python3: CVE-2024-6232 CVE-2024-7592 fixes

Upstream-Status: Backport from b2f11ca766
Upstream-Status: Backport from 743acbe872

(From OE-Core rev: 3e5697687c8fb0aa6312773b233442b8df974feb)

Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource@witekio.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
This commit is contained in:
Hugo SIMELIERE
2024-09-05 20:14:34 +02:00
committed by Steve Sakoman
parent 4cdc553814
commit 85134c7690
3 changed files with 393 additions and 0 deletions

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@@ -0,0 +1,251 @@
From 3a22dc1079be5a75750d24dc6992956e7b84b5a0 Mon Sep 17 00:00:00 2001
From: Seth Michael Larson <seth@python.org>
Date: Tue, 3 Sep 2024 10:07:53 -0500
Subject: [PATCH 2/2] [3.10] gh-121285: Remove backtracking when parsing
tarfile headers (GH-121286) (#123640)
* Remove backtracking when parsing tarfile headers
* Rewrite PAX header parsing to be stricter
* Optimize parsing of GNU extended sparse headers v0.0
(cherry picked from commit 34ddb64d088dd7ccc321f6103d23153256caa5d4)
Upstream-Status: Backport from https://github.com/python/cpython/commit/743acbe872485dc18df4d8ab2dc7895187f062c4
CVE: CVE-2024-6232
Co-authored-by: Kirill Podoprigora <kirill.bast9@mail.ru>
Co-authored-by: Gregory P. Smith <greg@krypto.org>
Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource@witekio.com>
---
Lib/tarfile.py | 105 +++++++++++-------
Lib/test/test_tarfile.py | 42 +++++++
...-07-02-13-39-20.gh-issue-121285.hrl-yI.rst | 2 +
3 files changed, 111 insertions(+), 38 deletions(-)
create mode 100644 Misc/NEWS.d/next/Security/2024-07-02-13-39-20.gh-issue-121285.hrl-yI.rst
diff --git a/Lib/tarfile.py b/Lib/tarfile.py
index 495349f08f9..3ab6811d633 100755
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -841,6 +841,9 @@ def data_filter(member, dest_path):
# Sentinel for replace() defaults, meaning "don't change the attribute"
_KEEP = object()
+# Header length is digits followed by a space.
+_header_length_prefix_re = re.compile(br"([0-9]{1,20}) ")
+
class TarInfo(object):
"""Informational class which holds the details about an
archive member given by a tar header block.
@@ -1410,41 +1413,59 @@ def _proc_pax(self, tarfile):
else:
pax_headers = tarfile.pax_headers.copy()
- # Check if the pax header contains a hdrcharset field. This tells us
- # the encoding of the path, linkpath, uname and gname fields. Normally,
- # these fields are UTF-8 encoded but since POSIX.1-2008 tar
- # implementations are allowed to store them as raw binary strings if
- # the translation to UTF-8 fails.
- match = re.search(br"\d+ hdrcharset=([^\n]+)\n", buf)
- if match is not None:
- pax_headers["hdrcharset"] = match.group(1).decode("utf-8")
-
- # For the time being, we don't care about anything other than "BINARY".
- # The only other value that is currently allowed by the standard is
- # "ISO-IR 10646 2000 UTF-8" in other words UTF-8.
- hdrcharset = pax_headers.get("hdrcharset")
- if hdrcharset == "BINARY":
- encoding = tarfile.encoding
- else:
- encoding = "utf-8"
-
# Parse pax header information. A record looks like that:
# "%d %s=%s\n" % (length, keyword, value). length is the size
# of the complete record including the length field itself and
- # the newline. keyword and value are both UTF-8 encoded strings.
- regex = re.compile(br"(\d+) ([^=]+)=")
+ # the newline.
pos = 0
- while True:
- match = regex.match(buf, pos)
- if not match:
- break
+ encoding = None
+ raw_headers = []
+ while len(buf) > pos and buf[pos] != 0x00:
+ if not (match := _header_length_prefix_re.match(buf, pos)):
+ raise InvalidHeaderError("invalid header")
+ try:
+ length = int(match.group(1))
+ except ValueError:
+ raise InvalidHeaderError("invalid header")
+ # Headers must be at least 5 bytes, shortest being '5 x=\n'.
+ # Value is allowed to be empty.
