diff --git a/mm/mmap.c b/mm/mmap.c
index 2d94235..9a796c4 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -334,8 +334,10 @@
 	struct vm_area_struct *vma = mm->mmap;
 	while (vma) {
 		struct anon_vma_chain *avc;
+		vma_lock_anon_vma(vma);
 		list_for_each_entry(avc, &vma->anon_vma_chain, same_vma)
 			anon_vma_interval_tree_verify(avc);
+		vma_unlock_anon_vma(vma);
 		vma = vma->vm_next;
 		i++;
 	}