8000 [3.8] gh-80254: Disallow recursive usage of cursors in `sqlite3` conv… · python/cpython@2dc3259 · GitHub
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erlend-aaslandsir-sigurdJelleZijlstra
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[3.8] gh-80254: Disallow recursive usage of cursors in sqlite3 converters
(cherry picked from commit c908dc5) Co-authored-by: Sergey Fedoseev <fedoseev.sergey@gmail.com> Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
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-6
lines changed

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‎Lib/sqlite3/test/regression.py

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@@ -28,6 +28,9 @@
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import functools
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from test import support
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from unittest.mock import patch
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class RegressionTests(unittest.TestCase):
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def setUp(self):
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self.con = sqlite.connect(":memory:")
@@ -413,10 +416,48 @@ def log(self, *args):
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class RecursiveUseOfCursors(unittest.TestCase):
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# GH-80254: sqlite3 should not segfault for recursive use of cursors.
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msg = "Recursive use of cursors not allowed"
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def setUp(self):
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self.con = sqlite.connect(":memory:",
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detect_types=sqlite.PARSE_COLNAMES)
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self.cur = self.con.cursor()
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self.cur.execute("create table test(x foo)")
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self.cur.executemany("insert into test(x) values (?)",
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[("foo",), ("bar",)])
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def tearDown(self):
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self.cur.close()
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self.con.close()
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def test_recursive_cursor_init(self):
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conv = lambda x: self.cur.__init__(self.con)
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with patch.dict(sqlite.converters, {"INIT": conv}):
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with self.assertRaisesRegex(sqlite.ProgrammingError, self.msg):
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self.cur.execute(f'select x as &q 8000 uot;x [INIT]", x from test')
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def test_recursive_cursor_close(self):
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conv = lambda x: self.cur.close()
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with patch.dict(sqlite.converters, {"CLOSE": conv}):
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with self.assertRaisesRegex(sqlite.ProgrammingError, self.msg):
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self.cur.execute(f'select x as "x [CLOSE]", x from test')
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def test_recursive_cursor_fetch(self):
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conv = lambda x, l=[]: self.cur.fetchone() if l else l.append(None)
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with patch.dict(sqlite.converters, {"ITER": conv}):
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self.cur.execute(f'select x as "x [ITER]", x from test')
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with self.assertRaisesRegex(sqlite.ProgrammingError, self.msg):
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self.cur.fetchall()
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def suite():
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regression_suite = unittest.makeSuite(RegressionTests, "Check")
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recursive_cursor = unittest.makeSuite(RecursiveUseOfCursors)
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return unittest.TestSuite((
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regression_suite,
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recursive_cursor,
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))
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def test():

‎Misc/NEWS.d/next/Library/2019-06-22-11-01-45.bpo-36073.ED8mB9.rst

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@@ -0,0 +1,2 @@
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Raise :exc:`~sqlite3.ProgrammingError` instead of segfaulting on recursive
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usage of cursors in :mod:`sqlite3` converters. Patch by Sergey Fedoseev.

‎Modules/_sqlite/cursor.c

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@@ -27,10 +27,25 @@
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PyObject* pysqlite_cursor_iternext(pysqlite_Cursor* self);
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static inline int
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check_cursor_locked(pysqlite_Cursor *cur)
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{
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if (cur->locked) {
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PyErr_SetString(pysqlite_ProgrammingError,
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"Recursive use of cursors not allowed.");
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return 0;
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}
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return 1;
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}
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static const char errmsg_fetch_across_rollback[] = "Cursor needed to be reset because of commit/rollback and can no longer be fetched from.";
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static int pysqlite_cursor_init(pysqlite_Cursor* self, PyObject* args, PyObject* kwargs)
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{
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if (!check_cursor_locked(self)) {
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return -1;
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}
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pysqlite_Connection* connection;
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if (!PyArg_ParseTuple(args, "O!", &pysqlite_ConnectionType, &connection))
@@ -357,12 +372,9 @@ static int check_cursor(pysqlite_Cursor* cur)
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return 0;
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}
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if (cur->locked) {
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PyErr_SetString(pysqlite_ProgrammingError, "Recursive use of cursors not allowed.");
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return 0;
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}
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return pysqlite_check_thread(cur->connection) && pysqlite_check_connection(cur->connection);
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return (pysqlite_check_thread(cur->connection)
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&& pysqlite_check_connection(cur->connection)
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&& check_cursor_locked(cur));
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}
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static PyObject *
@@ -773,7 +785,9 @@ PyObject* pysqlite_cursor_iternext(pysqlite_Cursor *self)
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}
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if (rc == SQLITE_ROW) {
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self->locked = 1; // GH-80254: Prevent recursive use of cursors.
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self->next_row = _pysqlite_fetch_one_row(self);
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self->locked = 0;
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if (self->next_row == NULL) {
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(void)pysqlite_statement_reset(self->statement);
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return NULL;
@@ -876,6 +890,10 @@ PyObject* pysqlite_noop(pysqlite_Connection* self, PyObject* args)
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PyObject* pysqlite_cursor_close(pysqlite_Cursor* self, PyObject* args)
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{
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if (!check_cursor_locked(self)) {
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return NULL;
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}
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if (!self->connection) {
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PyErr_SetString(pysqlite_ProgrammingError,
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"Base Cursor.__init__ not called.");

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