Revert "Fix cfntools command injection"

This reverts commit e424af2236.

Splitting command strings that were previously assumed to be interpreted
by the shell at whitespace and then passing them as separate args to
execvp will not work.

Change-Id: I7c37b5852ce9b20e63bdbbaddfb852463548aa90
This commit is contained in:
Zane Bitter 2015-09-03 18:16:26 -04:00
parent e424af2236
commit 090a14dd63
2 changed files with 10 additions and 65 deletions

View File

@ -180,23 +180,7 @@ class CommandRunner(object):
self
"""
LOG.debug("Running command: %s" % self._command)
cmd = self._command
if isinstance(cmd, str):
cmd = cmd.split()
if user != 'root':
# lower the privileges
try:
real = pwd.getpwnam(user)
os.setuid(real.pw_uid)
except Exception as e:
LOG.error("Error setting privileges for user '%s': %s"
% (user, e))
# 126: command invoked cannot be executed
self._status = 126
return
cmd = ['su', user, '-c', self._command]
subproc = subprocess.Popen(cmd, stdout=subprocess.PIPE,
stderr=subprocess.PIPE, cwd=cwd, env=env)
output = subproc.communicate()
@ -576,6 +560,7 @@ class PackagesHandler(object):
* if a version array is supplied, choose the highest version from the
array and follow same logic for version string above
"""
cmd = CommandRunner("which yum").run()
if cmd.status == 1:
# yum not available, use DNF if available

View File

@ -29,7 +29,7 @@ from heat_cfntools.cfntools import cfn_helper
def popen_root_calls(calls):
kwargs = {'env': None, 'cwd': None, 'stderr': -1, 'stdout': -1}
return [
mock.call(call.split(), **kwargs)
mock.call(['su', 'root', '-c', call], **kwargs)
for call in calls
]
@ -51,9 +51,9 @@ class TestCommandRunner(testtools.TestCase):
def test_command_runner(self):
def returns(*args, **kwargs):
if args[0][0] == '/bin/command1':
if args[0][3] == '/bin/command1':
return FakePOpen('All good')
elif args[0][0] == '/bin/command2':
elif args[0][3] == '/bin/command2':
return FakePOpen('Doing something', 'error', -1)
else:
raise Exception('This should never happen')
@ -73,53 +73,13 @@ class TestCommandRunner(testtools.TestCase):
calls = popen_root_calls(['/bin/command1', '/bin/command2'])
mock_popen.assert_has_calls(calls)
def test_runner_runs_command_as_list(self):
with mock.patch('subprocess.Popen') as mock_popen:
command = '/bin/command --option=value arg1 arg2'
expected_cmd = ['/bin/command', '--option=value', 'arg1', 'arg2']
cmd = cfn_helper.CommandRunner(command)
cmd.run()
self.assertTrue(mock_popen.called)
actual_cmd = mock_popen.call_args[0][0]
self.assertTrue(isinstance(actual_cmd, list))
self.assertItemsEqual(expected_cmd, actual_cmd)
@mock.patch.object(cfn_helper.pwd, 'getpwnam')
@mock.patch.object(cfn_helper.os, 'setuid')
def test_privileges_are_lowered_for_non_root_user(self, mock_setuid,
mock_getpwnam):
pw_entry = mock.MagicMock()
pw_entry.pw_uid = 1001
mock_getpwnam.return_value = pw_entry
with mock.patch('subprocess.Popen') as mock_popen:
command = '/bin/command --option=value arg1 arg2'
cmd = cfn_helper.CommandRunner(command)
cmd.run(user='nonroot')
mock_getpwnam.assert_called_once_with('nonroot')
mock_setuid.assert_called_once_with(1001)
self.assertTrue(mock_popen.called)
@mock.patch.object(cfn_helper.pwd, 'getpwnam')
@mock.patch.object(cfn_helper.os, 'setuid')
def test_run_returns_when_cannot_set_privileges(self, mock_setuid,
mock_getpwnam):
mock_setuid.side_effect = Exception('[Error 1] Permission Denied')
with mock.patch('subprocess.Popen') as mock_popen:
command = '/bin/command2'
cmd = cfn_helper.CommandRunner(command)
cmd.run(user='nonroot')
self.assertTrue(mock_getpwnam.called)
self.assertTrue(mock_setuid.called)
self.assertFalse(mock_popen.called)
self.assertEqual(126, cmd.status)
class TestPackages(testtools.TestCase):
def test_yum_install(self):
def returns(*args, **kwargs):
if (args[0][0] == 'rpm' and args[0][1] == '-q'):
if args[0][3].startswith('rpm -q '):
return FakePOpen(returncode=1)
else:
return FakePOpen(returncode=0)
@ -146,8 +106,8 @@ class TestPackages(testtools.TestCase):
def test_dnf_install_yum_unavailable(self):
def returns(*args, **kwargs):
if ((args[0][0] == 'rpm' and args[0][1] == '-q')
or (args[0][0] == 'which' and args[0][1] == 'yum')):
if args[0][3].startswith('rpm -q ') \
or args[0][3] == 'which yum':
return FakePOpen(returncode=1)
else:
return FakePOpen(returncode=0)
@ -174,7 +134,7 @@ class TestPackages(testtools.TestCase):
def test_dnf_install(self):
def returns(*args, **kwargs):
if (args[0][0] == 'rpm' and args[0][1] == '-q'):
if args[0][3].startswith('rpm -q '):
return FakePOpen(returncode=1)
else:
return FakePOpen(returncode=0)
@ -201,7 +161,7 @@ class TestPackages(testtools.TestCase):
def test_zypper_install(self):
def returns(*args, **kwargs):
if (args[0][0] == 'rpm' and args[0][1] == '-q'):
if args[0][3].startswith('rpm -q '):
return FakePOpen(returncode=1)
else:
return FakePOpen(returncode=0)