+ if length < 5:
+ raise InvalidHeaderError("invalid header")
+ if pos + length > len(buf):
+ raise InvalidHeaderError("invalid header")
- length, keyword = match.groups()
- length = int(length)
- if length == 0:
+ header_value_end_offset = match.start(1) + length - 1 # Last byte of the header
+ keyword_and_value = buf[match.end(1) + 1:header_value_end_offset]
+ raw_keyword, equals, raw_value = keyword_and_value.partition(b"=")
+
+ # Check the framing of the header. The last character must be '\n' (0x0A)
+ if not raw_keyword or equals != b"=" or buf[header_value_end_offset] != 0x0A:
raise InvalidHeaderError("invalid header")
- value = buf[match.end(2) + 1:match.start(1) + length - 1]
+ raw_headers.append((length, raw_keyword, raw_value))
+
+ # Check if the pax header contains a hdrcharset field. This tells us
+ # the encoding of the path, linkpath, uname and gname fields. Normally,
+ # these fields are UTF-8 encoded but since POSIX.1-2008 tar
+ # implementations are allowed to store them as raw binary strings if
+ # the translation to UTF-8 fails. For the time being, we don't care about
+ # anything other than "BINARY". The only other value that is currently
+ # allowed by the standard is "ISO-IR 10646 2000 UTF-8" in other words UTF-8.
+ # Note that we only follow the initial 'hdrcharset' setting to preserve
+ # the initial behavior of the 'tarfile' module.
+ if raw_keyword == b"hdrcharset" and encoding is None:
+ if raw_value == b"BINARY":
+ encoding = tarfile.encoding
+ else: # This branch ensures only the first 'hdrcharset' header is used.
+ encoding = "utf-8"
+
+ pos += length
+ # If no explicit hdrcharset is set, we use UTF-8 as a default.
+ if encoding is None:
+ encoding = "utf-8"
+
+ # After parsing the raw headers we can decode them to text.
+ for length, raw_keyword, raw_value in raw_headers:
# Normally, we could just use "utf-8" as the encoding and "strict"
# as the error handler, but we better not take the risk. For
# example, GNU tar <= 1.23 is known to store filenames it cannot
@@ -1452,17 +1473,16 @@ def _proc_pax(self, tarfile):
# hdrcharset=BINARY header).
# We first try the strict standard encoding, and if that fails we
# fall back on the user's encoding and error handler.
- keyword = self._decode_pax_field(keyword, "utf-8", "utf-8",
+ keyword = self._decode_pax_field(raw_keyword, "utf-8", "utf-8",
tarfile.errors)
if keyword in PAX_NAME_FIELDS:
- value = self._decode_pax_field(value, encoding, tarfile.encoding,
+ value = self._decode_pax_field(raw_value, encoding, tarfile.encoding,
tarfile.errors)
else:
- value = self._decode_pax_field(value, "utf-8", "utf-8",
+ value = self._decode_pax_field(raw_value, "utf-8", "utf-8",
tarfile.errors)
pax_headers[keyword] = value
- pos += length
# Fetch the next header.
try:
@@ -1477,7 +1497,7 @@ def _proc_pax(self, tarfile):
elif "GNU.sparse.size" in pax_headers:
# GNU extended sparse format version 0.0.
- self._proc_gnusparse_00(next, pax_headers, buf)
+ self._proc_gnusparse_00(next, raw_headers)
elif pax_headers.get("GNU.sparse.major") == "1" and pax_headers.get("GNU.sparse.minor") == "0":
# GNU extended sparse format version 1.0.
@@ -1499,15 +1519,24 @@ def _proc_pax(self, tarfile):
return next
- def _proc_gnusparse_00(self, next, pax_headers, buf):
+ def _proc_gnusparse_00(self, next, raw_headers):
"""Process a GNU tar extended sparse header, version 0.0.
