--- x/mm/damon/dbgfs.c
+++ d/mm/damon/dbgfs.c
@@ -925,6 +925,7 @@ static int dbgfs_rm_context(char *name)
 			dbgfs_destroy_ctx(dbgfs_ctxs[i]);
 			continue;
 		}
+		WARN_ON_ONCE(dbgfs_nr_ctxs - 1 == j);
 		new_dirs[j] = dbgfs_dirs[i];
 		new_ctxs[j++] = dbgfs_ctxs[i];
 	}