yahoo-eng-team team mailing list archive

[Matt Riedemann <mriedem.os@xxxxxxxxx>]

** Changed in: nova
       Status: New => Triaged

** Also affects: nova/ocata
   Importance: Undecided
       Status: New

** Also affects: nova/pike
   Importance: Undecided
       Status: New

** Also affects: nova/queens
   Importance: Undecided
       Status: New

** Changed in: nova/ocata
       Status: New => Triaged

** Changed in: nova/queens
       Status: New => Triaged

** Changed in: nova/pike
       Status: New => Triaged

** Changed in: nova/pike
   Importance: Undecided => High

** Changed in: nova
     Assignee: (unassigned) => Matt Riedemann (mriedem)

** Changed in: nova/queens
   Importance: Undecided => High

-- 
You received this bug notification because you are a member of Yahoo!
Engineering Team, which is subscribed to OpenStack Compute (nova).
https://bugs.launchpad.net/bugs/1739646

Title:
  Instance type with disk set to 0 can cause DoS

Status in OpenStack Compute (nova):
  Triaged
Status in OpenStack Compute (nova) ocata series:
  Triaged
Status in OpenStack Compute (nova) pike series:
  Triaged
Status in OpenStack Compute (nova) queens series:
  Triaged
Status in OpenStack Security Advisory:
  Incomplete

Bug description:
  In OpenStack at the moment, there is the ability to create instance
  types with disk size 0.  The API documentation states the following:

  "The size of the root disk that will be created in GiB. If 0 the root
  disk will be set to exactly the size of the image used to deploy the
  instance. However, in this case filter scheduler cannot select the
  compute host based on the virtual image size. Therefore, 0 should only
  be used for volume booted instances or for testing purposes."

  In a cloud environment where a deployer wants to offer boot-from-
  volume instances, those instance types will be there.  However, this
  means that a user can upload an image of 4TB and boot small instances
  where each one will have 4TB of storage, potentially exhausting the
  disks local storage (or Ceph cluster if using Ceph for ephemeral
  storage).

  I'm not sure if this is a security issue or it should be published as
  an advisory, but I believe there should be an option to disable the
  feature of booting an instance with the exact size of the image used
  so deployers have the ability/choice to provide boot-from-volume
  instance types.

  I can confirm this in our environment that if a customer creates an
  instance with 200GB of ephemeral disk space, they can take an image of
  it, then create an instance with that image on an instance type that
  has no ephemeral disk space and get 200GB of disk.

To manage notifications about this bug go to:
https://bugs.launchpad.net/nova/+bug/1739646/+subscriptions