"""
offsets = []
- for match in re.finditer(br"\d+ GNU.sparse.offset=(\d+)\n", buf):
- offsets.append(int(match.group(1)))
numbytes = []
- for match in re.finditer(br"\d+ GNU.sparse.numbytes=(\d+)\n", buf):
- numbytes.append(int(match.group(1)))
+ for _, keyword, value in raw_headers:
+ if keyword == b"GNU.sparse.offset":
+ try:
+ offsets.append(int(value.decode()))
+ except ValueError:
+ raise InvalidHeaderError("invalid header")
+
+ elif keyword == b"GNU.sparse.numbytes":
+ try:
+ numbytes.append(int(value.decode()))
+ except ValueError:
+ raise InvalidHeaderError("invalid header")
+
next.sparse = list(zip(offsets, numbytes))
def _proc_gnusparse_01(self, next, pax_headers):
diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py
index cfc13bccb20..007c3e94acb 100644
--- a/Lib/test/test_tarfile.py
+++ b/Lib/test/test_tarfile.py
@@ -1139,6 +1139,48 @@ def test_pax_number_fields(self):
finally:
tar.close()
+ def test_pax_header_bad_formats(self):
+ # The fields from the pax header have priority over the
+ # TarInfo.
+ pax_header_replacements = (
+ b" foo=bar\n",
+ b"0 \n",
+ b"1 \n",
+ b"2 \n",
+ b"3 =\n",
+ b"4 =a\n",
+ b"1000000 foo=bar\n",
+ b"0 foo=bar\n",
+ b"-12 foo=bar\n",
+ b"000000000000000000000000036 foo=bar\n",
+ )
+ pax_headers = {"foo": "bar"}
+
+ for replacement in pax_header_replacements:
+ with self.subTest(header=replacement):
+ tar = tarfile.open(tmpname, "w", format=tarfile.PAX_FORMAT,
+ encoding="iso8859-1")
+ try:
+ t = tarfile.TarInfo()
+ t.name = "pax" # non-ASCII
+ t.uid = 1
+ t.pax_headers = pax_headers
+ tar.addfile(t)
+ finally:
+ tar.close()
+
+ with open(tmpname, "rb") as f:
+ data = f.read()
+ self.assertIn(b"11 foo=bar\n", data)
+ data = data.replace(b"11 foo=bar\n", replacement)
+
+ with open(tmpname, "wb") as f:
+ f.truncate()
+ f.write(data)
+
+ with self.assertRaisesRegex(tarfile.ReadError, r"method tar: ReadError\('invalid header'\)"):
+ tarfile.open(tmpname, encoding="iso8859-1")
+
class WriteTestBase(TarTest):
# Put all write tests in here that are supposed to be tested
diff --git a/Misc/NEWS.d/next/Security/2024-07-02-13-39-20.gh-issue-121285.hrl-yI.rst b/Misc/NEWS.d/next/Security/2024-07-02-13-39-20.gh-issue-121285.hrl-yI.rst
new file mode 100644
index 00000000000..81f918bfe2b
--- /dev/null
+++ b/Misc/NEWS.d/next/Security/2024-07-02-13-39-20.gh-issue-121285.hrl-yI.rst
@@ -0,0 +1,2 @@
+Remove backtracking from tarfile header parsing for ``hdrcharset``, PAX, and
+GNU sparse headers.
--
2.46.0

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@@ -0,0 +1,140 @@
From 3c15b8437f57fe1027171b34af88bf791cf1868c Mon Sep 17 00:00:00 2001
From: "Miss Islington (bot)"
<31488909+miss-islington@users.noreply.github.com>
Date: Wed, 4 Sep 2024 17:50:36 +0200
Subject: [PATCH 1/2] [3.10] gh-123067: Fix quadratic complexity in parsing
"-quoted cookie values with backslashes (GH-123075) (#123106)
This fixes CVE-2024-7592.
(cherry picked from commit 44e458357fca05ca0ae2658d62c8c595b048b5ef)
Upstream-Status: Backport from https://github.com/python/cpython/commit/b2f11ca7667e4d57c71c1c88b255115f16042d9a
CVE: CVE-2024-7592
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource@witekio.com>
---
Lib/http/cookies.py | 34 ++++-------------
Lib/test/test_http_cookies.py | 38 +++++++++++++++++++
...-08-16-19-13-21.gh-issue-123067.Nx9O4R.rst | 1 +
3 files changed, 47 insertions(+), 26 deletions(-)
create mode 100644 Misc/NEWS.d/next/Library/2024-08-16-19-13-21.gh-issue-123067.Nx9O4R.rst
diff --git a/Lib/http/cookies.py b/Lib/http/cookies.py
index 35ac2dc6ae2..2c1f021d0ab 100644
--- a/Lib/http/cookies.py
+++ b/Lib/http/cookies.py
@@ -184,8 +184,13 @@ def _quote(str):
return '"' + str.translate(_Translator) + '"'
-_OctalPatt = re.compile(r"\\[0-3][0-7][0-7]")
-_QuotePatt = re.compile(r"[\\].")
