00426: CVE-2023-6597

Combines Two fixes for tempfile.TemporaryDirectory:
python@e9b51c0
python@e9b51c0

Co-authored-by: Søren Løvborg <[email protected]>
Co-authored-by: Serhiy Storchaka <[email protected]>

Author: 3 people

Lib/tempfile.py

@@ -313,6 +313,23 @@ def _resetperms(path):
     _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.
 
 def gettempprefix():

Lib/test/test_tempfile.py

@@ -1299,19 +1299,25 @@ def __exit__(self, *exc_info):
 class TestTemporaryDirectory(BaseTestCase):
     """Test TemporaryDirectory()."""
 
-    def do_create(self, dir=None, pre="", suf="", recurse=1):
+    def do_create(self, dir=None, pre="", suf="", recurse=1, dirs=1, files=1):
         if dir is None:
             dir = tempfile.gettempdir()
         tmp = tempfile.TemporaryDirectory(dir=dir, prefix=pre, suffix=suf)
         self.nameCheck(tmp.name, dir, pre, suf)
-        # Create a subdirectory and some files
-        if recurse:
-            d1 = self.do_create(tmp.name, pre, suf, recurse-1)
-            d1.name = None
-        with open(os.path.join(tmp.name, "test.txt"), "wb") as f:
-            f.write(b"Hello world!")
+        self.do_create2(tmp.name, recurse, dirs, files)
         return tmp
 
+    def do_create2(self, path, recurse=1, dirs=1, files=1):
+        # Create subdirectories and some files
+        if recurse:
+            for i in range(dirs):
+                name = os.path.join(path, "dir%d" % i)
+                os.mkdir(name)
+                self.do_create2(name, recurse-1, dirs, files)
+        for i in range(files):
+            with open(os.path.join(path, "test%d.txt" % i), "wb") as f:
+                f.write(b"Hello world!")
+
     def test_mkdtemp_failure(self):
         # Check no additional exception if mkdtemp fails
         # Previously would raise AttributeError instead
@@ -1351,7 +1357,7 @@ def test_cleanup_with_symlink_to_a_directory(self):
                          "TemporaryDirectory %s exists after cleanup" % d1.name)
         self.assertTrue(os.path.exists(d2.name),
                         "Directory pointed to by a symlink was deleted")
-        self.assertEqual(os.listdir(d2.name), ['test.txt'],
+        self.assertEqual(os.listdir(d2.name), ['test0.txt'],
                          "Contents of the directory pointed to by a symlink "
                          "were deleted")
         d2.cleanup()
@@ -1483,7 +1489,7 @@ def test_del_on_shutdown(self):
 
                     tmp2 = os.path.join(tmp.name, 'test_dir')
                     os.mkdir(tmp2)
-                    with open(os.path.join(tmp2, "test.txt"), "w") as f:
+                    with open(os.path.join(tmp2, "test0.txt"), "w") as f:
                         f.write("Hello world!")
 
                     {mod}.tmp = tmp
@@ -1551,6 +1557,51 @@ def test_context_manager(self):
             self.assertEqual(name, d.name)
         self.assertFalse(os.path.exists(name))
 
+    def test_modes(self):
+        for mode in range(8):
+            mode <<= 6
+            with self.subTest(mode=format(mode, '03o')):
+                d = self.do_create(recurse=3, dirs=2, files=2)
+                with d:
+                    # Change files and directories mode recursively.
+                    for root, dirs, files in os.walk(d.name, topdown=False):
+                        for name in files:
+                            os.chmod(os.path.join(root, name), mode)
+                        os.chmod(root, mode)
+                    d.cleanup()
+                self.assertFalse(os.path.exists(d.name))
+
+    def check_flags(self, flags):
+        # skip the test if these flags are not supported (ex: FreeBSD 13)
+        filename = support.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:
+            support.unlink(filename)
+
+    @unittest.skipUnless(hasattr(os, 'chflags'), 'requires os.lchflags')
+    def test_flags(self):
+        flags = stat.UF_IMMUTABLE | stat.UF_NOUNLINK
+        self.check_flags(flags)
+
+        d = self.do_create(recurse=3, dirs=2, files=2)
+        with d:
+            # Change files and directories flags recursively.
+            for root, dirs, files in os.walk(d.name, topdown=False):
+                for name in files:
+                    os.chflags(os.path.join(root, name), flags)
+                os.chflags(root, flags)
+            d.cleanup()
+        self.assertFalse(os.path.exists(d.name))
+
 
 if __name__ == "__main__":
     unittest.main()