);
+ Py_DECREF(result);
+ PG_RE_THROW();
}
+ PG_END_TRY();
+
+ break;
}
- break;
default:
elog(ERROR, "unexpected jsonb token: %d", r);
@@ -233,30 +260,40 @@ PLyObject_FromJsonbContainer(JsonbContainer *jsonb)
static JsonbValue *
PLyMapping_ToJsonbValue(PyObject *obj, JsonbParseState **jsonb_state)
{
- Py_ssize_t pcount;
- JsonbValue *out = NULL;
+ JsonbValue *out;
+ PyObject *items;
+ Py_ssize_t pcount = PyMapping_Size(obj);
+
+ if (pcount < 0)
+ PLy_elog(ERROR, "PyMapping_Size() failed, while converting mapping into jsonb");
- /* We need it volatile, since we use it after longjmp */
- volatile PyObject *items_v = NULL;
+ items = PyMapping_Items(obj);
- pcount = PyMapping_Size(obj);
- items_v = PyMapping_Items(obj);
+ if (!items)
+ PLy_elog(ERROR, "PyMapping_Items() failed, while converting mapping into jsonb");
PG_TRY();
{
Py_ssize_t i;
- PyObject *items;
-
- items = (PyObject *) items_v;
pushJsonbValue(jsonb_state, WJB_BEGIN_OBJECT, NULL);
for (i = 0; i < pcount; i++)
{
JsonbValue jbvKey;
- PyObject *item = PyList_GetItem(items, i);
- PyObject *key = PyTuple_GetItem(item, 0);
- PyObject *value = PyTuple_GetItem(item, 1);
+ PyObject *item;
+ PyObject *key;
+ PyObject *value;
+
+ item = PyList_GetItem(items, i); /* borrowed reference */
+ if (!item)
+ PLy_elog(ERROR, "PyList_GetItem() failed, while converting mapping into jsonb");
+
+ key = PyTuple_GetItem(item, 0); /* borrowed references */
+ value = PyTuple_GetItem(item, 1);
+
+ if (!key || !value)
+ PLy_elog(ERROR, "PyTuple_GetItem() failed, while converting mapping into jsonb");
/* Python dictionary can have None as key */
if (key == Py_None)
@@ -279,11 +316,13 @@ PLyMapping_ToJsonbValue(PyObject *obj, JsonbParseState **jsonb_state)
}
PG_CATCH();
{
- Py_DECREF(items_v);
+ Py_DECREF(items);
PG_RE_THROW();
}
PG_END_TRY();
+ Py_DECREF(items);
+
return out;
}
@@ -296,21 +335,36 @@ PLyMapping_ToJsonbValue(PyObject *obj, JsonbParseState **jsonb_state)
static JsonbValue *
PLySequence_ToJsonbValue(PyObject *obj, JsonbParseState **jsonb_state)
{
- Py_ssize_t i;
- Py_ssize_t pcount;
+ PyObject *seq = PySequence_Fast(obj, "object is not a sequence");
- pcount = PySequence_Size(obj);
+ if (!seq)
+ PLy_elog(ERROR, "PySequence_Fast() failed, while converting sequence into jsonb");
- pushJsonbValue(jsonb_state, WJB_BEGIN_ARRAY, NULL);
-
- for (i = 0; i < pcount; i++)
+ PG_TRY();
{
- PyObject *value = PySequence_GetItem(obj, i);
+ Py_ssize_t i;
+ Py_ssize_t pcount = PySequence_Fast_GET_SIZE(seq);
- (void) PLyObject_ToJsonbValue(value, jsonb_state, true);
+ pushJsonbValue(jsonb_state, WJB_BEGIN_ARRAY, NULL);
- Py_XDECREF(value);
+ for (i = 0; i < pcount; i++)
+ {
+ PyObject *value = PySequence_Fast_GET_ITEM(seq, i); /* borrowed reference */
+
+ if (!value)
+ PLy_elog(ERROR, "PySequence_Fast_GET_ITEM() failed, while converting sequence into jsonb");
+
+ (void) PLyObject_ToJsonbValue(value, jsonb_state, true);
+ }
}
+ PG_CATCH();
+ {
+ Py_DECREF(seq);
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
+
+ Py_DECREF(seq);
return pushJsonbValue(jsonb_state, WJB_END_ARRAY, NULL);
}
--
2.7.4