+_unquote_sub = re.compile(r'\\(?:([0-3][0-7][0-7])|(.))').sub
+
+def _unquote_replace(m):
+ if m[1]:
+ return chr(int(m[1], 8))
+ else:
+ return m[2]
def _unquote(str):
# If there aren't any doublequotes,
@@ -205,30 +210,7 @@ def _unquote(str):
# \012 --> \n
# \" --> "
#
- i = 0
- n = len(str)
- res = []
- while 0 <= i < n:
- o_match = _OctalPatt.search(str, i)
- q_match = _QuotePatt.search(str, i)
- if not o_match and not q_match: # Neither matched
- res.append(str[i:])
- break
- # else:
- j = k = -1
- if o_match:
- j = o_match.start(0)
- if q_match:
- k = q_match.start(0)
- if q_match and (not o_match or k < j): # QuotePatt matched
- res.append(str[i:k])
- res.append(str[k+1])
- i = k + 2
- else: # OctalPatt matched
- res.append(str[i:j])
- res.append(chr(int(str[j+1:j+4], 8)))
- i = j + 4
- return _nulljoin(res)
+ return _unquote_sub(_unquote_replace, str)
# The _getdate() routine is used to set the expiration time in the cookie's HTTP
# header. By default, _getdate() returns the current time in the appropriate
diff --git a/Lib/test/test_http_cookies.py b/Lib/test/test_http_cookies.py
index 6072c7e15e9..644e75cd5b7 100644
--- a/Lib/test/test_http_cookies.py
+++ b/Lib/test/test_http_cookies.py
@@ -5,6 +5,7 @@
import unittest
from http import cookies
import pickle
+from test import support
class CookieTests(unittest.TestCase):
@@ -58,6 +59,43 @@ def test_basic(self):
for k, v in sorted(case['dict'].items()):
self.assertEqual(C[k].value, v)
+ def test_unquote(self):
+ cases = [
+ (r'a="b=\""', 'b="'),
+ (r'a="b=\\"', 'b=\\'),
+ (r'a="b=\="', 'b=='),
+ (r'a="b=\n"', 'b=n'),
+ (r'a="b=\042"', 'b="'),
+ (r'a="b=\134"', 'b=\\'),
+ (r'a="b=\377"', 'b=\xff'),
+ (r'a="b=\400"', 'b=400'),
+ (r'a="b=\42"', 'b=42'),
+ (r'a="b=\\042"', 'b=\\042'),
+ (r'a="b=\\134"', 'b=\\134'),
+ (r'a="b=\\\""', 'b=\\"'),
+ (r'a="b=\\\042"', 'b=\\"'),
+ (r'a="b=\134\""', 'b=\\"'),
+ (r'a="b=\134\042"', 'b=\\"'),
+ ]
+ for encoded, decoded in cases:
+ with self.subTest(encoded):
+ C = cookies.SimpleCookie()
+ C.load(encoded)
+ self.assertEqual(C['a'].value, decoded)
+
+ @support.requires_resource('cpu')
+ def test_unquote_large(self):
+ n = 10**6
+ for encoded in r'\\', r'\134':
+ with self.subTest(encoded):
+ data = 'a="b=' + encoded*n + ';"'
+ C = cookies.SimpleCookie()
+ C.load(data)
+ value = C['a'].value
+ self.assertEqual(value[:3], 'b=\\')
+ self.assertEqual(value[-2:], '\\;')
+ self.assertEqual(len(value), n + 3)
+
def test_load(self):
C = cookies.SimpleCookie()
C.load('Customer="WILE_E_COYOTE"; Version=1; Path=/acme')
diff --git a/Misc/NEWS.d/next/Library/2024-08-16-19-13-21.gh-issue-123067.Nx9O4R.rst b/Misc/NEWS.d/next/Library/2024-08-16-19-13-21.gh-issue-123067.Nx9O4R.rst
new file mode 100644
index 00000000000..6a234561fe3
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-08-16-19-13-21.gh-issue-123067.Nx9O4R.rst
@@ -0,0 +1 @@
+Fix quadratic complexity in parsing ``"``-quoted cookie values with backslashes by :mod:`http.cookies`.
--
2.46.0