Index: sys/arm64/arm64/pmap.c
===================================================================
--- sys/arm64/arm64/pmap.c
+++ sys/arm64/arm64/pmap.c
@@ -5138,6 +5138,8 @@
 			}
 		}
 		pte = pmap_pte(pmap, pv->pv_va, &lvl);
+		KASSERT(pte != NULL,
+		    ("%s: no pv page table entry found", __func__));
 		KASSERT(lvl == 3,
 		    ("pmap_page_test_mappings: Invalid level %d", lvl));
 		mask = 0;
@@ -5173,6 +5175,8 @@
 				}
 			}
 			pte = pmap_pte(pmap, pv->pv_va, &lvl);
+			KASSERT(pte != NULL,
+			    ("%s: no pvh page table entry found", __func__));
 			KASSERT(lvl == 2,
 			    ("pmap_page_test_mappings: Invalid level %d", lvl));
 			mask = 0;
@@ -5294,6 +5298,8 @@
 		}
 		va = pv->pv_va;
 		pte = pmap_pte(pmap, va, &lvl);
+		KASSERT(pte != NULL,
+		    ("%s: no page table entry found", __func__));
 		if ((pmap_load(pte) & ATTR_SW_DBM) != 0)
 			(void)pmap_demote_l2_locked(pmap, pte, va, &lock);
 		KASSERT(lock == VM_PAGE_TO_PV_LIST_LOCK(m),
@@ -5317,6 +5323,8 @@
 			}
 		}
 		pte = pmap_pte(pmap, pv->pv_va, &lvl);
+		KASSERT(pte != NULL,
+		    ("%s: no page table entry found", __func__));
 		oldpte = pmap_load(pte);
 		if ((oldpte & ATTR_SW_DBM) != 0) {
 			while (!atomic_fcmpset_64(pte, &oldpte,