Network response data crash issues.

[YYYSSSHHH]

Description information：
We find that mobile apps are prone to crashes due to a network issue, mainly because successful network API calls return unexpected or no data.
And we found that when this app's network returned data is null or some fields are null (JSON format) , or is empty, or the network request fails (status code is 404/503), the app has crashed.

We're doing a study. We use the fuzzing method to simulate the network response data. For example, when the app receives network API response data from the server or network, we will replace it with 404, null and random data.
#A very simple example:
normal data ：Value=”hello” -----fuzzing-----> simulated data ：Value=null or network request fails（404、503） or Value=”heee”(random data) or Value=""(empty) , etc.

Environment Info：
APK version 1.2.2 (27)
Simulator AndroidOS Version = “6.0.1”

crash information：
All of the following crash problems are caused by fuzzing data

one:

java.lang.RuntimeException: An error occurred while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:309)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.graphics.Bitmap.getHeight()' on a null object reference
at com.haringeymobile.ukweather.b.d.a(MiscMethods.java:86)
at com.haringeymobile.ukweather.weather.h$a.a(WeatherInformationDisplayer.java:251)
at com.haringeymobile.ukweather.weather.h$a.doInBackground(WeatherInformationDisplayer.java:231)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
... 4 more
java.lang.NullPointerException: Attempt to invoke virtual method 'int android.graphics.Bitmap.getHeight()' on a null object reference
at com.haringeymobile.ukweather.b.d.a(MiscMethods.java:86)
at com.haringeymobile.ukweather.weather.h$a.a(WeatherInformationDisplayer.java:251)
at com.haringeymobile.ukweather.weather.h$a.doInBackground(WeatherInformationDisplayer.java:231)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)

Two:

crashActivity=com.haringeymobile.ukweather.weather.WeatherInfoActivity

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.haringeymobile.ukweather/com.haringeymobile.ukweather.weather.WeatherInfoActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'long com.haringeymobile.ukweather.a.a.j.b()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2443)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2503)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1353)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5539)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:745)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:635)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'long com.haringeymobile.ukweather.a.a.j.b()' on a null object reference
at com.haringeymobile.ukweather.weather.c.a(WeatherCurrentInfoFragment.java:38)
at com.haringeymobile.ukweather.weather.f.b(WeatherInfoFragment.java:144)
at com.haringeymobile.ukweather.weather.c.d(WeatherCurrentInfoFragment.java:27)
at android.support.v4.b.l.k(Fragment.java:2193)
at android.support.v4.b.r.a(FragmentManager.java:1323)
at android.support.v4.b.r.y(FragmentManager.java:2323)
at android.support.v4.b.r.a(FragmentManager.java:2136)
at android.support.v4.b.r.b(FragmentManager.java:2092)
at android.support.v4.b.r.e(FragmentManager.java:1998)
at android.support.v4.b.o.n(FragmentController.java:388)
at android.support.v4.b.m.onStart(FragmentActivity.java:607)
at android.support.v7.app.c.onStart(AppCompatActivity.java:181)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1237)
at android.app.Activity.performStart(Activity.java:6296)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2406)
... 9 more
java.lang.NullPointerException: Attempt to invoke virtual method 'long com.haringeymobile.ukweather.a.a.j.b()' on a null object reference
at com.haringeymobile.ukweather.weather.c.a(WeatherCurrentInfoFragment.java:38)
at com.haringeymobile.ukweather.weather.f.b(WeatherInfoFragment.java:144)
at com.haringeymobile.ukweather.weather.c.d(WeatherCurrentInfoFragment.java:27)
at android.support.v4.b.l.k(Fragment.java:2193)
at android.support.v4.b.r.a(FragmentManager.java:1323)
at android.support.v4.b.r.y(FragmentManager.java:2323)
at android.support.v4.b.r.a(FragmentManager.java:2136)
at android.support.v4.b.r.b(FragmentManager.java:2092)
at android.support.v4.b.r.e(FragmentManager.java:1998)
at android.support.v4.b.o.n(FragmentController.java:388)
at android.support.v4.b.m.onStart(FragmentActivity.java:607)
at android.support.v7.app.c.onStart(AppCompatActivity.java:181)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1237)
at android.app.Activity.performStart(Activity.java:6296)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2406)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2503)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1353)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5539)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:745)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:635)

Finally:
The cause of the program crash may be that the network response data is not handled properly in the code. Such as, developers probably ignore the fact that data is null.
Although this kind of collapse is relatively rare, it is also worthy of attention.
If you have confirmed or fixed this problem, please give me a reply, this reply is very important to my research，thank you!

