bpo-44304: Fix crash in the sqlite3 module when the GC clears Statement objects (GH-26545)
(cherry picked from commit fa106a685c1f199aca5be5c2d0277a14cc9057bd)
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
diff --git a/Lib/sqlite3/test/userfunctions.py b/Lib/sqlite3/test/userfunctions.py
index 6f57d19..4290890 100644
--- a/Lib/sqlite3/test/userfunctions.py
+++ b/Lib/sqlite3/test/userfunctions.py
@@ -23,6 +23,7 @@
import unittest
import unittest.mock
+import gc
import sqlite3 as sqlite
def func_returntext():
@@ -322,6 +323,22 @@ def test_func_deterministic_keyword_only(self):
with self.assertRaises(TypeError):
self.con.create_function("deterministic", 0, int, True)
+ def test_function_destructor_via_gc(self):
+ # See bpo-44304: The destructor of the user function can
+ # crash if is called without the GIL from the gc functions
+ dest = sqlite.connect(':memory:')
+ def md5sum(t):
+ return
+
+ dest.create_function("md5", 1, md5sum)
+ x = dest("create table lang (name, first_appeared)")
+ del md5sum, dest
+
+ y = [x]
+ y.append(y)
+
+ del x,y
+ gc.collect()
class AggregateTests(unittest.TestCase):
def setUp(self):
diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-06-05-02-34-57.bpo-44304._MAoPc.rst b/Misc/NEWS.d/next/Core and Builtins/2021-06-05-02-34-57.bpo-44304._MAoPc.rst
new file mode 100644
index 0000000..89104e8
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2021-06-05-02-34-57.bpo-44304._MAoPc.rst
@@ -0,0 +1,2 @@
+Fix a crash in the :mod:`sqlite3` module that happened when the garbage
+collector clears :class:`sqlite.Statement` objects. Patch by Pablo Galindo
diff --git a/Modules/_sqlite/statement.c b/Modules/_sqlite/statement.c
index e6dc4fd..cf7fba6 100644
--- a/Modules/_sqlite/statement.c
+++ b/Modules/_sqlite/statement.c
@@ -397,6 +397,10 @@ stmt_dealloc(pysqlite_Statement *self)
if (self->in_weakreflist != NULL) {
PyObject_ClearWeakRefs((PyObject*)self);
}
+ if (self->st) {
+ sqlite3_finalize(self->st);
+ self->st = 0;
+ }
tp->tp_clear((PyObject *)self);
tp->tp_free(self);
Py_DECREF(tp);
@@ -405,13 +409,6 @@ stmt_dealloc(pysqlite_Statement *self)
static int
stmt_clear(pysqlite_Statement *self)
{
- if (self->st) {
- Py_BEGIN_ALLOW_THREADS
- sqlite3_finalize(self->st);
- Py_END_ALLOW_THREADS
- self->st = 0;
- }
-
Py_CLEAR(self->sql);
return 0;
}