diff --git a/mm/hmm.c b/mm/hmm.c
index 2b05c53b82dc..2f1e98c6b644 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -670,7 +670,10 @@ static int hmm_do_fault(struct mm_struct *mm,
 		ret = handle_mm_fault(vma, addr, fault_flags, NULL);
 
 		if (ret & (VM_FAULT_COMPLETED | VM_FAULT_RETRY)) {
-			*hmm_vma_walk->locked = false;
+			if (hmm_vma_walk->locked)    /* needed by sparse */
+				*hmm_vma_walk->locked = false;
+			else
+				WARN_ON_ONCE(1);    /* broken fault handler */
 			return HMM_FAULT_UNLOCKED;
 		}