Ubuntu Cloud Archive

  1. Bug #2059809
  2. Comment #59

Comment 59 for bug 2059809

Revision history for this message
Dan Smith (danms) wrote : Re: Arbitrary file access through QCOW2 external data file

Earlier Martin said:

"The info command does not initiate a write operation"

If that's true then I think we're good to use info to look for and reject any children. If it's not, then either we need to cook up some other way to look at it (my format inspector code in glance may be an option) or get qemu-img fixed.

Based on all the back and forth, I'm not sure if the above statement is actually true, so please, someone clarify.

If it is true, then I don't see that the nova (or glance, as Brian said) stuff needs to change as we'd reject a qcow with data-file set before we do anything else. Brian, you're saying Cinder needs work purely because of a similar VHD-based approach, nothing to do with qcow right?

We could also extend my format inspector work in glance to detect things like data-file/backing-file in qcows and abort the upload mid-stream to avoid even allowing images with a backing file to be ingested into the system in the future.