Re: [Qemu-block] [PATCH for-2.3 1/1] block: New command line option --misc format-probing=off

[Paolo Bonzini]

On 23/03/2015 11:04, Markus Armbruster wrote:
> Probing is convenient, but probing untrusted raw images is insecure
> (CVE-2008-2004).  To avoid it, users should always specify raw format
> explicitly.  This isn't trivial, and even sophisticated users have
> gotten it wrong (libvirt CVE-2010-2237, CVE-2010-2238, CVE-2010-2239,
> plus more recent variations of the theme that didn't get CVEs because
> they were caught before they could hurt users).
> 
> Disabling probing entirely is a (hamfisted) way to ensure you always
> specify the format.
> 
> Instead of creating yet another simple option that doesn't work with
> -readconfig, create a "misc" option group and --misc command line
> option.  We're out of space in vm_config_groups[], so double it.
> 
> This will let us make existing miscellaneous non-QemeOpts options
> sugar for --misc, so they become available with -readconfig.  Left for
> another day.

Which exactly?  Could they fit into another scheme?  (See how
-mem-prealloc was replaced and generalized by memory-backend-* objects).

For example, -win2k-install-hack should really be an IDE disk property
that can be set with -global, and many other options could be machine or
display options.

I don't think it's the right solution.  Libvirt knows where to add a
format=raw option, and it can do it without waiting for QEMU to
implement this.  Direct command-line users are not going to use the
option anyway.

So for today we're 1-1 on NACKs. :D

Paolo