python3-tornado: patch CVE-2025-67726

Details: https://nvd.nist.gov/vuln/detail/CVE-2025-67726

Signed-off-by: Ankur Tyagi <ankur.tyagi85@gmail.com>
Signed-off-by: Anuj Mittal <anuj.mittal@oss.qualcomm.com>

meta-python/recipes-devtools/python/python3-tornado/CVE-2025-67726.patch

@@ -0,0 +1,99 @@
+From 4cdca826270483d8b774461a5fdd64f61af62659 Mon Sep 17 00:00:00 2001
+From: Ben Darnell <ben@bendarnell.com>
+Date: Wed, 10 Dec 2025 10:55:02 -0500
+Subject: [PATCH] httputil: Fix quadratic behavior in _parseparam
+
+Prior to this change, _parseparam had O(n^2) behavior when parsing
+certain inputs, which could be a DoS vector. This change adapts
+logic from the equivalent function in the python standard library
+in https://github.com/python/cpython/pull/136072/files
+
+CVE: CVE-2025-67726
+Upstream-Status: Backport [https://github.com/tornadoweb/tornado/commit/771472cfdaeebc0d89a9cc46e249f8891a6b29cd]
+(cherry picked from commit 771472cfdaeebc0d89a9cc46e249f8891a6b29cd)
+Signed-off-by: Ankur Tyagi <ankur.tyagi85@gmail.com>
+---
+ tornado/httputil.py           | 29 ++++++++++++++++++++++-------
+ tornado/test/httputil_test.py | 23 +++++++++++++++++++++++
+ 2 files changed, 45 insertions(+), 7 deletions(-)
+
+diff --git a/tornado/httputil.py b/tornado/httputil.py
+index 090a977d..bbacd4a4 100644
+--- a/tornado/httputil.py
++++ b/tornado/httputil.py
+@@ -926,19 +926,34 @@ def parse_response_start_line(line: str) -> ResponseStartLine:
+ # It has also been modified to support valueless parameters as seen in
+ # websocket extension negotiations, and to support non-ascii values in
+ # RFC 2231/5987 format.
++#
++# _parseparam has been further modified with the logic from
++# https://github.com/python/cpython/pull/136072/files
++# to avoid quadratic behavior when parsing semicolons in quoted strings.
++#
++# TODO: See if we can switch to email.message.Message for this functionality.
++# This is the suggested replacement for the cgi.py module now that cgi has
++# been removed from recent versions of Python.  We need to verify that
++# the email module is consistent with our existing behavior (and all relevant
++# RFCs for multipart/form-data) before making this change.
+ 
+ 
+ def _parseparam(s: str) -> Generator[str, None, None]:
+-    while s[:1] == ";":
+-        s = s[1:]
+-        end = s.find(";")
+-        while end > 0 and (s.count('"', 0, end) - s.count('\\"', 0, end)) % 2:
+-            end = s.find(";", end + 1)
++    start = 0
++    while s.find(";", start) == start:
++        start += 1
++        end = s.find(";", start)
++        ind, diff = start, 0
++        while end > 0:
++            diff += s.count('"', ind, end) - s.count('\\"', ind, end)
++            if diff % 2 == 0:
++                break
++            end, ind = ind, s.find(";", end + 1)
+         if end < 0:
+             end = len(s)
+-        f = s[:end]
++        f = s[start:end]
+         yield f.strip()
+-        s = s[end:]
++        start = end
+ 
+ 
+ def _parse_header(line: str) -> Tuple[str, Dict[str, str]]:
+diff --git a/tornado/test/httputil_test.py b/tornado/test/httputil_test.py
+index 9494d0c1..22b1681b 100644
+--- a/tornado/test/httputil_test.py
++++ b/tornado/test/httputil_test.py
+@@ -262,6 +262,29 @@ Foo
+         self.assertEqual(file["filename"], "ab.txt")
+         self.assertEqual(file["body"], b"Foo")
+ 
++    def test_disposition_param_linear_performance(self):
++        # This is a regression test for performance of parsing parameters
++        # to the content-disposition header, specifically for semicolons within
++        # quoted strings.
++        def f(n):
++            start = time.time()
++            message = (
++                b"--1234\r\nContent-Disposition: form-data; "
++                + b'x="'
++                + b";" * n
++                + b'"; '
++                + b'name="files"; filename="a.txt"\r\n\r\nFoo\r\n--1234--\r\n'
++            )
++            args: dict[str, list[bytes]] = {}
++            files: dict[str, list[HTTPFile]] = {}
++            parse_multipart_form_data(b"1234", message, args, files)
++            return time.time() - start
++
++        d1 = f(1_000)
++        d2 = f(10_000)
++        if d2 / d1 > 20:
++            self.fail(f"Disposition param parsing is not linear: {d1=} vs {d2=}")
++
+ 
+ class HTTPHeadersTest(unittest.TestCase):
+     def test_multi_line(self):

meta-python/recipes-devtools/python/python3-tornado_6.4.2.bb

@@ -10,6 +10,7 @@ SRC_URI[sha256sum] = "92bad5b4746e9879fd7bf1eb21dce4e3fc5128d71601f80005afa39237
 
 SRC_URI += "file://CVE-2025-47287.patch \
             file://CVE-2025-67724.patch \
+            file://CVE-2025-67726.patch \
 "
 
 inherit pypi python_setuptools_build_meta