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#!/usr/bin/python
#
# Copyright (C) 2020 Canonical Ltd
#
# Copying and distribution of this file, with or without modification,
# are permitted in any medium without royalty provided the copyright
# notice and this notice are preserved.
"""Unit tests for verifying the correctness of DebFile descriptor handling."""
import os
import sys
import unittest
from test_all import get_library_dir
libdir = get_library_dir()
if libdir:
sys.path.insert(0, libdir)
import gc
import subprocess
import tempfile
import warnings
import apt_inst
@unittest.skipIf(not os.path.exists("/proc/self/fd"), "no /proc/self/fd available")
class TestCVE_2020_27351(unittest.TestCase):
"""test the debfile"""
GOOD_DEB = "data/test_debs/utf8-package_1.0-1_all.deb"
def test_success(self):
"""opening package successfully should not leak fd"""
before = os.listdir("/proc/self/fd")
apt_inst.DebFile(self.GOOD_DEB)
after = os.listdir("/proc/self/fd")
self.assertEqual(before, after)
def test_regression_bug_977000(self):
"""opening with a file handle should work correctly"""
with open(self.GOOD_DEB) as good_deb:
apt_inst.DebFile(good_deb).control.extractdata("control")
def test_regression_bug_977000_2(self):
"""file object <-> debfile cycles should be collected by gc."""
class Cycle:
def __init__(self, fname):
self.file = open(fname)
self.deb = apt_inst.DebFile(self)
def fileno(self):
return self.file.fileno()
before = os.listdir("/proc/self/fd")
Cycle(self.GOOD_DEB).deb.control.extractdata("control")
warnings.filterwarnings("ignore", category=ResourceWarning)
gc.collect()
warnings.resetwarnings()
after = os.listdir("/proc/self/fd")
self.assertEqual(before, after)
def test_regression_bug_977000_2_ar(self):
"""file object <-> debfile cycles should be collected by gc."""
class Cycle:
def __init__(self, fname):
self.file = open(fname)
self.deb = apt_inst.ArArchive(self)
def fileno(self):
return self.file.fileno()
before = os.listdir("/proc/self/fd")
Cycle(self.GOOD_DEB).deb.gettar("control.tar.gz", "gzip").extractdata("control")
warnings.filterwarnings("ignore", category=ResourceWarning)
gc.collect()
warnings.resetwarnings()
after = os.listdir("/proc/self/fd")
self.assertEqual(before, after)
def test_success_a_member(self):
"""fd should be kept around as long as a tarfile member"""
before = os.listdir("/proc/self/fd")
data = apt_inst.DebFile(self.GOOD_DEB).data
after = os.listdir("/proc/self/fd")
self.assertEqual(len(before), len(after) - 1)
del data
after = os.listdir("/proc/self/fd")
self.assertEqual(before, after)
def _create_deb_without(self, member):
temp = tempfile.NamedTemporaryFile(mode="wb")
try:
with open(self.GOOD_DEB, "rb") as deb:
temp.write(deb.read())
temp.flush()
subprocess.check_call(["ar", "d", temp.name, member])
return temp
except Exception as e:
temp.close()
raise e
def test_nocontrol(self):
"""opening package without control.tar.gz should not leak fd"""
before = os.listdir("/proc/self/fd")
with self._create_deb_without("control.tar.gz") as temp:
try:
apt_inst.DebFile(temp.name)
except SystemError as e:
self.assertIn("control.tar", str(e))
else:
self.fail("Did not raise an exception")
after = os.listdir("/proc/self/fd")
self.assertEqual(before, after)
def test_nodata(self):
"""opening package without data.tar.gz should not leak fd"""
before = os.listdir("/proc/self/fd")
with self._create_deb_without("data.tar.gz") as temp:
try:
apt_inst.DebFile(temp.name)
except SystemError as e:
self.assertIn("data.tar", str(e))
else:
self.fail("Did not raise an exception")
after = os.listdir("/proc/self/fd")
self.assertEqual(before, after)
def test_no_debian_binary(self):
"""opening package without debian-binary should not leak fd"""
before = os.listdir("/proc/self/fd")
with self._create_deb_without("debian-binary") as temp:
try:
apt_inst.DebFile(temp.name)
except SystemError as e:
self.assertIn("missing debian-binary", str(e))
else:
self.fail("Did not raise an exception")
after = os.listdir("/proc/self/fd")
self.assertEqual(before, after)
if __name__ == "__main__":
# logging.basicConfig(level=logging.DEBUG)
unittest.main()
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