[Python-checkins] [3.10] gh-80254: Disallow recursive usage of cursors in `sqlite3` converters (#92274)
JelleZijlstra
webhook-mailer at python.org
Thu May 5 15:46:31 EDT 2022
https://github.com/python/cpython/commit/2a2421e538f9f7ceb419074909a313ba2c46f384
commit: 2a2421e538f9f7ceb419074909a313ba2c46f384
branch: 3.10
author: Erlend Egeberg Aasland <erlend.aasland at protonmail.com>
committer: JelleZijlstra <jelle.zijlstra at gmail.com>
date: 2022-05-05T12:46:21-07:00
summary:
[3.10] gh-80254: Disallow recursive usage of cursors in `sqlite3` converters (#92274)
* [3.10] gh-80254: Disallow recursive usage of cursors in `sqlite3` converters (#29054)
(cherry picked from commit f629dcfe835e349433e4c5099381d668e8fe69c8)
Co-authored-by: Sergey Fedoseev <fedoseev.sergey at gmail.com>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra at gmail.com>
* Fix ref leak in pysqlite_cursor_iternext
files:
A Misc/NEWS.d/next/Library/2019-06-22-11-01-45.bpo-36073.ED8mB9.rst
M Lib/sqlite3/test/regression.py
M Modules/_sqlite/cursor.c
diff --git a/Lib/sqlite3/test/regression.py b/Lib/sqlite3/test/regression.py
index 70d0ff9af1071..8937f9f69eb03 100644
--- a/Lib/sqlite3/test/regression.py
+++ b/Lib/sqlite3/test/regression.py
@@ -27,6 +27,9 @@
import functools
from test import support
+from unittest.mock import patch
+
+
class RegressionTests(unittest.TestCase):
def setUp(self):
self.con = sqlite.connect(":memory:")
@@ -415,9 +418,46 @@ def test_return_empty_bytestring(self):
self.assertEqual(val, b'')
+class RecursiveUseOfCursors(unittest.TestCase):
+ # GH-80254: sqlite3 should not segfault for recursive use of cursors.
+ msg = "Recursive use of cursors not allowed"
+
+ def setUp(self):
+ self.con = sqlite.connect(":memory:",
+ detect_types=sqlite.PARSE_COLNAMES)
+ self.cur = self.con.cursor()
+ self.cur.execute("create table test(x foo)")
+ self.cur.executemany("insert into test(x) values (?)",
+ [("foo",), ("bar",)])
+
+ def tearDown(self):
+ self.cur.close()
+ self.con.close()
+
+ def test_recursive_cursor_init(self):
+ conv = lambda x: self.cur.__init__(self.con)
+ with patch.dict(sqlite.converters, {"INIT": conv}):
+ with self.assertRaisesRegex(sqlite.ProgrammingError, self.msg):
+ self.cur.execute(f'select x as "x [INIT]", x from test')
+
+ def test_recursive_cursor_close(self):
+ conv = lambda x: self.cur.close()
+ with patch.dict(sqlite.converters, {"CLOSE": conv}):
+ with self.assertRaisesRegex(sqlite.ProgrammingError, self.msg):
+ self.cur.execute(f'select x as "x [CLOSE]", x from test')
+
+ def test_recursive_cursor_fetch(self):
+ conv = lambda x, l=[]: self.cur.fetchone() if l else l.append(None)
+ with patch.dict(sqlite.converters, {"ITER": conv}):
+ self.cur.execute(f'select x as "x [ITER]", x from test')
+ with self.assertRaisesRegex(sqlite.ProgrammingError, self.msg):
+ self.cur.fetchall()
+
+
def suite():
tests = [
- RegressionTests
+ RegressionTests,
+ RecursiveUseOfCursors,
]
return unittest.TestSuite(
[unittest.TestLoader().loadTestsFromTestCase(t) for t in tests]
diff --git a/Misc/NEWS.d/next/Library/2019-06-22-11-01-45.bpo-36073.ED8mB9.rst b/Misc/NEWS.d/next/Library/2019-06-22-11-01-45.bpo-36073.ED8mB9.rst
new file mode 100644
index 0000000000000..6c214d8191601
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-06-22-11-01-45.bpo-36073.ED8mB9.rst
@@ -0,0 +1,2 @@
+Raise :exc:`~sqlite3.ProgrammingError` instead of segfaulting on recursive
+usage of cursors in :mod:`sqlite3` converters. Patch by Sergey Fedoseev.
