linux-kernel - Re: [PATCH v5 04/13] KVM: Introduce a new guest mapping API

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 25 Jan 2019 18:09:33 +0000
From:   "Raslan, KarimAllah" <karahmed@...zon.de>
To:     "konrad.wilk@...cle.com" <konrad.wilk@...cle.com>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "rkrcmar@...hat.com" <rkrcmar@...hat.com>,
        "pbonzini@...hat.com" <pbonzini@...hat.com>
Subject: Re: [PATCH v5 04/13] KVM: Introduce a new guest mapping API

On Wed, 2019-01-23 at 12:50 -0500, Konrad Rzeszutek Wilk wrote:
> > 
> > +	if (dirty)
> > +		kvm_release_pfn_dirty(map->pfn);
> > +	else
> > +		kvm_release_pfn_clean(map->pfn);
> > +	map->hva = NULL;
> 
> I keep on having this gnawing feeling that we MUST set map->page to
> NULL.
> 
> That is I can see how it is not needed if you are using 'map' and
> 'unmap' together - for that we are good. But what I am worried is that
> some one unmaps it .. and instead of checking map->hva they end up
> checking map->page and think the page is mapped.
> 
> Would you be OK adding that extra statement just as a fail-safe
> mechanism in case someones misues the APIs?

Good point, will do.



Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich
Ust-ID: DE 289 237 879
Eingetragen am Amtsgericht Charlottenburg HRB 149173 B