bpo-31764: Prevent a crash in sqlite3.Cursor.close() in case the Cursor object is uninitialized (GH-3958) (#4303)

miss-islington · vstinner · commit b0331c94c2a2 · 2017-11-06T16:45:19.000-08:00
(cherry picked from commit edb13ae)
diff --git a/Lib/sqlite3/test/regression.py b/Lib/sqlite3/test/regression.py
@@ -190,6 +190,9 @@ def __init__(self, con):
         cur = Cursor(con)
         with self.assertRaises(sqlite.ProgrammingError):
             cur.execute("select 4+5").fetchall()
+        with self.assertRaisesRegex(sqlite.ProgrammingError,
+                                    r'^Base Cursor\.__init__ not called\.$'):
+            cur.close()
 
     def CheckStrSubclass(self):
         """
diff --git a/Misc/NEWS.d/next/Library/2017-10-11-22-18-04.bpo-31764.EMyIkK.rst b/Misc/NEWS.d/next/Library/2017-10-11-22-18-04.bpo-31764.EMyIkK.rst
@@ -0,0 +1,2 @@
+Prevent a crash in ``sqlite3.Cursor.close()`` in case the ``Cursor`` object is
+uninitialized. Patch by Oren Milman.
diff --git a/Modules/_sqlite/cursor.c b/Modules/_sqlite/cursor.c
@@ -916,6 +916,11 @@ PyObject* pysqlite_noop(pysqlite_Connection* self, PyObject* args)
 
 PyObject* pysqlite_cursor_close(pysqlite_Cursor* self, PyObject* args)
 {
+    if (!self->connection) {
+        PyErr_SetString(pysqlite_ProgrammingError,
+                        "Base Cursor.__init__ not called.");
+        return NULL;
+    }
     if (!pysqlite_check_thread(self->connection) || !pysqlite_check_connection(self->connection)) {
         return NULL;
     }

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	+Prevent a crash in ``sqlite3.Cursor.close()`` in case the ``Cursor`` object is
	`2`	`+uninitialized. Patch by Oren Milman.`
Original file line number	Diff line number	Diff line change
`@@ -916,6 +916,11 @@ PyObject* pysqlite_noop(pysqlite_Connection* self, PyObject* args)`
`916`	`916`
`917`	`917`	`PyObject* pysqlite_cursor_close(pysqlite_Cursor* self, PyObject* args)`
`918`	`918`	`{`
	`919`	`+ if (!self->connection) {`
	`920`	`+ PyErr_SetString(pysqlite_ProgrammingError,`
	`921`	`+ "Base Cursor.__init__ not called.");`
	`922`	`+ return NULL;`
	`923`	`+ }`
`919`	`924`	`if (!pysqlite_check_thread(self->connection) \|\| !pysqlite_check_connection(self->connection)) {`
`920`	`925`	`return NULL;`
`921`	`926`	`}`