From db80927ea1977a845230a161df643b48fd1e1ea4 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 20 May 2019 11:55:36 +0200 Subject: KVM: nVMX: really fix the size checks on KVM_SET_NESTED_STATE The offset for reading the shadow VMCS is sizeof(*kvm_state)+VMCS12_SIZE, so the correct size must be that plus sizeof(*vmcs12). This could lead to KVM reading garbage data from userspace and not reporting an error, but is otherwise not sensitive. Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index f1a69117ac0f..2fd251ded754 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5427,7 +5427,7 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, vmcs12->vmcs_link_pointer != -1ull) { struct vmcs12 *shadow_vmcs12 = get_shadow_vmcs12(vcpu); - if (kvm_state->size < sizeof(*kvm_state) + 2 * sizeof(*vmcs12)) + if (kvm_state->size < sizeof(*kvm_state) + VMCS12_SIZE + sizeof(*vmcs12)) return -EINVAL; if (copy_from_user(shadow_vmcs12, -- cgit v1.2.3