diff --git a/nova/image/format_inspector.py b/nova/image/format_inspector.py index 268c98b99cb..8e57d7ed2c4 100644 --- a/nova/image/format_inspector.py +++ b/nova/image/format_inspector.py @@ -368,6 +368,23 @@ def safety_check(self): not self.has_unknown_features) +class QEDInspector(FileInspector): + def __init__(self, tracing=False): + super().__init__(tracing) + self.new_region('header', CaptureRegion(0, 512)) + + @property + def format_match(self): + if not self.region('header').complete: + return False + return self.region('header').data.startswith(b'QED\x00') + + def safety_check(self): + # QED format is not supported by anyone, but we want to detect it + # and mark it as just always unsafe. + return False + + # The VHD (or VPC as QEMU calls it) format consists of a big-endian # 512-byte "footer" at the beginning of the file with various # information, most of which does not matter to us: @@ -871,19 +888,52 @@ def close(self): self._source.close() +ALL_FORMATS = { + 'raw': FileInspector, + 'qcow2': QcowInspector, + 'vhd': VHDInspector, + 'vhdx': VHDXInspector, + 'vmdk': VMDKInspector, + 'vdi': VDIInspector, + 'qed': QEDInspector, +} + + def get_inspector(format_name): """Returns a FormatInspector class based on the given name. :param format_name: The name of the disk_format (raw, qcow2, etc). :returns: A FormatInspector or None if unsupported. """ - formats = { - 'raw': FileInspector, - 'qcow2': QcowInspector, - 'vhd': VHDInspector, - 'vhdx': VHDXInspector, - 'vmdk': VMDKInspector, - 'vdi': VDIInspector, - } - - return formats.get(format_name) + + return ALL_FORMATS.get(format_name) + + +def detect_file_format(filename): + """Attempts to detect the format of a file. + + This runs through a file one time, running all the known inspectors in + parallel. It stops reading the file once one of them matches or all of + them are sure they don't match. + + Returns the FileInspector that matched, if any. None if 'raw'. + """ + inspectors = {k: v() for k, v in ALL_FORMATS.items()} + with open(filename, 'rb') as f: + for chunk in chunked_reader(f): + for format, inspector in list(inspectors.items()): + try: + inspector.eat_chunk(chunk) + except ImageFormatError: + # No match, so stop considering this format + inspectors.pop(format) + continue + if (inspector.format_match and inspector.complete and + format != 'raw'): + # First complete match (other than raw) wins + return inspector + if all(i.complete for i in inspectors.values()): + # If all the inspectors are sure they are not a match, avoid + # reading to the end of the file to settle on 'raw'. + break + return inspectors['raw'] diff --git a/nova/tests/unit/virt/libvirt/test_driver.py b/nova/tests/unit/virt/libvirt/test_driver.py index 4ae3b7a7ab6..9c37b2977bb 100644 --- a/nova/tests/unit/virt/libvirt/test_driver.py +++ b/nova/tests/unit/virt/libvirt/test_driver.py @@ -14477,10 +14477,11 @@ def test_create_images_and_backing_images_exist( '/fake/instance/dir', disk_info) self.assertFalse(mock_fetch_image.called) + @mock.patch('nova.image.format_inspector.detect_file_format') @mock.patch('nova.privsep.path.utime') @mock.patch('nova.virt.libvirt.utils.create_image') def test_create_images_and_backing_ephemeral_gets_created( - self, mock_create_cow_image, mock_utime): + self, mock_create_cow_image, mock_utime, mock_detect): drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False) base_dir = os.path.join(CONF.instances_path, @@ -16220,11 +16221,13 @@ def test_create_ephemeral_specified_fs(self, fake_mkfs): fake_mkfs.assert_has_calls([mock.call('ext4', '/dev/something', 'myVol')]) + @mock.patch('nova.image.format_inspector.detect_file_format') @mock.patch('nova.privsep.path.utime') @mock.patch('nova.virt.libvirt.utils.fetch_image') @mock.patch('nova.virt.libvirt.utils.create_image') def