File CVE-2025-12084-minidom-quad-search.patch of Package python3.42038
From f4eb9ab014545b521fb261b80adfa6d138e7e092 Mon Sep 17 00:00:00 2001
From: Seth Michael Larson <seth@python.org>
Date: Wed, 3 Dec 2025 01:16:37 -0600
Subject: [PATCH] gh-142145: Remove quadratic behavior in node ID cache
clearing (GH-142146)
* Remove quadratic behavior in node ID cache clearing
Co-authored-by: Jacob Walls <38668450+jacobtylerwalls@users.noreply.github.com>
* Add news fragment
---------
(cherry picked from commit 08d8e18ad81cd45bc4a27d6da478b51ea49486e4)
Co-authored-by: Seth Michael Larson <seth@python.org>
Co-authored-by: Jacob Walls <38668450+jacobtylerwalls@users.noreply.github.com>
---
Lib/test/test_minidom.py | 18 ++++++++++
Lib/xml/dom/minidom.py | 9 -----
Misc/NEWS.d/next/Security/2025-12-01-09-36-45.gh-issue-142145.tcAUhg.rst | 1
3 files changed, 20 insertions(+), 8 deletions(-)
create mode 100644 Misc/NEWS.d/next/Security/2025-12-01-09-36-45.gh-issue-142145.tcAUhg.rst
Index: Python-3.6.15/Lib/test/test_minidom.py
===================================================================
--- Python-3.6.15.orig/Lib/test/test_minidom.py 2025-12-20 20:02:31.594672148 +0100
+++ Python-3.6.15/Lib/test/test_minidom.py 2025-12-20 20:04:27.310278898 +0100
@@ -2,6 +2,7 @@
import copy
import pickle
+import time
from test import support
import unittest
@@ -171,6 +172,23 @@
self.confirm(dom.documentElement.childNodes[-1].data == "Hello")
dom.unlink()
+ def testAppendChildNoQuadraticComplexity(self):
+ impl = getDOMImplementation()
+
+ newdoc = impl.createDocument(None, "some_tag", None)
+ top_element = newdoc.documentElement
+ children = [newdoc.createElement(f"child-{i}") for i in range(1, 2 ** 15 + 1)]
+ element = top_element
+
+ start = time.time()
+ for child in children:
+ element.appendChild(child)
+ element = child
+ end = time.time()
+
+ # This example used to take at least 30 seconds.
+ self.assertLess(end - start, 1)
+
def testAppendChildFragment(self):
dom, orig, c1, c2, c3, frag = self._create_fragment_test_nodes()
dom.documentElement.appendChild(frag)
Index: Python-3.6.15/Lib/xml/dom/minidom.py
===================================================================
--- Python-3.6.15.orig/Lib/xml/dom/minidom.py 2025-12-20 20:02:31.594672148 +0100
+++ Python-3.6.15/Lib/xml/dom/minidom.py 2025-12-20 20:04:27.311120771 +0100
@@ -291,13 +291,6 @@
childNodes.append(node)
node.parentNode = self
-def _in_document(node):
- # return True iff node is part of a document tree
- while node is not None:
- if node.nodeType == Node.DOCUMENT_NODE:
- return True
- node = node.parentNode
- return False
def _write_data(writer, data):
"Writes datachars to writer."
@@ -1512,7 +1505,7 @@
if node.nodeType == Node.DOCUMENT_NODE:
node._id_cache.clear()
node._id_search_stack = None
- elif _in_document(node):
+ elif node.ownerDocument:
node.ownerDocument._id_cache.clear()
node.ownerDocument._id_search_stack= None
Index: Python-3.6.15/Misc/NEWS.d/next/Security/2025-12-01-09-36-45.gh-issue-142145.tcAUhg.rst
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ Python-3.6.15/Misc/NEWS.d/next/Security/2025-12-01-09-36-45.gh-issue-142145.tcAUhg.rst 2025-12-20 20:04:27.311549530 +0100
@@ -0,0 +1 @@
+Remove quadratic behavior in ``xml.minidom`` node ID cache clearing.
