--- Lib/tempfile.py | 16 + Lib/test/test_tempfile.py | 113 ++++++++++ Misc/NEWS.d/next/Library/2022-12-01-16-57-44.gh-issue-91133.LKMVCV.rst | 2 3 files changed, 131 insertions(+) Index: Python-3.12.4/Lib/tempfile.py =================================================================== --- Python-3.12.4.orig/Lib/tempfile.py +++ Python-3.12.4/Lib/tempfile.py @@ -285,6 +285,22 @@ def _resetperms(path): _dont_follow_symlinks(chflags, path, 0) _dont_follow_symlinks(_os.chmod, path, 0o700) +def _dont_follow_symlinks(func, path, *args): + # Pass follow_symlinks=False, unless not supported on this platform. + if func in _os.supports_follow_symlinks: + func(path, *args, follow_symlinks=False) + elif _os.name == 'nt' or not _os.path.islink(path): + func(path, *args) + +def _resetperms(path): + try: + chflags = _os.chflags + except AttributeError: + pass + else: + _dont_follow_symlinks(chflags, path, 0) + _dont_follow_symlinks(_os.chmod, path, 0o700) + # User visible interfaces. Index: Python-3.12.4/Lib/test/test_tempfile.py =================================================================== --- Python-3.12.4.orig/Lib/test/test_tempfile.py +++ Python-3.12.4/Lib/test/test_tempfile.py @@ -1803,6 +1803,103 @@ class TestTemporaryDirectory(BaseTestCas new_flags = os.stat(dir1).st_flags self.assertEqual(new_flags, old_flags) + @os_helper.skip_unless_symlink + def test_cleanup_with_symlink_modes(self): + # cleanup() should not follow symlinks when fixing mode bits (#91133) + with self.do_create(recurse=0) as d2: + file1 = os.path.join(d2, 'file1') + open(file1, 'wb').close() + dir1 = os.path.join(d2, 'dir1') + os.mkdir(dir1) + for mode in range(8): + mode <<= 6 + with self.subTest(mode=format(mode, '03o')): + def test(target, target_is_directory): + d1 = self.do_create(recurse=0) + symlink = os.path.join(d1.name, 'symlink') + os.symlink(target, symlink, + target_is_directory=target_is_directory) + try: + os.chmod(symlink, mode, follow_symlinks=False) + except NotImplementedError: + pass + try: + os.chmod(symlink, mode) + except FileNotFoundError: + pass + os.chmod(d1.name, mode) + d1.cleanup() + self.assertFalse(os.path.exists(d1.name)) + + with self.subTest('nonexisting file'): + test('nonexisting', target_is_directory=False) + with self.subTest('nonexisting dir'): + test('nonexisting', target_is_directory=True) + + with self.subTest('existing file'): + os.chmod(file1, mode) + old_mode = os.stat(file1).st_mode + test(file1, target_is_directory=False) + new_mode = os.stat(file1).st_mode + self.assertEqual(new_mode, old_mode, + '%03o != %03o' % (new_mode, old_mode)) + + with self.subTest('existing dir'): + os.chmod(dir1, mode) + old_mode = os.stat(dir1).st_mode + test(dir1, target_is_directory=True) + new_mode = os.stat(dir1).st_mode + self.assertEqual(new_mode, old_mode, + '%03o != %03o' % (new_mode, old_mode)) + + @unittest.skipUnless(hasattr(os, 'chflags'), 'requires os.chflags') + @os_helper.skip_unless_symlink + def test_cleanup_with_symlink_flags(self): + # cleanup() should not follow symlinks when fixing flags (#91133) + flags = stat.UF_IMMUTABLE | stat.UF_NOUNLINK + self.check_flags(flags) + + with self.do_create(recurse=0) as d2: + file1 = os.path.join(d2, 'file1') + open(file1, 'wb').close() + dir1 = os.path.join(d2, 'dir1') + os.mkdir(dir1) + def test(target, target_is_directory): + d1 = self.do_create(recurse=0) + symlink = os.path.join(d1.name, 'symlink') + os.symlink(target, symlink, + target_is_directory=target_is_directory) + try: + os.chflags(symlink, flags, follow_symlinks=False) + except NotImplementedError: + pass + try: + os.chflags(symlink, flags) + except FileNotFoundError: + pass + os.chflags(d1.name, flags) + d1.cleanup() + self.assertFalse(os.path.exists(d1.name)) + + with self.subTest('nonexisting file'): + test('nonexisting', target_is_directory=False) + with self.subTest('nonexisting dir'): + test('nonexisting', target_is_directory=True) + + with self.subTest('existing file'): + os.chflags(file1, flags) + old_flags = os.stat(file1).st_flags + test(file1, target_is_directory=False) + new_flags = os.stat(file1).st_flags + self.assertEqual(new_flags, old_flags) + + with self.subTest('existing dir'): + os.chflags(dir1, flags) + old_flags = os.stat(dir1).st_flags + test(dir1, target_is_directory=True) + new_flags = os.stat(dir1).st_flags + self.assertEqual(new_flags, old_flags) + @support.cpython_only def test_del_on_collection(self): # A TemporaryDirectory is deleted when garbage collected @@ -1977,6 +2074,22 @@ class TestTemporaryDirectory(BaseTestCas def check_flags(self, flags): # skip the test if these flags are not supported (ex: FreeBSD 13) + filename = os_helper.TESTFN + try: + open(filename, "w").close() + try: + os.chflags(filename, flags) + except OSError as exc: + # "OSError: [Errno 45] Operation not supported" + self.skipTest(f"chflags() doesn't support flags " + f"{flags:#b}: {exc}") + else: + os.chflags(filename, 0) + finally: + os_helper.unlink(filename) + + def check_flags(self, flags): + # skip the test if these flags are not supported (ex: FreeBSD 13) filename = os_helper.TESTFN try: open(filename, "w").close() Index: Python-3.12.4/Misc/NEWS.d/next/Library/2022-12-01-16-57-44.gh-issue-91133.LKMVCV.rst =================================================================== --- /dev/null +++ Python-3.12.4/Misc/NEWS.d/next/Library/2022-12-01-16-57-44.gh-issue-91133.LKMVCV.rst @@ -0,0 +1,2 @@ +Fix a bug in :class:`tempfile.TemporaryDirectory` cleanup, which now no longer +dereferences symlinks when working around file system permission errors.