commit c9fa770b6eedcf0cfe05b2449423f5494eecfce0
author Dan Zimmerman <danzimm@fb.com> Fri Jan 31 13:35:12 2020 -0800
committer Calin Juravle <calin@google.com> Sat Feb 08 02:41:12 2020 +0000
tree 684657b011f8980da10cbdc89ca6288d933a2734
parent a7d98b9560166eddaeb78d0f19402ee80ec9df06

Introduce VMRuntime.isValidClassLoaderContext

In the PackageManager server we need to validate class loader contexts
that we receive from an untrusted process. In order to keep class loader
context parsing logic centralized within the runtime let's create an API
which returns whether or not the runtime can parse the encoded class
loader context.

Test: Build system image, open app using secondary dex
Test: atest atest com.android.server.pm.dex.DexManagerTests
Test: m test-art-host-gtest-class_loader_context_test
Change-Id: Ied676e3239f70a8ab9d066df79f377b7036b28b7

runtime/native/dalvik_system_VMRuntime.cc

diff --git a/runtime/native/dalvik_system_VMRuntime.cc b/runtime/native/dalvik_system_VMRuntime.cc
index a4dc042..dbfa2a8 100644
--- a/runtime/native/dalvik_system_VMRuntime.cc
+++ b/runtime/native/dalvik_system_VMRuntime.cc
@@ -34,6 +34,7 @@
 #include "base/enums.h"
 #include "base/sdk_version.h"
 #include "class_linker-inl.h"
+#include "class_loader_context.h"
 #include "common_throws.h"
 #include "debugger.h"
 #include "dex/class_accessor-inl.h"
@@ -767,6 +768,18 @@
   Runtime::Current()->GetClassLinker()->VisitClasses(&visitor);
 }
 
+static jboolean VMRuntime_isValidClassLoaderContext(JNIEnv* env,
+                                                    jclass klass ATTRIBUTE_UNUSED,
+                                                    jstring jencoded_class_loader_context) {
+  if (UNLIKELY(jencoded_class_loader_context == nullptr)) {
+    ScopedFastNativeObjectAccess soa(env);
+    ThrowNullPointerException("encoded_class_loader_context == null");
+    return false;
+  }
+  ScopedUtfChars encoded_class_loader_context(env, jencoded_class_loader_context);
+  return ClassLoaderContext::IsValidEncoding(encoded_class_loader_context.c_str());
+}
+
 static JNINativeMethod gMethods[] = {
   FAST_NATIVE_METHOD(VMRuntime, addressOf, "(Ljava/lang/Object;)J"),
   NATIVE_METHOD(VMRuntime, bootClassPath, "()Ljava/lang/String;"),
@@ -818,6 +831,7 @@
   NATIVE_METHOD(VMRuntime, setProcessDataDirectory, "(Ljava/lang/String;)V"),
   NATIVE_METHOD(VMRuntime, bootCompleted, "()V"),
   NATIVE_METHOD(VMRuntime, resetJitCounters, "()V"),
+  NATIVE_METHOD(VMRuntime, isValidClassLoaderContext, "(Ljava/lang/String;)Z"),
 };
 
 void register_dalvik_system_VMRuntime(JNIEnv* env) {