diff --git a/[refs] b/[refs]
index 02ac73013c5e..1d5f61aa0acf 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3edbcff9bfe2ed632e518b3cfe807d062cee8269
+refs/heads/master: 51e4d5ab28c75d819b3840da11559ad5c1429135
diff --git a/trunk/arch/s390/kvm/kvm-s390.c b/trunk/arch/s390/kvm/kvm-s390.c
index 628494a43425..10bccd1f8aee 100644
--- a/trunk/arch/s390/kvm/kvm-s390.c
+++ b/trunk/arch/s390/kvm/kvm-s390.c
@@ -487,6 +487,12 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 
 	vcpu_load(vcpu);
 
+	/* verify, that memory has been registered */
+	if (!vcpu->kvm->arch.guest_memsize) {
+		vcpu_put(vcpu);
+		return -EINVAL;
+	}
+
 	if (vcpu->sigset_active)
 		sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);