test_create_ephemeral_specified_fs_not_valid( - self, mock_create_cow_image, mock_fetch_image, mock_utime): + self, mock_create_cow_image, mock_fetch_image, mock_utime, + mock_detect): CONF.set_override('default_ephemeral_format', 'ext4') ephemerals = [{'device_type': 'disk', 'disk_bus': 'virtio', diff --git a/nova/tests/unit/virt/libvirt/test_imagebackend.py b/nova/tests/unit/virt/libvirt/test_imagebackend.py index 0dc1009c920..853c5a200c8 100644 --- a/nova/tests/unit/virt/libvirt/test_imagebackend.py +++ b/nova/tests/unit/virt/libvirt/test_imagebackend.py @@ -524,13 +524,15 @@ def test_cache_template_exists(self, mock_exists): mock_exists.assert_has_calls(exist_calls) + @mock.patch('nova.image.format_inspector.detect_file_format') @mock.patch.object(imagebackend.utils, 'synchronized') @mock.patch('nova.virt.libvirt.utils.create_image') @mock.patch.object(os.path, 'exists', side_effect=[]) @mock.patch.object(imagebackend.Image, 'verify_base_size') @mock.patch('nova.privsep.path.utime') def test_create_image( - self, mock_utime, mock_verify, mock_exist, mock_create, mock_sync + self, mock_utime, mock_verify, mock_exist, mock_create, mock_sync, + mock_detect_format ): mock_sync.side_effect = lambda *a, **kw: self._fake_deco fn = mock.MagicMock() @@ -551,7 +553,10 @@ def test_create_image( mock_exist.assert_has_calls(exist_calls) self.assertTrue(mock_sync.called) mock_utime.assert_called() + mock_detect_format.assert_called_once() + mock_detect_format.return_value.safety_check.assert_called_once_with() + @mock.patch('nova.image.format_inspector.detect_file_format') @mock.patch.object(imagebackend.utils, 'synchronized') @mock.patch('nova.virt.libvirt.utils.create_image') @mock.patch.object(imagebackend.disk, 'extend') @@ -559,7 +564,8 @@ def test_create_image( @mock.patch.object(imagebackend.Qcow2, 'get_disk_size') @mock.patch('nova.privsep.path.utime') def test_create_image_too_small(self, mock_utime, mock_get, mock_exist, - mock_extend, mock_create, mock_sync): + mock_extend, mock_create, mock_sync, + mock_detect_format): mock_sync.side_effect = lambda *a, **kw: self._fake_deco mock_get.return_value = self.SIZE fn = mock.MagicMock() @@ -576,7 +582,9 @@ def test_create_image_too_small(self, mock_utime, mock_get, mock_exist, self.assertTrue(mock_sync.called) self.assertFalse(mock_create.called) self.assertFalse(mock_extend.called) + mock_detect_format.assert_called_once() + @mock.patch('nova.image.format_inspector.detect_file_format') @mock.patch.object(imagebackend.utils, 'synchronized') @mock.patch('nova.virt.libvirt.utils.create_image') @mock.patch('nova.virt.libvirt.utils.get_disk_backing_file') @@ -588,7 +596,8 @@ def test_create_image_too_small(self, mock_utime, mock_get, mock_exist, def test_generate_resized_backing_files(self, mock_utime, mock_copy, mock_verify, mock_exist, mock_extend, mock_get, - mock_create, mock_sync): + mock_create, mock_sync, + mock_detect_format): mock_sync.side_effect = lambda *a, **kw: self._fake_deco mock_get.return_value = self.QCOW2_BASE fn = mock.MagicMock() @@ -615,7 +624,9 @@ def test_generate_resized_backing_files(self, mock_utime, mock_copy, self.assertTrue(mock_sync.called) self.assertFalse(mock_create.called) mock_utime.assert_called() + mock_detect_format.assert_called_once() + @mock.patch('nova.image.format_inspector.detect_file_format') @mock.patch.object(imagebackend.utils, 'synchronized') @mock.patch('nova.virt.libvirt.utils.create_image') @mock.patch('nova.virt.libvirt.utils.get_disk_backing_file') @@ -626,7 +637,8 @@ def test_generate_resized_backing_files(self, mock_utime, mock_copy, def