From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marc Zyngier <marc.zyngier@arm.com>
Subject: Re: [PATCH 1/2] kvm: whitelist struct kvm_vcpu_arch
Date: Thu, 26 Oct 2017 15:34:38 +0100
Message-ID: <86h8umasg1.fsf@arm.com>
References: <20171026134547.23664-1-pbonzini@redhat.com>
        <20171026134547.23664-2-pbonzini@redhat.com>
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Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        Christoffer Dall <christoffer.dall@linaro.org>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        Cornelia Huck <cohuck@redhat.com>,
        James Hogan <james.hogan@imgtec.com>,
        Paul Mackerras <paulus@samba.org>,
        kernel-hardening@lists.openwall.com,
        Kees Cook <keescook@chromium.org>,
        Christian Borntraeger <borntraeger@redhat.com>,
        Christoffer Dall <cdall@linaro.org>,
        Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20171026134547.23664-2-pbonzini@redhat.com> (Paolo Bonzini's
        message of "Thu, 26 Oct 2017 15:45:46 +0200")
Sender: linux-kernel-owner@vger.kernel.org
List-Id: kvm.vger.kernel.org

On Thu, Oct 26 2017 at  3:45:46 pm BST, Paolo Bonzini <pbonzini@redhat.com> wrote:
> On x86, ARM and s390, struct kvm_vcpu_arch has a usercopy region
> taht is read and written by the KVM_GET/SET_CPUID2 ioctls (x86)
> or KVM_GET/SET_ONE_REG (ARM/s390).  Without whitelisting the area,
> KVM is completely broken on those architectures with usercopy hardening
> enabled.
>
> For now, allow writing to the entire struct on all architectures.
> The KVM tree will not refine this to an architecture-specific
> subset of struct kvm_vcpu_arch.
>
> Cc: kernel-hardening@lists.openwall.com
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Christian Borntraeger <borntraeger@redhat.com>
> Cc: Christoffer Dall <cdall@linaro.org>
> Cc: Radim Krčmář <rkrcmar@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Acked-by: Marc Zyngier <marc.zyngier@arm.com>

	M.
-- 
Jazz is not dead. It just smells funny.