check for infinitely expanding schemas

metosin · Jul 16, 2024 · 4d44b60 · 4d44b60
1 parent 0dd2e0d
commit 4d44b60
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/src/malli/core.cljc b/src/malli/core.cljc
@@ -264,7 +264,11 @@
 (defn- -lookup [?schema options]
   (let [registry (-registry options)]
     (or (mr/-schema registry ?schema)
-        (some-> registry (mr/-schema (c/type ?schema)) (-into-schema nil [?schema] options)))))
+        (when-some [p (some-> registry (mr/-schema (c/type ?schema)))]
+          (when (schema? ?schema)
+            (when (= p (-parent ?schema))
+              (-fail! ::infinitely-expanding-schema {:schema ?schema})))
+          (-into-schema p nil [?schema] options)))))
 
 (defn- -lookup! [?schema ?form f rec options]
   (or (and f (f ?schema) ?schema)

diff --git a/test/malli/core_test.cljc b/test/malli/core_test.cljc
@@ -3372,3 +3372,9 @@
                    :errors [{:path [::m/in :y], :in [:y], :schema y-schema, :value "2"}]}
                   explain))
     (is (form= y-schema (mu/get-in schema (-> explain :errors first :path))))))
+
+(deftest catch-infinitely-expanding-schema
+  (is (thrown-with-msg?
+        #?(:clj Exception, :cljs js/Error)
+        #":malli\.core/infinitely-expanding-schema"
+        (m/schema [(m/schema :any)]))))