Convert location meta data from pickle to string.

This patch fixes a potential security issue.
Fixes bug: 1213241

Change-Id: I6414d16ec72f26ceabbaf1364ad737f19f18381e

glance/db/sqlalchemy/migrate_repo/versions/029_location_meta_data_pickle_to_string.py

@@ -0,0 +1,75 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2013 Rackspace Hosting
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import json
+import pickle
+
+import sqlalchemy
+from sqlalchemy import MetaData, Table, Column
+from glance.db.sqlalchemy import models
+
+
+def upgrade(migrate_engine):
+    meta = sqlalchemy.schema.MetaData(migrate_engine)
+    image_locations = Table('image_locations', meta, autoload=True)
+    new_meta_data = Column('storage_meta_data', models.JSONEncodedDict,
+                           default={})
+    new_meta_data.create(image_locations)
+
+    noe = pickle.dumps({})
+    s = sqlalchemy.sql.select([image_locations]).\
+        where(image_locations.c.meta_data != noe)
+    conn = migrate_engine.connect()
+    res = conn.execute(s)
+
+    for row in res:
+        meta_data = row['meta_data']
+        x = pickle.loads(meta_data)
+        if x != {}:
+            stmt = image_locations.update().\
+                where(image_locations.c.id == row['id']).\
+                values(storage_meta_data=x)
+            conn.execute(stmt)
+    conn.close()
+    image_locations.columns['meta_data'].drop()
+    image_locations.columns['storage_meta_data'].alter(name='meta_data')
+
+
+def downgrade(migrate_engine):
+    meta = sqlalchemy.schema.MetaData(migrate_engine)
+    image_locations = Table('image_locations', meta, autoload=True)
+    old_meta_data = Column('old_meta_data', sqlalchemy.PickleType(),
+                           default={})
+    old_meta_data.create(image_locations)
+
+    noj = json.dumps({})
+    s = sqlalchemy.sql.select([image_locations]).\
+        where(image_locations.c.meta_data != noj)
+    conn = migrate_engine.connect()
+    res = conn.execute(s)
+
+    for row in res:
+        x = row['meta_data']
+        meta_data = json.loads(x)
+        if meta_data != {}:
+            stmt = image_locations.update().\
+                where(image_locations.c.id == row['id']).\
+                values(old_meta_data=meta_data)
+            conn.execute(stmt)
+    conn.close()
+    image_locations.columns['meta_data'].drop()
+    image_locations.columns['old_meta_data'].alter(name='meta_data')

glance/db/sqlalchemy/models.py

@@ -19,12 +19,14 @@
 """
 SQLAlchemy models for glance data
 """
+import json
 
 from sqlalchemy import Column, Integer, String, BigInteger
 from sqlalchemy.ext.compiler import compiles
 from sqlalchemy.ext.declarative import declarative_base
-from sqlalchemy import ForeignKey, DateTime, Boolean, Text, PickleType
+from sqlalchemy import ForeignKey, DateTime, Boolean, Text
 from sqlalchemy.orm import relationship, backref, object_mapper
+from sqlalchemy.types import TypeDecorator
 from sqlalchemy import Index, UniqueConstraint
 
 from glance.openstack.common import timeutils
@@ -38,6 +40,22 @@ def compile_big_int_sqlite(type_, compiler, **kw):
     return 'INTEGER'
 
 
+class JSONEncodedDict(TypeDecorator):
+    """Represents an immutable structure as a json-encoded string"""
+
+    impl = Text
+
+    def process_bind_param(self, value, dialect):
+        if value is not None:
+            value = json.dumps(value)
+        return value
+
+    def process_result_value(self, value, dialect):
+        if value is not None:
+            value = json.loads(value)
+        return value
+
+
 class ModelBase(object):
     """Base class for Nova and Glance Models"""
     __table_args__ = {'mysql_engine': 'InnoDB'}
@@ -169,7 +187,7 @@ class ImageLocation(BASE, ModelBase):
     image_id = Column(String(36), ForeignKey('images.id'), nullable=False)
     image = relationship(Image, backref=backref('locations'))
     value = Column(Text(), nullable=False)
-    meta_data = Column(PickleType(), default={})
+    meta_data = Column(JSONEncodedDict(), default={})
 
 
 class ImageMember(BASE, ModelBase):

glance/tests/unit/test_migrations.py

@@ -28,6 +28,7 @@ if possible.
 import commands
 import ConfigParser
 import datetime
+import json
 import os
 import pickle
 import urlparse
@@ -935,3 +936,60 @@ class TestMigrations(utils.BaseTestCase):
                       if idx.name == owner_index]
 
         self.assertNotIn((owner_index, columns), index_data)
+
+    def _pre_upgrade_029(self, engine):
+        image_locations = get_table(engine, 'image_locations')
+
+        meta_data = {'somelist': ['a', 'b', 'c'], 'avalue': 'hello',
+                     'adict': {}}
+
+        now = datetime.datetime.now()
+        image_id = 'fake_029_id'
+        url = 'file:///some/place/onthe/fs029'
+
+        images = get_table(engine, 'images')
+        temp = dict(deleted=False,
+                    created_at=now,
+                    updated_at=now,
+                    status='active',
+                    is_public=True,
+                    min_disk=0,
+                    min_ram=0,
+                    id=image_id)
+        images.insert().values(temp).execute()
+
+        pickle_md = pickle.dumps(meta_data)
+        temp = dict(deleted=False,
+                    created_at=now,
+                    updated_at=now,
+                    image_id=image_id,
+                    value=url,
+                    meta_data=pickle_md)
+        image_locations.insert().values(temp).execute()
+
+        return meta_data, image_id
+
+    def _check_029(self, engine, data):
+        meta_data = data[0]
+        image_id = data[1]
+        image_locations = get_table(engine, 'image_locations')
+
+        records = image_locations.select().\
+            where(image_locations.c.image_id == image_id).execute().fetchall()
+
+        for r in records:
+            d = json.loads(r['meta_data'])
+            self.assertEqual(d, meta_data)
+
+    def _post_downgrade_029(self, engine):
+        image_id = 'fake_029_id'
+
+        image_locations = get_table(engine, 'image_locations')
+
+        records = image_locations.select().\
+            where(image_locations.c.image_id == image_id).execute().fetchall()
+
+        for r in records:
+            md = r['meta_data']
+            d = pickle.loads(md)
+            self.assertEqual(type(d), dict)