Re: QEMU "drive_init()" Disk Format Security Bypass

[Keir Fraser <keir.fraser@eu.citrix.com>]

On 8/5/08 18:12, "Daniel P. Berrange" <berrange@redhat.com> wrote:

>> Should we break all old installations by requiring everyone to specify
>> a format ?  Or should we break only some old installations by
>> retaining the current syntax to mean one thing or the other ?  Perhaps
>> we should attempt to guess according to the _filename_, which is
>> controlled by the host and thus safe.  Do users typically choose
>> filenames for cow images which are enough of a giveaway ?
> 
> Well, tap:XXX: style URLS already encode the format explicitly. So if
> we made QEMU understand that syntax too, then that gives admins the
> option to be secure, while keeping file: fas a legacy (unsecure) mode
> for compatability. This has the added advantage that it'd be the same
> syntax used for PV-on-HVM drivers, and avoids nasty guessing based on
> filename.

Yes, I think we should keep the existing syntax's existing semantics. Just
as qemu/kvm have done.

 -- Keir