test_qcow2_exists_and_has_no_backing_file(self, mock_utime, mock_verify, mock_exist, mock_extend, mock_get, - mock_create, mock_sync): + mock_create, mock_sync, + mock_detect_format): mock_sync.side_effect = lambda *a, **kw: self._fake_deco mock_get.return_value = None fn = mock.MagicMock() @@ -647,6 +659,31 @@ def test_qcow2_exists_and_has_no_backing_file(self, mock_utime, self.assertTrue(mock_sync.called) self.assertFalse(mock_create.called) self.assertFalse(mock_extend.called) + mock_detect_format.assert_called_once() + + @mock.patch('nova.image.format_inspector.detect_file_format') + @mock.patch.object(imagebackend.utils, 'synchronized') + @mock.patch('nova.virt.libvirt.utils.create_image') + @mock.patch('nova.virt.libvirt.utils.get_disk_backing_file') + @mock.patch.object(imagebackend.disk, 'extend') + @mock.patch.object(os.path, 'exists', side_effect=[]) + @mock.patch.object(imagebackend.Image, 'verify_base_size') + def test_qcow2_exists_and_fails_safety_check(self, + mock_verify, mock_exist, + mock_extend, mock_get, + mock_create, mock_sync, + mock_detect_format): + mock_detect_format.return_value.safety_check.return_value = False + mock_sync.side_effect = lambda *a, **kw: self._fake_deco + mock_get.return_value = None + fn = mock.MagicMock() + mock_exist.side_effect = [False, True, False, True, True] + image = self.image_class(self.INSTANCE, self.NAME) + + self.assertRaises(exception.InvalidDiskInfo, + image.create_image, fn, self.TEMPLATE_PATH, + self.SIZE) + mock_verify.assert_not_called() def test_resolve_driver_format(self): image = self.image_class(self.INSTANCE, self.NAME) diff --git a/nova/tests/unit/virt/libvirt/test_utils.py b/nova/tests/unit/virt/libvirt/test_utils.py index a62f9afd8cb..2b7bfb1a0f4 100644 --- a/nova/tests/unit/virt/libvirt/test_utils.py +++ b/nova/tests/unit/virt/libvirt/test_utils.py @@ -107,16 +107,29 @@ def test_valid_hostname_bad(self): @mock.patch('tempfile.NamedTemporaryFile') @mock.patch('oslo_concurrency.processutils.execute') @mock.patch('nova.virt.images.qemu_img_info') + @mock.patch('nova.image.format_inspector.detect_file_format') def _test_create_image( - self, path, disk_format, disk_size, mock_info, mock_execute, - mock_ntf, backing_file=None, encryption=None + self, path, disk_format, disk_size, mock_detect, mock_info, + mock_execute, mock_ntf, backing_file=None, encryption=None, + safety_check=True ): + if isinstance(backing_file, dict): + backing_info = backing_file + backing_file = backing_info.pop('file', None) + else: + backing_info = {} + backing_backing_file = backing_info.pop('backing_file', None) + mock_info.return_value = mock.Mock( file_format=mock.sentinel.backing_fmt, cluster_size=mock.sentinel.cluster_size, + backing_file=backing_backing_file, + format_specific=backing_info, ) fh = mock_ntf.return_value.__enter__.return_value + mock_detect.return_value.safety_check.return_value = safety_check + libvirt_utils.create_image( path, disk_format, disk_size, backing_file=backing_file, encryption=encryption, @@ -130,7 +143,7 @@ def _test_create_image( mock_info.assert_called_once_with(backing_file) cow_opts = [ '-o', - f'backing_file={mock.sentinel.backing_file},' + f'backing_file={backing_file},' f'backing_fmt={mock.sentinel.backing_fmt},' f'cluster_size={mock.sentinel.cluster_size}', ] @@ -166,6 +179,8 @@ def _test_create_image( expected_args += (disk_size,) self.assertEqual([(expected_args,)], mock_execute.call_args_list) + if backing_file: + mock_detect.return_value.safety_check.assert_called_once_with() def test_create_image_raw(self): self._test_create_image('/some/path', 'raw', '10G') @@ -181,6 +196,25 @@ def test_create_image_backing_file(self): backing_file=mock.sentinel.backing_file, ) + def test_create_image_base_has_backing_file(self): + self.assertRaises( + exception.InvalidDiskInfo, + self._test_create_image, + '/some/stuff', 