• S
    KVM: x86/mmu: Use -1 to flag an undefined spte in get_mmio_spte() · 2aa07893
    Sean Christopherson 提交于
    Return -1 from the get_walk() helpers if the shadow walk doesn't fill at
    least one spte, which can theoretically happen if the walk hits a
    not-present PDPTR.  Returning the root level in such a case will cause
    get_mmio_spte() to return garbage (uninitialized stack data).  In
    practice, such a scenario should be impossible as KVM shouldn't get a
    reserved-bit page fault with a not-present PDPTR.
    
    Note, using mmu->root_level in get_walk() is wrong for other reasons,
    too, but that's now a moot point.
    
    Fixes: 95fb5b02 ("kvm: x86/mmu: Support MMIO in the TDP MMU")
    Cc: Ben Gardon <bgardon@google.com>
    Cc: stable@vger.kernel.org
    Signed-off-by: NSean Christopherson <seanjc@google.com>
    Message-Id: <20201218003139.2167891-2-seanjc@google.com>
    Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
    2aa07893
tdp_mmu.c 31.4 KB
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