| Date | Fri, 18 Feb 2022 17:15:22 +0000 | From | Sean Christopherson <> | Subject | Re: [PATCH v2 04/18] KVM: x86/mmu: avoid NULL-pointer dereference on page freeing bugs |
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On Thu, Feb 17, 2022, Paolo Bonzini wrote: > WARN and bail if KVM attempts to free a root that isn't backed by a shadow > page. KVM allocates a bare page for "special" roots, e.g. when using PAE > paging or shadowing 2/3/4-level page tables with 4/5-level, and so root_hpa > will be valid but won't be backed by a shadow page. It's all too easy to > blindly call mmu_free_root_page() on root_hpa, be nice and WARN instead of > crashing KVM and possibly the kernel. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > ---
Reviewed-by: Sean Christopherson <seanjc@google.com>
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