diff --git a/Modules/_sqlite/cursor.c b/Modules/_sqlite/cursor.c
index 85267cc9e7700..ac80c285fe995 100644
--- a/Modules/_sqlite/cursor.c
+++ b/Modules/_sqlite/cursor.c
@@ -26,6 +26,17 @@
#include "util.h"
#include "clinic/cursor.c.h"
+static inline int
+check_cursor_locked(pysqlite_Cursor *cur)
+{
+ if (cur->locked) {
+ PyErr_SetString(pysqlite_ProgrammingError,
+ "Recursive use of cursors not allowed.");
+ return 0;
+ }
+ return 1;
+}
+
/*[clinic input]
module _sqlite3
class _sqlite3.Cursor "pysqlite_Cursor *" "pysqlite_CursorType"
@@ -47,6 +58,10 @@ pysqlite_cursor_init_impl(pysqlite_Cursor *self,
pysqlite_Connection *connection)
/*[clinic end generated code: output=ac59dce49a809ca8 input=a8a4f75ac90999b2]*/
{
+ if (!check_cursor_locked(self)) {
+ return -1;
+ }
+
Py_INCREF(connection);
Py_XSETREF(self->connection, connection);
Py_CLEAR(self->statement);
@@ -407,12 +422,9 @@ static int check_cursor(pysqlite_Cursor* cur)
return 0;
}
- if (cur->locked) {
- PyErr_SetString(pysqlite_ProgrammingError, "Recursive use of cursors not allowed.");
- return 0;
- }
-
- return pysqlite_check_thread(cur->connection) && pysqlite_check_connection(cur->connection);
+ return (pysqlite_check_thread(cur->connection)
+ && pysqlite_check_connection(cur->connection)
+ && check_cursor_locked(cur));
}
static PyObject *
@@ -810,27 +822,29 @@ pysqlite_cursor_iternext(pysqlite_Cursor *self)
if (self->statement) {
rc = pysqlite_step(self->statement->st, self->connection);
if (PyErr_Occurred()) {
- (void)pysqlite_statement_reset(self->statement);
- Py_DECREF(next_row);
- return NULL;
+ goto error;
}
if (rc != SQLITE_DONE && rc != SQLITE_ROW) {
- (void)pysqlite_statement_reset(self->statement);
- Py_DECREF(next_row);
_pysqlite_seterror(self->connection->db, NULL);
- return NULL;
+ goto error;
}
if (rc == SQLITE_ROW) {
+ self->locked = 1; // GH-80254: Prevent recursive use of cursors.
self->next_row = _pysqlite_fetch_one_row(self);
+ self->locked = 0;
if (self->next_row == NULL) {
- (void)pysqlite_statement_reset(self->statement);
- return NULL;
+ goto error;
}
}
}
return next_row;
+
+error:
+ (void)pysqlite_statement_reset(self->statement);
+ Py_DECREF(next_row);
+ return NULL;
}
/*[clinic input]
@@ -973,6 +987,10 @@ static PyObject *
pysqlite_cursor_close_impl(pysqlite_Cursor *self)
/*[clinic end generated code: output=b6055e4ec6fe63b6 input=08b36552dbb9a986]*/
{
+ if (!check_cursor_locked(self)) {
+ return NULL;
+ }
+
if (!self->connection) {
PyErr_SetString(pysqlite_ProgrammingError,
"Base Cursor.__init__ not called.");
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