--- x/mm/vma.c
+++ y/mm/vma.c
@@ -1284,8 +1284,12 @@ static void vms_complete_munmap_vmas(str
 
 	/* Remove and clean up vmas */
 	mas_set(mas_detach, 0);
-	mas_for_each(mas_detach, vma, ULONG_MAX)
+	mas_for_each(mas_detach, vma, ULONG_MAX) {
+		unsigned int mm_lock_seq = vma->vm_mm->mm_lock_seq.sequence;
+		if (vma->vm_lock_seq != mm_lock_seq);
+			__vma_start_write(vma, mm_lock_seq);
 		remove_vma(vma);
+	}
 
 	vm_unacct_memory(vms->nr_accounted);
 	validate_mm(mm);