Add access checks to Method and Field reflection.

Art side of this change. Has a corresponding libcore change.

Bug: 13620925
Change-Id: Ie67f802a2a400e8212b489b9a261b7028422d8ba

1 files changed, 35 insertions, 1 deletions

diff --git a/runtime/reflection.cc b/runtime/reflection.cc
index 7f39e70..b38f9b4 100644
--- a/runtime/reflection.cc
+++ b/runtime/reflection.cc
@@ -26,6 +26,7 @@
 #include "mirror/class-inl.h"
 #include "mirror/object_array.h"
 #include "mirror/object_array-inl.h"
+#include "nth_caller_visitor.h"
 #include "object_utils.h"
 #include "scoped_thread_state_change.h"
 #include "stack.h"
@@ -461,7 +462,7 @@ void InvokeWithShadowFrame(Thread* self, ShadowFrame* shadow_frame, uint16_t arg
 }
 
 jobject InvokeMethod(const ScopedObjectAccess& soa, jobject javaMethod,
-                     jobject javaReceiver, jobject javaArgs) {
+                     jobject javaReceiver, jobject javaArgs, bool accessible) {
   mirror::ArtMethod* m = mirror::ArtMethod::FromReflectedMethod(soa, javaMethod);
 
   mirror::Class* declaring_class = m->GetDeclaringClass();
@@ -499,6 +500,13 @@ jobject InvokeMethod(const ScopedObjectAccess& soa, jobject javaMethod,
     return NULL;
   }
 
+  // Validate access.
+  if (!accessible && !ValidateAccess(receiver, declaring_class, m->GetAccessFlags())) {
+    ThrowIllegalAccessException(nullptr, StringPrintf("Cannot access method: %s",
+                                                      PrettyMethod(m).c_str()).c_str());
+    return nullptr;
+  }
+
   // Invoke the method.
   JValue result;
   ArgArray arg_array(mh.GetShorty(), mh.GetShortyLength());
@@ -786,4 +794,30 @@ bool UnboxPrimitiveForResult(const ThrowLocation& throw_location, mirror::Object
   return UnboxPrimitive(&throw_location, o, dst_class, nullptr, unboxed_value);
 }
 
+bool ValidateAccess(mirror::Object* obj, mirror::Class* declaring_class, uint32_t access_flags) {
+  NthCallerVisitor visitor(Thread::Current(), 2);
+  visitor.WalkStack();
+  mirror::Class* caller_class = visitor.caller->GetDeclaringClass();
+
+  if (((access_flags & kAccPublic) && declaring_class->IsPublic()) ||
+      caller_class == declaring_class) {
+    return true;
+  }
+  if (access_flags & kAccPrivate) {
+    return false;
+  }
+  if (access_flags & kAccProtected) {
+    if (obj != nullptr && !obj->InstanceOf(caller_class) &&
+        !declaring_class->IsInSamePackage(caller_class)) {
+      return false;
+    } else if (declaring_class->IsAssignableFrom(caller_class)) {
+      return true;
+    }
+  }
+  if (!declaring_class->IsInSamePackage(caller_class)) {
+    return false;
+  }
+  return true;
+}
+
 }  // namespace art