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Commit 37f6a4e2 authored by Marcelo Tosatti's avatar Marcelo Tosatti Committed by Paolo Bonzini
Browse files

KVM: x86: handle invalid root_hpa everywhere 



Rom Freiman <rom@stratoscale.com> notes other code paths vulnerable to
bug fixed by 989c6b34.

Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent ab53f22e

arch/x86/kvm/mmu.c

+9 −0
Original line number Diff line number Diff line
@@ -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;

arch/x86/kvm/paging_tmpl.h

+8 −0
Original line number Diff line number Diff line
@@ -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;