diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py index 17e95eb86239a5..5809b2c00060a6 100644 --- a/Lib/test/test_zipfile.py +++ b/Lib/test/test_zipfile.py @@ -3054,6 +3054,83 @@ def test_implied_dirs_performance(self): data = ['/'.join(string.ascii_lowercase + str(n)) for n in range(10000)] zipfile.CompleteDirs._implied_dirs(data) + def test_malformed_paths(self): + """ + Path should handle malformed paths gracefully. + + Paths with leading slashes are not visible. + + Paths with dots are treated like regular files. + """ + data = io.BytesIO() + zf = zipfile.ZipFile(data, "w") + zf.writestr("/one-slash.txt", b"content") + zf.writestr("//two-slash.txt", b"content") + zf.writestr("../parent.txt", b"content") + zf.filename = '' + root = zipfile.Path(zf) + assert list(map(str, root.iterdir())) == ['../'] + assert root.joinpath('..').joinpath('parent.txt').read_bytes() == b'content' + + def test_unsupported_names(self): + """ + Path segments with special characters are readable. + + On some platforms or file systems, characters like + ``:`` and ``?`` are not allowed, but they are valid + in the zip file. + """ + data = io.BytesIO() + zf = zipfile.ZipFile(data, "w") + zf.writestr("path?", b"content") + zf.writestr("V: NMS.flac", b"fLaC...") + zf.filename = '' + root = zipfile.Path(zf) + contents = root.iterdir() + assert next(contents).name == 'path?' + assert next(contents).name == 'V: NMS.flac' + assert root.joinpath('V: NMS.flac').read_bytes() == b"fLaC..." + + def test_backslash_not_separator(self): + """ + In a zip file, backslashes are not separators. + """ + data = io.BytesIO() + zf = zipfile.ZipFile(data, "w") + zf.writestr(DirtyZipInfo.for_name("foo\\bar", zf), b"content") + zf.filename = '' + root = zipfile.Path(zf) + (first,) = root.iterdir() + assert not first.is_dir() + assert first.name == 'foo\\bar' + + +class DirtyZipInfo(zipfile.ZipInfo): + """ + Bypass name sanitization. + """ + + def __init__(self, filename, *args, **kwargs): + super().__init__(filename, *args, **kwargs) + self.filename = filename + + @classmethod + def for_name(cls, name, archive): + """ + Construct the same way that ZipFile.writestr does. + + TODO: extract this functionality and re-use + """ + self = cls(filename=name, date_time=time.localtime(time.time())[:6]) + self.compress_type = archive.compression + self.compress_level = archive.compresslevel + if self.filename.endswith('/'): # pragma: no cover + self.external_attr = 0o40775 << 16 # drwxrwxr-x + self.external_attr |= 0x10 # MS-DOS directory flag + else: + self.external_attr = 0o600 << 16 # ?rw------- + return self + if __name__ == "__main__": unittest.main() diff --git a/Lib/zipfile.py b/Lib/zipfile.py index 95f95ee112667a..68d643ddbdd8e6 100644 --- a/Lib/zipfile.py +++ b/Lib/zipfile.py @@ -2146,7 +2146,7 @@ def _parents(path): def _ancestry(path): """ Given a path with elements separated by - posixpath.sep, generate all elements of that path + posixpath.sep, generate all elements of that path. >>> list(_ancestry('b/d')) ['b/d', 'b'] @@ -2158,9 +2158,14 @@ def _ancestry(path): ['b'] >>> list(_ancestry('')) [] + + Multiple separators are treated like a single. + + >>> list(_ancestry('//b//d///f//')) + ['//b//d///f', '//b//d', '//b'] """ path = path.rstrip(posixpath.sep) - while path and path != posixpath.sep: + while path.rstrip(posixpath.sep): yield path path, tail = posixpath.split(path) diff --git a/Misc/NEWS.d/next/Library/2024-08-26-13-45-20.gh-issue-123270.gXHvNJ.rst b/Misc/NEWS.d/next/Library/2024-08-26-13-45-20.gh-issue-123270.gXHvNJ.rst new file mode 100644 index 00000000000000..ee9fde6a9ed87a --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-08-26-13-45-20.gh-issue-123270.gXHvNJ.rst @@ -0,0 +1,3 @@ +Applied a more surgical fix for malformed payloads in :class:`zipfile.Path` +causing infinite loops (gh-122905) without breaking contents using +legitimate characters.