Il 03/01/2014 20:09, Marcelo Tosatti ha scritto:
>
> Rom Freiman <rom@xxxxxxxxxxxxxxx> notes other code paths vulnerable to
> bug fixed by 989c6b34f6a9480e397b.
>
> Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index 31a5702..e50425d 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -2832,6 +2832,9 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level,
> bool ret = false;
> u64 spte = 0ull;
>
> + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
> + return false;
> +
> if (!page_fault_can_be_fast(error_code))
> return false;
>
> @@ -3227,6 +3230,9 @@ static u64 walk_shadow_page_get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr)
> struct kvm_shadow_walk_iterator iterator;
> u64 spte = 0ull;
>
> + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
> + return spte;
> +
> walk_shadow_page_lockless_begin(vcpu);
> for_each_shadow_entry_lockless(vcpu, addr, iterator, spte)
> if (!is_shadow_present_pte(spte))
> @@ -4513,6 +4519,9 @@ int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4])
> u64 spte;
> int nr_sptes = 0;
>
> + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
> + return nr_sptes;
> +
> walk_shadow_page_lockless_begin(vcpu);
> for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) {
> sptes[iterator.level-1] = spte;
> diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
> index ad75d77..cba218a 100644
> --- a/arch/x86/kvm/paging_tmpl.h
> +++ b/arch/x86/kvm/paging_tmpl.h
> @@ -569,6 +569,9 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
> if (FNAME(gpte_changed)(vcpu, gw, top_level))
> goto out_gpte_changed;
>
> + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
> + goto out_gpte_changed;
> +
> for (shadow_walk_init(&it, vcpu, addr);
> shadow_walk_okay(&it) && it.level > gw->level;
> shadow_walk_next(&it)) {
> @@ -820,6 +823,11 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
> */
> mmu_topup_memory_caches(vcpu);
>
> + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) {
> + WARN_ON(1);
> + return;
> + }
> +
> spin_lock(&vcpu->kvm->mmu_lock);
> for_each_shadow_entry(vcpu, gva, iterator) {
> level = iterator.level;
>
Applied to kvm/queue, thanks.
Paolo
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