filter cross context eval

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 7eb753ab1c9d36f6848efb21f6d7b4f83ae05fa6..0f8d79406739ac5d45479c398a24cfc06f78df3e 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -9782,6 +9782,59 @@ bool CodeGenerationFromStringsAllowed(Isolate* isolate,
 }
 
 
+// Walk up the stack expecting:
+//  - Runtime_CompileString
+//  - JSFunction callee (eval, Function constructor, etc)
+//  - call() (maybe)
+//  - apply() (maybe)
+//  - bind() (maybe)
+// - JSFunction caller (maybe)
+//
+// return true if the caller has the same security token as the callee
+// or if an exit frame was hit, in which case allow it through, as it could
+// have come through the api.
+static bool TokensMatchForCompileString(Isolate* isolate) {
+  MaybeHandle<JSFunction> callee;
+  bool exit_handled = true;
+  bool tokens_match = true;
+  bool done = false;
+  for (StackFrameIterator it(isolate); !it.done() && !done; it.Advance()) {
+    StackFrame* raw_frame = it.frame();
+    if (!raw_frame->is_java_script()) {
+      if (raw_frame->is_exit()) exit_handled = false;
+      continue;
+    }
+    JavaScriptFrame* outer_frame = JavaScriptFrame::cast(raw_frame);
+    List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
+    outer_frame->Summarize(&frames);
+    for (int i = frames.length() - 1; i >= 0 && !done; --i) {
+      FrameSummary& frame = frames[i];
+      Handle<JSFunction> fun = frame.function();
+      // Capture the callee function.
+      if (callee.is_null()) {
+        callee = fun;
+        exit_handled = true;
+        continue;
+      }
+      // Exit condition.
+      Handle<Context> context(callee.ToHandleChecked()->context());
+      if (!fun->context()->HasSameSecurityTokenAs(*context)) {
+        tokens_match = false;
+        done = true;
+        continue;
+      }
+      // Skip bound functions in correct origin.
+      if (fun->shared()->bound()) {
+        exit_handled = true;
+        continue;
+      }
+      done = true;
+    }
+  }
+  return !exit_handled || tokens_match;
+}
+
+
 RUNTIME_FUNCTION(Runtime_CompileString) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 2);
@@ -9791,6 +9844,11 @@ RUNTIME_FUNCTION(Runtime_CompileString) {
   // Extract native context.
   Handle<Context> context(isolate->context()->native_context());
 
+  // Filter cross security context calls.
+  if (!TokensMatchForCompileString(isolate)) {
+    return isolate->heap()->undefined_value();
+  }
+
   // Check if native context allows code generation from
   // strings. Throw an exception if it doesn't.
   if (context->allow_code_gen_from_strings()->IsFalse() &&