Bug fix to check the this CpuContext before using it

Author: chame1eon

CHANGELOG.md

@@ -1,5 +1,8 @@
 # jnitrace Change Log
 
+## 1.3.3
+- Bug fix - Checked whether the this context exists before using it
+
 ## 1.3.2
 - Bug fix - Use Process.findRangeByAddress instead of Process.findModuleByAddress for checking the validity of the stack pointer
 

jnitrace/src/jni/jni_env_interceptor.js

@@ -37,9 +37,13 @@ JNIEnvInterceptor.prototype.createJNIIntercept = function(id, methodAddr) {
 
   var nativeFunction = new NativeFunction(methodAddr, fridaRet, fridaArgs);
   var nativeCallback = new NativeCallback(function() {
-    var threadId = this.threadId;
+    var threadId = Process.getCurrentThreadId();
     var localArgs = [].slice.call(arguments);
     var jniEnv = self.threads.getJNIEnv(threadId);
+    var context = null;
+    if (this) {
+      context = this.context;
+    }
 
     localArgs[0] = jniEnv;
 
@@ -62,7 +66,7 @@ JNIEnvInterceptor.prototype.createJNIIntercept = function(id, methodAddr) {
       }
     }
 
-    self.transport.trace(method, localArgs, ret, this.context, add);
+    self.transport.trace(method, localArgs, ret, context, add);
 
     if (method.name === "GetMethodID" ||
         method.name === "GetStaticMethodID") {

jnitrace/src/transport/trace_transport.js

@@ -194,7 +194,7 @@ TraceTransport.prototype.trace = function(method, args, ret, context, add) {
 
   // verify that a backtrace is possible.
   // sometimes the NativeCallback provides erroneous CpuContexts
-  if (Process.findModuleByAddress(context.pc) &&
+  if (context && Process.findModuleByAddress(context.pc) &&
         Process.findRangeByAddress(context.sp)) {
     var bt = Thread.backtrace(context, Backtracer.FUZZY);
 

setup.py

@@ -8,7 +8,7 @@
 
 setup(
     name='jnitrace',
-    version='1.3.2',
+    version='1.3.3',
     description='A tool for tracing use of the JNI in Android apps',
     long_description=long_description,
     long_description_content_type='text/markdown',