Re: [Xen-devel] Fwd: Xen-4.1.6.1 backport for XSA156

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 20.11.15 at 16:03, <stefan.bader@xxxxxxxxxxxxx> wrote:
> I am currently trying to backport the changes of XSA156 back to Xen-4.1.x and 
> I
> am struggling with the VMX side. I did see the backports made for 4.2 and 3.4 
> on
> the security mailing list but I am not sure the 3.4 backport is not having the
> same issues (or similar ones).
> 
> Trying to write down my understanding of the changes: For the 3.4 backport 
> there
> are only changes to the toggles for debugging and the general trap mask. So 
> if I
> understand this right, before the change, TRAP_debug and TRAP_int3 were only
> handled in vmexit when a debugger was attached to the domain. Now, only
> TRAP_int3 will be toggled and TRAP_debug is always handled.

I've never looked at that 3.4 backport, but not changing the VMEXIT
handling certainly sounds wrong. I'll attach what I have done for 4.1.
Please report back any problems you encounter.

Jan

Attachment: CVE-2015-5307-xsa156.patch
Description: Text document

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