| Message ID | 20221103141351.50662-3-mlevitsk@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | nSVM: Security and correctness fixes | expand |
On 03/11/2022 14:13, Maxim Levitsky wrote: > Make sure that KVM uses vmcb01 before freeing nested state, and warn if > that is not the case. > > This is a minimal fix for CVE-2022-3344 making the kernel print a warning > instead of a kernel panic. > > Cc: stable@vger.kernel.org > Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> > --- > arch/x86/kvm/svm/nested.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c > index b258d6988f5dde..b74da40c1fc40c 100644 > --- a/arch/x86/kvm/svm/nested.c > +++ b/arch/x86/kvm/svm/nested.c > @@ -1126,6 +1126,9 @@ void svm_free_nested(struct vcpu_svm *svm) > if (!svm->nested.initialized) > return; > > + if (WARN_ON_ONCE(svm->vmcb != svm->vmcb01.ptr)) > + svm_switch_vmcb(svm, &svm->vmcb01); > + > svm_vcpu_free_msrpm(svm->nested.msrpm); > svm->nested.msrpm = NULL; >
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index b258d6988f5dde..b74da40c1fc40c 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1126,6 +1126,9 @@ void svm_free_nested(struct vcpu_svm *svm) if (!svm->nested.initialized) return; + if (WARN_ON_ONCE(svm->vmcb != svm->vmcb01.ptr)) + svm_switch_vmcb(svm, &svm->vmcb01); + svm_vcpu_free_msrpm(svm->nested.msrpm); svm->nested.msrpm = NULL;
Make sure that KVM uses vmcb01 before freeing nested state, and warn if that is not the case. This is a minimal fix for CVE-2022-3344 making the kernel print a warning instead of a kernel panic. Cc: stable@vger.kernel.org Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> --- arch/x86/kvm/svm/nested.c | 3 +++ 1 file changed, 3 insertions(+)