Re: [RFC PATCH v1 01/10] KVM: SVM: Add KVM_SEV SEND_START command

Borislav Petkov
2019-04-29T16:36:11Z

On Mon, Apr 29, 2019 at 03:01:24PM +0000, Singh, Brijesh wrote:
> Practically I don't see any reason why caller would do that but
> theoretically it can. If we cache the len then we also need to consider
> adding another flag to hint whether userspace ever requested length.
> e.g an application can compute the length of session blob by looking at
> the API version and spec and may never query the length.
>
> > I mean I'm still thinking defensively here but maybe the only thing that
> > would happen here with a bigger buffer is if the kmalloc() would fail,
> > leading to eventual failure of the migration.
> >
> > If the code limits the allocation to some sane max length, the migration
> > won't fail even if userspace gives it too big values...

So what about this? Limiting to a sane length...

--
Regards/Gruss,
Boris.

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