Messages in this thread | | | Date | Thu, 28 Sep 2023 17:24:18 -0700 | Subject | Re: [PATCH v2 1/4] x86: KVM: SVM: always update the x2avic msr interception | From | Sean Christopherson <> |
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On Thu, Sep 28, 2023, Maxim Levitsky wrote: > The following problem exists since x2avic was enabled in the KVM: > > svm_set_x2apic_msr_interception is called to enable the interception of
Nit, svm_set_x2apic_msr_interception().
Definitely not worth another version though.
> the x2apic msrs. > > In particular it is called at the moment the guest resets its apic. > > Assuming that the guest's apic was in x2apic mode, the reset will bring > it back to the xapic mode. > > The svm_set_x2apic_msr_interception however has an erroneous check for > '!apic_x2apic_mode()' which prevents it from doing anything in this case. > > As a result of this, all x2apic msrs are left unintercepted, and that > exposes the bare metal x2apic (if enabled) to the guest. > Oops. > > Remove the erroneous '!apic_x2apic_mode()' check to fix that. > > This fixes CVE-2023-5090 > > Fixes: 4d1d7942e36a ("KVM: SVM: Introduce logic to (de)activate x2AVIC mode") > Cc: stable@vger.kernel.org > Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> > ---
Reviewed-by: Sean Christopherson <seanjc@google.com>
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