https://github.com/python/cpython/commit/7407267ce47d95d41acd2e7e6a5cc9c0e70d2ccd commit: 7407267ce47d95d41acd2e7e6a5cc9c0e70d2ccd branch: 3.13 author: Miss Islington (bot) <[email protected]> committer: barneygale <[email protected]> date: 2024-05-18T23:12:19Z summary:
[3.13] GH-118447: Fix handling of unreadable symlinks in `os.path.realpath()` (GH-118489) (#119163) (cherry picked from commit caf6064a1bc15ac344afd78b780188e60b9c628e) Co-authored-by: Barney Gale <[email protected]> Co-authored-by: Nice Zombies <[email protected]> files: A Misc/NEWS.d/next/Library/2024-05-01-22-24-05.gh-issue-110863.GjYBbq.rst M Lib/posixpath.py M Lib/test/test_posixpath.py diff --git a/Lib/posixpath.py b/Lib/posixpath.py index b4547d7893b1cd..c04c628de55ee2 100644 --- a/Lib/posixpath.py +++ b/Lib/posixpath.py @@ -471,26 +471,26 @@ def realpath(filename, *, strict=False): if not stat.S_ISLNK(st.st_mode): path = newpath continue + if newpath in seen: + # Already seen this path + path = seen[newpath] + if path is not None: + # use cached value + continue + # The symlink is not resolved, so we must have a symlink loop. + if strict: + # Raise OSError(errno.ELOOP) + os.stat(newpath) + path = newpath + continue + target = os.readlink(newpath) except OSError: if strict: raise path = newpath continue # Resolve the symbolic link - if newpath in seen: - # Already seen this path - path = seen[newpath] - if path is not None: - # use cached value - continue - # The symlink is not resolved, so we must have a symlink loop. - if strict: - # Raise OSError(errno.ELOOP) - os.stat(newpath) - path = newpath - continue seen[newpath] = None # not resolved symlink - target = os.readlink(newpath) if target.startswith(sep): # Symlink target is absolute; reset resolved path. path = sep diff --git a/Lib/test/test_posixpath.py b/Lib/test/test_posixpath.py index 32a20efbb64e1d..5c27b7bee8f60e 100644 --- a/Lib/test/test_posixpath.py +++ b/Lib/test/test_posixpath.py @@ -660,6 +660,23 @@ def test_realpath_resolve_first(self): safe_rmdir(ABSTFN + "/k") safe_rmdir(ABSTFN) + @os_helper.skip_unless_symlink + @skip_if_ABSTFN_contains_backslash + @unittest.skipIf(os.chmod not in os.supports_follow_symlinks, "Can't set symlink permissions") + def test_realpath_unreadable_symlink(self): + try: + os.symlink(ABSTFN+"1", ABSTFN) + os.chmod(ABSTFN, 0o000, follow_symlinks=False) + self.assertEqual(realpath(ABSTFN), ABSTFN) + self.assertEqual(realpath(ABSTFN + '/foo'), ABSTFN + '/foo') + self.assertEqual(realpath(ABSTFN + '/../foo'), dirname(ABSTFN) + '/foo') + self.assertEqual(realpath(ABSTFN + '/foo/..'), ABSTFN) + with self.assertRaises(PermissionError): + realpath(ABSTFN, strict=True) + finally: + os.chmod(ABSTFN, 0o755, follow_symlinks=False) + os.unlink(ABSTFN) + def test_relpath(self): (real_getcwd, os.getcwd) = (os.getcwd, lambda: r"/home/user/bar") try: diff --git a/Misc/NEWS.d/next/Library/2024-05-01-22-24-05.gh-issue-110863.GjYBbq.rst b/Misc/NEWS.d/next/Library/2024-05-01-22-24-05.gh-issue-110863.GjYBbq.rst new file mode 100644 index 00000000000000..37e27a6e37c7d0 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-05-01-22-24-05.gh-issue-110863.GjYBbq.rst @@ -0,0 +1,2 @@ +:func:`os.path.realpath` now suppresses any :exc:`OSError` from +:func:`os.readlink` when *strict* mode is disabled (the default). _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-checkins.python.org/ Member address: [email protected]
