commit 7da4c401614344e3274434a242b8231126b17981
author Andreas Gampe <agampe@google.com> Fri Aug 25 11:30:48 2017 -0700
committer Andreas Gampe <agampe@google.com> Wed Aug 30 11:35:19 2017 -0700
tree d06f9db0b42bb2d9f4886cf15f418af341dbe212
parent 8ef4b6121ea496d38c0b8aeebad3f1227f819b17

ART: Redo verification on field resolution failure

When compile-time verifying a field PUT and the field cannot be resolved,
the verification must be redone at runtime to ensure the field is not
final. Post an ACCESS_FIELD error.

An example is

  dex file A:
    class A {
      {
         B b = new B();
         B.final_field = 12345; // illegally modify final-after-new
       }
    }

  dex file B:
    class B {
      final int final_field = 0;
    }

when A is compiled without B.

Bug: 34966607
Bug: 64681719
Test: m test-art-host
Test: cts-tradefed run commandAndExit cts --m vm-tests-tf
Change-Id: Ibc14b003288f7acf3c865fcdef54a6d9ed4ac867

runtime/verifier/method_verifier.cc

diff --git a/runtime/verifier/method_verifier.cc b/runtime/verifier/method_verifier.cc
index 312d8df..cf4a6e0 100644
--- a/runtime/verifier/method_verifier.cc
+++ b/runtime/verifier/method_verifier.cc
@@ -4994,6 +4994,31 @@
       DCHECK(!can_load_classes_ || self_->IsExceptionPending());
       self_->ClearException();
     }
+  } else {
+    // If we don't have the field (it seems we failed resolution) and this is a PUT, we need to
+    // redo verification at runtime as the field may be final, unless the field id shows it's in
+    // the same class.
+    //
+    // For simplicity, it is OK to not distinguish compile-time vs runtime, and post this an
+    // ACCESS_FIELD failure at runtime. This has the same effect as NO_FIELD - punting the class
+    // to the access-checks interpreter.
+    //
+    // Note: see b/34966607. This and above may be changed in the future.
+    if (kAccType == FieldAccessType::kAccPut) {
+      const DexFile::FieldId& field_id = dex_file_->GetFieldId(field_idx);
+      const char* field_class_descriptor = dex_file_->GetFieldDeclaringClassDescriptor(field_id);
+      const RegType* field_class_type = &reg_types_.FromDescriptor(GetClassLoader(),
+                                                                   field_class_descriptor,
+                                                                   false);
+      if (!field_class_type->Equals(GetDeclaringClass())) {
+        Fail(VERIFY_ERROR_ACCESS_FIELD) << "could not check field put for final field modify of "
+                                        << field_class_descriptor
+                                        << "."
+                                        << dex_file_->GetFieldName(field_id)
+                                        << " from other class "
+                                        << GetDeclaringClass();
+      }
+    }
   }
   if (field_type == nullptr) {
     const DexFile::FieldId& field_id = dex_file_->GetFieldId(field_idx);