diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index fc7de27960e73dab4ad96d8a6c987056a6b35cd2..6bb4f8b97b0ff54362c16522feb16abdbf917a93 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -928,6 +928,8 @@ static int kvm_s390_vm_start_migration(struct kvm *kvm)
 	/* mark all the pages in active slots as dirty */
 	for (slotnr = 0; slotnr < slots->used_slots; slotnr++) {
 		ms = slots->memslots + slotnr;
+		if (!ms->dirty_bitmap)
+			return -EINVAL;
 		/*
 		 * The second half of the bitmap is only used on x86,
 		 * and would be wasted otherwise, so we put it to good