From fc0b8259e693caa8400fa8b6ac1e494e47ea7798 Mon Sep 17 00:00:00 2001 From: "Jason R. Coombs" Date: Wed, 4 Sep 2024 11:52:54 -0400 Subject: [PATCH] [3.11] gh-123270: Replaced SanitizedNames with a more surgical fix. (GH-123354) (#123425) Applies changes from zipp 3.20.1 and jaraco/zippGH-124 (cherry picked from commit 2231286d78d328c2f575e0b05b16fe447d1656d6) Co-authored-by: Jason R. Coombs * Restore the slash-prefixed paths in the malformed_paths test. Origin: upstream, https://github.com/python/cpython/commit/fc0b8259e693caa8400fa8b6ac1e494e47ea7798 Bug-Debian: https://bugs.debian.org/1080245 --- Lib/test/test_zipfile.py | 72 +++++++++++++++++-- Lib/zipfile.py | 69 +++--------------- ...-08-26-13-45-20.gh-issue-123270.gXHvNJ.rst | 3 + 3 files changed, 77 insertions(+), 67 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2024-08-26-13-45-20.gh-issue-123270.gXHvNJ.rst Index: python3/Lib/test/test_zipfile.py =================================================================== --- python3.orig/Lib/test/test_zipfile.py +++ python3/Lib/test/test_zipfile.py @@ -3546,7 +3546,11 @@ class EncodedMetadataTests(unittest.Test def test_malformed_paths(self): """ - Path should handle malformed paths. + 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") @@ -3555,11 +3559,67 @@ class EncodedMetadataTests(unittest.Test zf.writestr("../parent.txt", b"content") zf.filename = '' root = zipfile.Path(zf) - assert list(map(str, root.iterdir())) == [ - 'one-slash.txt', - 'two-slash.txt', - 'parent.txt', - ] + 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__": Index: python3/Lib/zipfile.py =================================================================== --- python3.orig/Lib/zipfile.py +++ python3/Lib/zipfile.py @@ -2201,7 +2201,7 @@ 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'] @@ -2213,9 +2213,14 @@ 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) @@ -2232,65 +2237,7 @@ def _difference(minuend, subtrahend): return itertools.filterfalse(set(subtrahend).__contains__, minuend) -class SanitizedNames: - """ - ZipFile mix-in to ensure names are sanitized. - """ - - def namelist(self): - return list(map(self._sanitize, super().namelist())) - - @staticmethod - def _sanitize(name): - r""" - Ensure a relative path with posix separators and no dot names. - Modeled after - https://github.com/python/cpython/blob/bcc1be39cb1d04ad9fc0bd1b9193d3972835a57c/Lib/zipfile/__init__.py#L1799-L1813 - but provides consistent cross-platform behavior. - >>> san = SanitizedNames._sanitize - >>> san('/foo/bar') - 'foo/bar' - >>> san('//foo.txt') - 'foo.txt' - >>> san('foo/.././bar.txt') - 'foo/bar.txt' - >>> san('foo../.bar.txt') - 'foo../.bar.txt' - >>> san('\\foo\\bar.txt') - 'foo/bar.txt' - >>> san('D:\\foo.txt') - 'D/foo.txt' - >>> san('\\\\server\\share\\file.txt') - 'server/share/file.txt' - >>> san('\\\\?\\GLOBALROOT\\Volume3') - '?/GLOBALROOT/Volume3' - >>> san('\\\\.\\PhysicalDrive1\\root') - 'PhysicalDrive1/root' - Retain any trailing slash. - >>> san('abc/') - 'abc/' - Raises a ValueError if the result is empty. - >>> san('../..') - Traceback (most recent call last): - ... - ValueError: Empty filename - """ - - def allowed(part): - return part and part not in {'..', '.'} - - # Remove the drive letter. - # Don't use ntpath.splitdrive, because that also strips UNC paths - bare = re.sub('^([A-Z]):', r'\1', name, flags=re.IGNORECASE) - clean = bare.replace('\\', '/') - parts = clean.split('/') - joined = '/'.join(filter(allowed, parts)) - if not joined: - raise ValueError("Empty filename") - return joined + '/' * name.endswith('/') - - -class CompleteDirs(SanitizedNames, ZipFile): +class CompleteDirs(ZipFile): """ A ZipFile subclass that ensures that implied directories are always included in the namelist. Index: python3/Misc/NEWS.d/next/Library/2024-08-26-13-45-20.gh-issue-123270.gXHvNJ.rst =================================================================== --- /dev/null +++ python3/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.