diff options
| -rw-r--r-- | nova/tests/test_virt.py | 20 | ||||
| -rw-r--r-- | nova/virt/disk/api.py | 71 |
2 files changed, 66 insertions, 25 deletions
diff --git a/nova/tests/test_virt.py b/nova/tests/test_virt.py index 388f075af..c4aa828ad 100644 --- a/nova/tests/test_virt.py +++ b/nova/tests/test_virt.py @@ -15,8 +15,10 @@ # License for the specific language governing permissions and limitations # under the License. +from nova import exception from nova import flags from nova import test +from nova.virt.disk import api as disk_api from nova.virt import driver FLAGS = flags.FLAGS @@ -81,3 +83,21 @@ class TestVirtDriver(test.TestCase): 'swap_size': 0})) self.assertTrue(driver.swap_is_usable({'device_name': '/dev/sdb', 'swap_size': 1})) + + +class TestVirtDisk(test.TestCase): + def test_check_safe_path(self): + ret = disk_api._join_and_check_path_within_fs('/foo', 'etc', + 'something.conf') + self.assertEquals(ret, '/foo/etc/something.conf') + + def test_check_unsafe_path(self): + self.assertRaises(exception.Invalid, + disk_api._join_and_check_path_within_fs, + '/foo', 'etc/../../../something.conf') + + def test_inject_files_with_bad_path(self): + self.assertRaises(exception.Invalid, + disk_api._inject_file_into_fs, + '/tmp', '/etc/../../../../etc/passwd', + 'hax') diff --git a/nova/virt/disk/api.py b/nova/virt/disk/api.py index 42d9d9162..3e66cd2a7 100644 --- a/nova/virt/disk/api.py +++ b/nova/virt/disk/api.py @@ -311,20 +311,39 @@ def inject_data_into_fs(fs, key, net, metadata, admin_password, execute): _inject_admin_password_into_fs(admin_password, fs, execute=execute) -def _inject_file_into_fs(fs, path, contents): - absolute_path = os.path.join(fs, path.lstrip('/')) +def _join_and_check_path_within_fs(fs, *args): + '''os.path.join() with safety check for injected file paths. + + Join the supplied path components and make sure that the + resulting path we are injecting into is within the + mounted guest fs. Trying to be clever and specifying a + path with '..' in it will hit this safeguard. + ''' + absolute_path = os.path.realpath(os.path.join(fs, *args)) + if not absolute_path.startswith(os.path.realpath(fs) + '/'): + raise exception.Invalid(_('injected file path not valid')) + return absolute_path + + +def _inject_file_into_fs(fs, path, contents, append=False): + absolute_path = _join_and_check_path_within_fs(fs, path.lstrip('/')) + parent_dir = os.path.dirname(absolute_path) utils.execute('mkdir', '-p', parent_dir, run_as_root=True) - utils.execute('tee', absolute_path, process_input=contents, - run_as_root=True) + + args = [] + if append: + args.append('-a') + args.append(absolute_path) + + kwargs = dict(process_input=contents, run_as_root=True) + + utils.execute('tee', *args, **kwargs) def _inject_metadata_into_fs(metadata, fs, execute=None): - metadata_path = os.path.join(fs, "meta.js") metadata = dict([(m.key, m.value) for m in metadata]) - - utils.execute('tee', metadata_path, - process_input=jsonutils.dumps(metadata), run_as_root=True) + _inject_file_into_fs(fs, 'meta.js', jsonutils.dumps(metadata)) def _inject_key_into_fs(key, fs, execute=None): @@ -333,20 +352,22 @@ def _inject_key_into_fs(key, fs, execute=None): key is an ssh key string. fs is the path to the base of the filesystem into which to inject the key. """ - sshdir = os.path.join(fs, 'root', '.ssh') + sshdir = _join_and_check_path_within_fs(fs, 'root', '.ssh') utils.execute('mkdir', '-p', sshdir, run_as_root=True) utils.execute('chown', 'root', sshdir, run_as_root=True) utils.execute('chmod', '700', sshdir, run_as_root=True) - keyfile = os.path.join(sshdir, 'authorized_keys') - key_data = [ + + keyfile = os.path.join('root', '.ssh', 'authorized_keys') + + key_data = ''.join([ '\n', '# The following ssh key was injected by Nova', '\n', key.strip(), '\n', - ] - utils.execute('tee', '-a', keyfile, - process_input=''.join(key_data), run_as_root=True) + ]) + + _inject_file_into_fs(fs, keyfile, key_data, append=True) def _inject_net_into_fs(net, fs, execute=None): @@ -354,12 +375,13 @@ def _inject_net_into_fs(net, fs, execute=None): net is the contents of /etc/network/interfaces. """ - netdir = os.path.join(os.path.join(fs, 'etc'), 'network') + netdir = _join_and_check_path_within_fs(fs, 'etc', 'network') utils.execute('mkdir', '-p', netdir, run_as_root=True) utils.execute('chown', 'root:root', netdir, run_as_root=True) utils.execute('chmod', 755, netdir, run_as_root=True) - netfile = os.path.join(netdir, 'interfaces') - utils.execute('tee', netfile, process_input=net, run_as_root=True) + + netfile = os.path.join('etc', 'network', 'interfaces') + _inject_file_into_fs(fs, netfile, net) def _inject_admin_password_into_fs(admin_passwd, fs, execute=None): @@ -384,16 +406,15 @@ def _inject_admin_password_into_fs(admin_passwd, fs, execute=None): fd, tmp_shadow = tempfile.mkstemp() os.close(fd) - utils.execute('cp', os.path.join(fs, 'etc', 'passwd'), tmp_passwd, - run_as_root=True) - utils.execute('cp', os.path.join(fs, 'etc', 'shadow'), tmp_shadow, - run_as_root=True) + passwd_path = _join_and_check_path_within_fs(fs, 'etc', 'passwd') + shadow_path = _join_and_check_path_within_fs(fs, 'etc', 'shadow') + + utils.execute('cp', passwd_path, tmp_passwd, run_as_root=True) + utils.execute('cp', shadow_path, tmp_shadow, run_as_root=True) _set_passwd(admin_user, admin_passwd, tmp_passwd, tmp_shadow) - utils.execute('cp', tmp_passwd, os.path.join(fs, 'etc', 'passwd'), - run_as_root=True) + utils.execute('cp', tmp_passwd, passwd_path, run_as_root=True) os.unlink(tmp_passwd) - utils.execute('cp', tmp_shadow, os.path.join(fs, 'etc', 'shadow'), - run_as_root=True) + utils.execute('cp', tmp_shadow, shadow_path, run_as_root=True) os.unlink(tmp_shadow) |