filter cross context eval

src/runtime.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdlib.h>
 #include <limits>
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
@@ skipping 9764 matching lines @@
     // No callback set and code generation disallowed.
     return false;
   } else {
     // Callback set. Let it decide if code generation is allowed.
     VMState<EXTERNAL> state(isolate);
     return callback(v8::Utils::ToLocal(context));
   }
 }
 
 
+// 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);
   CONVERT_ARG_HANDLE_CHECKED(String, source, 0);
   CONVERT_BOOLEAN_ARG_CHECKED(function_literal_only, 1);
 
   // 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() &&
       !CodeGenerationFromStringsAllowed(isolate, context)) {
     Handle<Object> error_message =
         context->ErrorMessageForCodeGenerationFromStrings();
     return isolate->Throw(*isolate->factory()->NewEvalError(
         "code_gen_from_strings", HandleVector<Object>(&error_message, 1)));
   }
 
@@ skipping 5339 matching lines @@
   }
   return NULL;
 }
 
 
 const Runtime::Function* Runtime::FunctionForId(Runtime::FunctionId id) {
   return &(kIntrinsicFunctions[static_cast<int>(id)]);
 }
 
 } }  // namespace v8::internal