'qcow2', '1234567891234', + backing_file={'file': mock.sentinel.backing_file, + 'backing_file': mock.sentinel.backing_backing_file}, + ) + + def test_create_image_base_has_data_file(self): + self.assertRaises( + exception.InvalidDiskInfo, + self._test_create_image, + '/some/stuff', 'qcow2', '1234567891234', + backing_file={'file': mock.sentinel.backing_file, + 'backing_file': mock.sentinel.backing_backing_file, + 'data': {'data-file': mock.sentinel.data_file}}, + ) + def test_create_image_size_none(self): self._test_create_image( '/some/stuff', 'qcow2', None, diff --git a/nova/virt/libvirt/imagebackend.py b/nova/virt/libvirt/imagebackend.py index 0a64ef43dd2..6ad794e4ae7 100644 --- a/nova/virt/libvirt/imagebackend.py +++ b/nova/virt/libvirt/imagebackend.py @@ -34,6 +34,7 @@ import nova.conf from nova import exception from nova.i18n import _ +from nova.image import format_inspector from nova.image import glance import nova.privsep.libvirt import nova.privsep.path @@ -661,6 +662,20 @@ def create_qcow2_image(base, target, size): if not os.path.exists(base): prepare_template(target=base, *args, **kwargs) + # NOTE(danms): We need to perform safety checks on the base image + # before we inspect it for other attributes. We do this each time + # because additional safety checks could have been added since we + # downloaded the image. + if not CONF.workarounds.disable_deep_image_inspection: + inspector = format_inspector.detect_file_format(base) + if not inspector.safety_check(): + LOG.warning('Base image %s failed safety check', base) + # NOTE(danms): This is the same exception as would be raised + # by qemu_img_info() if the disk format was unreadable or + # otherwise unsuitable. + raise exception.InvalidDiskInfo( + reason=_('Base image failed safety check')) + # NOTE(ankit): Update the mtime of the base file so the image # cache manager knows it is in use. _update_utime_ignore_eacces(base) diff --git a/nova/virt/libvirt/utils.py b/nova/virt/libvirt/utils.py index d9fe056ed0d..4a323158c1a 100644 --- a/nova/virt/libvirt/utils.py +++ b/nova/virt/libvirt/utils.py @@ -35,6 +35,7 @@ from nova import context as nova_context from nova import exception from nova.i18n import _ +from nova.image import format_inspector from nova import objects from nova.objects import fields as obj_fields import nova.privsep.fs @@ -147,7 +148,34 @@ def create_image( ] if backing_file: + # NOTE(danms): We need to perform safety checks on the base image + # before we inspect it for other attributes. We do this each time + # because additional safety checks could have been added since we + # downloaded the image. + if not CONF.workarounds.disable_deep_image_inspection: + inspector = format_inspector.detect_file_format(backing_file) + if not inspector.safety_check(): + LOG.warning('Base image %s failed safety check', backing_file) + # NOTE(danms): This is the same exception as would be raised + # by qemu_img_info() if the disk format was unreadable or + # otherwise unsuitable. + raise exception.InvalidDiskInfo( + reason=_('Base image failed safety check')) + base_details = images.qemu_img_info(backing_file) + if base_details.backing_file is not None: + LOG.warning('Base image %s failed safety check', backing_file) + raise exception.InvalidDiskInfo( + reason=_('Base image failed safety check')) + try: + data_file = base_details.format_specific['data']['data-file'] + except (KeyError, TypeError, AttributeError): + data_file = None + if data_file is not None: + LOG.warning('Base image %s failed safety check', backing_file) + raise exception.InvalidDiskInfo( + reason=_('Base image failed safety check')) + cow_opts = [ f'backing_file={backing_file}', f'backing_fmt={base_details.file_format}'