[3.11] gh-135034: Normalize link targets in tarfile, add os.path.realpath(strict='allow_missing') (GH-135037)
#135068
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…th.realpath(strict='allow_missing')` (pythonGH-135037) Addresses CVEs 2024-12718, 2025-4138, 2025-4330, and 2025-4517. (cherry picked from commit 3612d8f) (cherry picked from commit c358142) Co-authored-by: Łukasz Langa <lukasz@langa.pl> Signed-off-by: Łukasz Langa <lukasz@langa.pl> Co-authored-by: Petr Viktorin <encukou@gmail.com> Co-authored-by: Seth Michael Larson <seth@python.org> Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com> Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
security backports.
This was referenced Jun 3, 2025
Merged
non-strict test for unreadable symlinks, whch isn't supported before 3.13.
encukou
approved these changes
Jun 3, 2025
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After this update, I am getting the following test failure: ======================================================================
ERROR: test_realpath_limit_attack (test.test_tarfile.TestExtractionFilters.test_realpath_limit_attack) [fully_trusted]
----------------------------------------------------------------------
Traceback (most recent call last):
File "/builds/jkulik/python-3.13.4-3.11.13-3.9.23/components/python/python311/Python-3.11.13/Lib/test/test_tarfile.py", line 3669, in test_realpath_limit_attack
with (self.subTest('fully_trusted'),
File "/builds/jkulik/python-3.13.4-3.11.13-3.9.23/components/python/python311/Python-3.11.13/Lib/contextlib.py", line 137, in __enter__
return next(self.gen)
^^^^^^^^^^^^^^
File "/builds/jkulik/python-3.13.4-3.11.13-3.9.23/components/python/python311/Python-3.11.13/Lib/test/test_tarfile.py", line 3458, in check_context
self.expected_paths = set(self.outerdir.glob('**/*'))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/builds/jkulik/python-3.13.4-3.11.13-3.9.23/components/python/python311/Python-3.11.13/Lib/pathlib.py", line 958, in glob
for p in selector.select_from(self):
File "/builds/jkulik/python-3.13.4-3.11.13-3.9.23/components/python/python311/Python-3.11.13/Lib/pathlib.py", line 411, in _select_from
for starting_point in self._iterate_directories(parent_path, is_dir, scandir):
File "/builds/jkulik/python-3.13.4-3.11.13-3.9.23/components/python/python311/Python-3.11.13/Lib/pathlib.py", line 401, in _iterate_directories
for p in self._iterate_directories(path, is_dir, scandir):
File "/builds/jkulik/python-3.13.4-3.11.13-3.9.23/components/python/python311/Python-3.11.13/Lib/pathlib.py", line 401, in _iterate_directories
for p in self._iterate_directories(path, is_dir, scandir):
File "/builds/jkulik/python-3.13.4-3.11.13-3.9.23/components/python/python311/Python-3.11.13/Lib/pathlib.py", line 401, in _iterate_directories
for p in self._iterate_directories(path, is_dir, scandir):
[Previous line repeated 14 more times]
File "/builds/jkulik/python-3.13.4-3.11.13-3.9.23/components/python/python311/Python-3.11.13/Lib/pathlib.py", line 395, in _iterate_directories
entry_is_dir = entry.is_dir(follow_symlinks=False)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: [Errno 78] File name too long: '/builds/jkulik/python-3.13.4-3.11.13-3.9.23/components/python/python311/build/amd64/build/test_python_22904æ/@test_22904_tmpæ-tardir/outerdir/dest/ddddddddddddddddddd
dddddddddddddddddddddddddddddddd/ddddddddddddddddddddddddddddddddddddddddddddddddddd/ddddddddddddddddddddddddddddddddddddddddddddddddddd/ddddddddddddddddddddddddddddddddddddddddddddddddddd/dddddddddddddddddd
ddddddddddddddddddddddddddddddddd/ddddddddddddddddddddddddddddddddddddddddddddddddddd/ddddddddddddddddddddddddddddddddddddddddddddddddddd/ddddddddddddddddddddddddddddddddddddddddddddddddddd/ddddddddddddddddd
dddddddddddddddddddddddddddddddddd/ddddddddddddddddddddddddddddddddddddddddddddddddddd/ddddddddddddddddddddddddddddddddddddddddddddddddddd/ddddddddddddddddddddddddddddddddddddddddddddddddddd/dddddddddddddddd
ddddddddddddddddddddddddddddddddddd/ddddddddddddddddddddddddddddddddddddddddddddddddddd/ddddddddddddddddddddddddddddddddddddddddddddddddddd/ddddddddddddddddddddddddddddddddddddddddddddddddddd/lllllllllllllll
lllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll
llllllllllllllllllllllllllllllll'Interestingly, it's just 3.11.13 that's failing - both 3.9.23 and 3.13.4 (and all other supported versions we are running in our internal buildbot) pass. 3.13 has a very different pathlib implementation, but 3.9 is pretty similar so I investigated the differences, and when I print the entires from here (_iterate_directories 3.9 / 3.11): I get very different results: 3.11: Also, the This is on Oracle Solaris. |
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Ah! We got the same test failure in 3.10, so I hotfixed it there. Try applying the hack to 3.11: dff62a1 It's just a test failure: if the filter is |
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Oh, that fixed it. Thanks! (i didn't realize that this difference between 3.9 and 3.11 is what causes the issue) |
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Hello, sorry to ask directly here but i haven't understood how 3.10 & 3.11 are affected by these CVEs, since the description of each CVE states that ONLY versions after 3.12 are affected, since the extraction filters were first introduced in 3.12 |
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yeah, looks like the CVE text needs an update :( |
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@encukou Gotcha, I didn't realize that filtering had been backported, I'll update the prose description in each document. The affectedness of the CVEs is correct thankfully :) |
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Updated the CVE records and sent a correction to |
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Addresses CVEs 2024-12718, 2025-4138, 2025-4330, and 2025-4517.
(cherry picked from commit 3612d8f)
Co-authored-by: Łukasz Langa lukasz@langa.pl
Co-authored-by: Petr Viktorin encukou@gmail.com
Co-authored-by: Seth Michael Larson seth@python.org
Co-authored-by: Adam Turner 9087854+AA-Turner@users.noreply.github.com
Co-authored-by: Serhiy Storchaka storchaka@gmail.com
filter="tar"/filter="data") #135034📚 Documentation preview 📚: https://cpython-previews--135068.org.readthedocs.build/