diff options
Diffstat (limited to 'sys-cluster/nova/files/cve-2015-7548-stable-liberty-0002.patch')
| -rw-r--r-- | sys-cluster/nova/files/cve-2015-7548-stable-liberty-0002.patch | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/sys-cluster/nova/files/cve-2015-7548-stable-liberty-0002.patch b/sys-cluster/nova/files/cve-2015-7548-stable-liberty-0002.patch new file mode 100644 index 000000000000..2ffca9f9cf8a --- /dev/null +++ b/sys-cluster/nova/files/cve-2015-7548-stable-liberty-0002.patch @@ -0,0 +1,168 @@ +From 0e6b4a06ad72ac68ec41bab2063f8d167e8e277e Mon Sep 17 00:00:00 2001 +From: Matthew Booth <mbooth@redhat.com> +Date: Thu, 10 Dec 2015 16:34:19 +0000 +Subject: [PATCH 2/3] Fix format conversion in libvirt snapshot + +The libvirt driver was calling images.convert_image during snapshot to +convert snapshots to the intended output format. However, this +function does not take the input format as an argument, meaning it +implicitly does format detection. This opened an exploit for setups +using raw storage on the backend, including raw on filesystem, LVM, +and RBD (Ceph). An authenticated user could write a qcow2 header to +their instance's disk which specified an arbitrary backing file on the +host. When convert_image ran during snapshot, this would then write +the contents of the backing file to glance, which is then available to +the user. If the setup uses an LVM backend this conversion runs as +root, meaning the user can exfiltrate any file on the host, including +raw disks. + +This change adds an input format to convert_image. + +Partial-Bug: #1524274 + +Change-Id: If73e73718ecd5db262ed9904091024238f98dbc0 +(cherry picked from commit 840644d619e9560f205016eafc8799565ffd6d8c) +--- + nova/tests/unit/virt/libvirt/test_driver.py | 5 +++-- + nova/tests/unit/virt/libvirt/test_utils.py | 3 ++- + nova/virt/images.py | 26 ++++++++++++++++++++++++-- + nova/virt/libvirt/imagebackend.py | 19 ++++++++++++++----- + 4 files changed, 43 insertions(+), 10 deletions(-) + +diff --git a/nova/tests/unit/virt/libvirt/test_driver.py b/nova/tests/unit/virt/libvirt/test_driver.py +index 22ef56d..6fd8728 100644 +--- a/nova/tests/unit/virt/libvirt/test_driver.py ++++ b/nova/tests/unit/virt/libvirt/test_driver.py +@@ -14985,7 +14985,7 @@ class LibvirtVolumeSnapshotTestCase(test.NoDBTestCase): + self.mox.VerifyAll() + + +-def _fake_convert_image(source, dest, out_format, ++def _fake_convert_image(source, dest, in_format, out_format, + run_as_root=True): + libvirt_driver.libvirt_utils.files[dest] = '' + +@@ -15127,7 +15127,8 @@ class LVMSnapshotTests(_BaseSnapshotTests): + + mock_volume_info.assert_has_calls([mock.call('/dev/nova-vg/lv')]) + mock_convert_image.assert_called_once_with( +- '/dev/nova-vg/lv', mock.ANY, disk_format, run_as_root=True) ++ '/dev/nova-vg/lv', mock.ANY, 'raw', disk_format, ++ run_as_root=True) + + def test_raw(self): + self._test_lvm_snapshot('raw') +diff --git a/nova/tests/unit/virt/libvirt/test_utils.py b/nova/tests/unit/virt/libvirt/test_utils.py +index 6773bea..6f75a92 100644 +--- a/nova/tests/unit/virt/libvirt/test_utils.py ++++ b/nova/tests/unit/virt/libvirt/test_utils.py +@@ -594,7 +594,8 @@ disk size: 4.4M + target = 't.qcow2' + self.executes = [] + expected_commands = [('qemu-img', 'convert', '-O', 'raw', +- 't.qcow2.part', 't.qcow2.converted'), ++ 't.qcow2.part', 't.qcow2.converted', ++ '-f', 'qcow2'), + ('rm', 't.qcow2.part'), + ('mv', 't.qcow2.converted', 't.qcow2')] + images.fetch_to_raw(context, image_id, target, user_id, project_id, +diff --git a/nova/virt/images.py b/nova/virt/images.py +index 5b9374b..e2b5b91 100644 +--- a/nova/virt/images.py ++++ b/nova/virt/images.py +@@ -66,9 +66,31 @@ def qemu_img_info(path): + return imageutils.QemuImgInfo(out) + + +-def convert_image(source, dest, out_format, run_as_root=False): ++def convert_image(source, dest, in_format, out_format, run_as_root=False): + """Convert image to other format.""" ++ if in_format is None: ++ raise RuntimeError("convert_image without input format is a security" ++ "risk") ++ _convert_image(source, dest, in_format, out_format, run_as_root) ++ ++ ++def convert_image_unsafe(source, dest, out_format, run_as_root=False): ++ """Convert image to other format, doing unsafe automatic input format ++ detection. Do not call this function. ++ """ ++ ++ # NOTE: there is only 1 caller of this function: ++ # imagebackend.Lvm.create_image. It is not easy to fix that without a ++ # larger refactor, so for the moment it has been manually audited and ++ # allowed to continue. Remove this function when Lvm.create_image has ++ # been fixed. ++ _convert_image(source, dest, None, out_format, run_as_root) ++ ++ ++def _convert_image(source, dest, in_format, out_format, run_as_root): + cmd = ('qemu-img', 'convert', '-O', out_format, source, dest) ++ if in_format is not None: ++ cmd = cmd + ('-f', in_format) + utils.execute(*cmd, run_as_root=run_as_root) + + +@@ -123,7 +145,7 @@ def fetch_to_raw(context, image_href, path, user_id, project_id, max_size=0): + staged = "%s.converted" % path + LOG.debug("%s was %s, converting to raw" % (image_href, fmt)) + with fileutils.remove_path_on_error(staged): +- convert_image(path_tmp, staged, 'raw') ++ convert_image(path_tmp, staged, fmt, 'raw') + os.unlink(path_tmp) + + data = qemu_img_info(staged) +diff --git a/nova/virt/libvirt/imagebackend.py b/nova/virt/libvirt/imagebackend.py +index 5e14f61..151ebc4 100644 +--- a/nova/virt/libvirt/imagebackend.py ++++ b/nova/virt/libvirt/imagebackend.py +@@ -477,7 +477,7 @@ class Raw(Image): + self.correct_format() + + def snapshot_extract(self, target, out_format): +- images.convert_image(self.path, target, out_format) ++ images.convert_image(self.path, target, self.driver_format, out_format) + + @staticmethod + def is_file_in_instance_path(): +@@ -631,7 +631,16 @@ class Lvm(Image): + size, sparse=self.sparse) + if self.ephemeral_key_uuid is not None: + encrypt_lvm_image() +- images.convert_image(base, self.path, 'raw', run_as_root=True) ++ # NOTE: by calling convert_image_unsafe here we're ++ # telling qemu-img convert to do format detection on the input, ++ # because we don't know what the format is. For example, ++ # we might have downloaded a qcow2 image, or created an ++ # ephemeral filesystem locally, we just don't know here. Having ++ # audited this, all current sources have been sanity checked, ++ # either because they're locally generated, or because they have ++ # come from images.fetch_to_raw. However, this is major code smell. ++ images.convert_image_unsafe(base, self.path, self.driver_format, ++ run_as_root=True) + if resize: + disk.resize2fs(self.path, run_as_root=True) + +@@ -678,8 +687,8 @@ class Lvm(Image): + lvm.remove_volumes([self.lv_path]) + + def snapshot_extract(self, target, out_format): +- images.convert_image(self.path, target, out_format, +- run_as_root=True) ++ images.convert_image(self.path, target, self.driver_format, ++ out_format, run_as_root=True) + + def get_model(self, connection): + return imgmodel.LocalBlockImage(self.path) +@@ -786,7 +795,7 @@ class Rbd(Image): + self.driver.resize(self.rbd_name, size) + + def snapshot_extract(self, target, out_format): +- images.convert_image(self.path, target, out_format) ++ images.convert_image(self.path, target, 'raw', out_format) + + @staticmethod + def is_shared_block_storage(): +-- +2.5.0 + |