File CVE-2026-3479-pkgutil_get_data.patch of Package python312
From b99e2bfb8c1b1f61377193d51cf627689ec62606 Mon Sep 17 00:00:00 2001
From: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
Date: Wed, 18 Mar 2026 17:31:01 +0000
Subject: [PATCH] gh-146121: `pkgutil.get_data()` reject invalid resource
arguments (GH-146122) (cherry picked from commit
bcdf231946b1da8bdfbab4c05539bb0cc964a1c7)
Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
---
Doc/library/pkgutil.rst | 25 +++++++++-
Lib/pkgutil.py | 3 +
Lib/test/test_pkgutil.py | 19 +++++++
Misc/NEWS.d/next/Security/2026-03-16-18-07-00.gh-issue-146121.vRbdro.rst | 3 +
4 files changed, 48 insertions(+), 2 deletions(-)
create mode 100644 Misc/NEWS.d/next/Security/2026-03-16-18-07-00.gh-issue-146121.vRbdro.rst
Index: Python-3.12.13/Doc/library/pkgutil.rst
===================================================================
--- Python-3.12.13.orig/Doc/library/pkgutil.rst 2026-03-03 13:39:30.000000000 +0100
+++ Python-3.12.13/Doc/library/pkgutil.rst 2026-04-07 23:56:28.234986304 +0200
@@ -191,24 +191,45 @@
:meth:`get_data <importlib.abc.ResourceLoader.get_data>` API. The
*package* argument should be the name of a package, in standard module format
(``foo.bar``). The *resource* argument should be in the form of a relative
- filename, using ``/`` as the path separator. The parent directory name
- ``..`` is not allowed, and nor is a rooted name (starting with a ``/``).
+ filename, using ``/`` as the path separator.
The function returns a binary string that is the contents of the specified
resource.
+ This function uses the :term:`loader` method
+ :func:`~importlib.abc.FileLoader.get_data`
+ to support modules installed in the filesystem, but also in zip files,
+ databases, or elsewhere.
+
For packages located in the filesystem, which have already been imported,
this is the rough equivalent of::
d = os.path.dirname(sys.modules[package].__file__)
data = open(os.path.join(d, resource), 'rb').read()
+ Like the :func:`open` function, :func:`!get_data` can follow parent
+ directories (``../``) and absolute paths (starting with ``/`` or ``C:/``,
+ for example).
+
+ .. warning::
+
+ This function is intended for trusted input.
+ It does not verify that *resource* "belongs" to *package*.
+
+ If you use a user-provided *resource* path, consider verifying it.
+ For example, require an alphanumeric filename with a known extension, or
+ install and check a list of known resources.
+
If the package cannot be located or loaded, or it uses a :term:`loader`
which does not support :meth:`get_data <importlib.abc.ResourceLoader.get_data>`,
then ``None`` is returned. In particular, the :term:`loader` for
:term:`namespace packages <namespace package>` does not support
:meth:`get_data <importlib.abc.ResourceLoader.get_data>`.
+ .. seealso::
+
+ The :mod:`importlib.resources` module provides structured access to
+ module resources.
.. function:: resolve_name(name)
Index: Python-3.12.13/Lib/pkgutil.py
===================================================================
--- Python-3.12.13.orig/Lib/pkgutil.py 2026-04-07 23:56:05.837708559 +0200
+++ Python-3.12.13/Lib/pkgutil.py 2026-04-07 23:56:17.522189128 +0200
@@ -448,6 +448,9 @@
# signature - an os.path format "filename" starting with the dirname of
# the package's __file__
parts = resource.split('/')
+ if os.path.isabs(resource) or '..' in parts:
+ raise ValueError("resource must be a relative path with no "
+ "parent directory components")
parts.insert(0, os.path.dirname(mod.__file__))
resource_name = os.path.join(*parts)
return loader.get_data(resource_name)
Index: Python-3.12.13/Lib/test/test_pkgutil.py
===================================================================
--- Python-3.12.13.orig/Lib/test/test_pkgutil.py 2026-04-07 23:56:07.533481940 +0200
+++ Python-3.12.13/Lib/test/test_pkgutil.py 2026-04-07 23:56:17.522457624 +0200
@@ -61,6 +61,25 @@
del sys.modules[pkg]
+ def test_getdata_path_traversal(self):
+ pkg = 'test_getdata_traversal'
+
+ # Make a package with some resources
+ package_dir = os.path.join(self.dirname, pkg)
+ os.mkdir(package_dir)
+ # Empty init.py
+ f = open(os.path.join(package_dir, '__init__.py'), "wb")
+ f.close()
+
+ with self.assertRaises(ValueError):
+ pkgutil.get_data(pkg, '../../../etc/passwd')
+ with self.assertRaises(ValueError):
+ pkgutil.get_data(pkg, 'sub/../../../etc/passwd')
+ with self.assertRaises(ValueError):
+ pkgutil.get_data(pkg, os.path.abspath('/etc/passwd'))
+
+ del sys.modules[pkg]
+
def test_getdata_zipfile(self):
zip = 'test_getdata_zipfile.zip'
pkg = 'test_getdata_zipfile'
Index: Python-3.12.13/Misc/NEWS.d/next/Security/2026-03-16-18-07-00.gh-issue-146121.vRbdro.rst
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ Python-3.12.13/Misc/NEWS.d/next/Security/2026-03-16-18-07-00.gh-issue-146121.vRbdro.rst 2026-04-07 23:56:17.522707896 +0200
@@ -0,0 +1,3 @@
+:func:`pkgutil.get_data` now raises rejects *resource* arguments containing the
+parent directory components or that is an absolute path.
+This addresses :cve:`2026-3479`.