[HaringeyMobile]

Hi, When I started writing this code I didn't even think that some of the data fields (or even the entire message) coming from the server could be null -such possibility wasn't mentioned in the documentation, but in fact that happens from time to time. I had complaints from users about crashes like you describe in the past, and fixed some of them, but not all. So you are right about "the network response data not handled properly in the code". Good luck with your research. Regards Kestutis

…

On Tue, 25 Aug 2020 at 13:07, YYYSSSHHH ***@***.***> wrote: *Description information：* We find that mobile apps are prone to crashes due to a network issue, mainly because successful network API calls return unexpected or no data. And we found that when this app's network returned data is null or some fields are null (JSON format) , or is empty, or the network request fails (status code is 404/503), the app has crashed. We're doing a study. We use the fuzzing method to simulate the network response data. For example, when the app receives network API response data from the server or network, we will replace it with 404, null and random data. #A very simple example: normal data ：Value=”hello” -----fuzzing-----> simulated data ：Value=null or network request fails（404、503） or Value=”heee”(random data) or Value=""(empty) , etc. *Environment Info：* APK version 1.2.2 (27) Simulator AndroidOS Version = “6.0.1” *crash information：* All of the following crash problems are caused by fuzzing data one: java.lang.RuntimeException: An error occurred while executing doInBackground() at android.os.AsyncTask$3.done(AsyncTask.java:309) at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354) at java.util.concurrent.FutureTask.setException(FutureTask.java:223) at java.util.concurrent.FutureTask.run(FutureTask.java:242) at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588) at java.lang.Thread.run(Thread.java:818) *Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.graphics.Bitmap.getHeight()' on a null object reference* at com.haringeymobile.ukweather.b.d.a(MiscMethods.java:86) at com.haringeymobile.ukweather.weather.h$a.a(WeatherInformationDisplayer.java:251) at com.haringeymobile.ukweather.weather.h$a.doInBackground(WeatherInformationDisplayer.java:231) at android.os.AsyncTask$2.call(AsyncTask.java:295) at java.util.concurrent.FutureTask.run(FutureTask.java:237) ... 4 more java.lang.NullPointerException: Attempt to invoke virtual method 'int android.graphics.Bitmap.getHeight()' on a null object reference at com.haringeymobile.ukweather.b.d.a(MiscMethods.java:86) at com.haringeymobile.ukweather.weather.h$a.a(WeatherInformationDisplayer.java:251) at com.haringeymobile.ukweather.weather.h$a.doInBackground(WeatherInformationDisplayer.java:231) at android.os.AsyncTask$2.call(AsyncTask.java:295) at java.util.concurrent.FutureTask.run(FutureTask.java:237) at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588) at java.lang.Thread.run(Thread.java:818) Two: crashActivity=com.haringeymobile.ukweather.weather.WeatherInfoActivity java.lang.RuntimeException: Unable to start activity ComponentInfo{com.haringeymobile.ukweather/com.haringeymobile.ukweather.weather.WeatherInfoActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'long com.haringeymobile.ukweather.a.a.j.b()' on a null object reference at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2443) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2503) at android.app.ActivityThread.-wrap11(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1353) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5539) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:745) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:635) *Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'long com.haringeymobile.ukweather.a.a.j.b()' on a null object reference* at com.haringeymobile.ukweather.weather.c.a(WeatherCurrentInfoFragment.java:38) at com.haringeymobile.ukweather.weather.f.b(WeatherInfoFragment.java:144) at com.haringeymobile.ukweather.weather.c.d(WeatherCurrentInfoFragment.java:27) at android.support.v4.b.l.k(Fragment.java:2193) at android.support.v4.b.r.a(FragmentManager.java:1323) at android.support.v4.b.r.y(FragmentManager.java:2323) at android.support.v4.b.r.a(FragmentManager.java:2136) at android.support.v4.b.r.b(FragmentManager.java:2092) at android.support.v4.b.r.e(FragmentManager.java:1998) at android.support.v4.b.o.n(FragmentController.java:388) at android.support.v4.b.m.onStart(FragmentActivity.java:607) at android.support.v7.app.c.onStart(AppCompatActivity.java:181) at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1237) at android.app.Activity.performStart(Activity.java:6296) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2406) ... 9 more java.lang.NullPointerException: Attempt to invoke virtual method 'long com.haringeymobile.ukweather.a.a.j.b()' on a null object reference at com.haringeymobile.ukweather.weather.c.a(WeatherCurrentInfoFragment.java:38) at com.haringeymobile.ukweather.weather.f.b(WeatherInfoFragment.java:144) at com.haringeymobile.ukweather.weather.c.d(WeatherCurrentInfoFragment.java:27) at android.support.v4.b.l.k(Fragment.java:2193) at android.support.v4.b.r.a(FragmentManager.java:1323) at android.support.v4.b.r.y(FragmentManager.java:2323) at android.support.v4.b.r.a(FragmentManager.java:2136) at android.support.v4.b.r.b(FragmentManager.java:2092) at android.support.v4.b.r.e(FragmentManager.java:1998) at android.support.v4.b.o.n(FragmentController.java:388) at android.support.v4.b.m.onStart(FragmentActivity.java:607) at android.support.v7.app.c.onStart(AppCompatActivity.java:181) at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1237) at android.app.Activity.performStart(Activity.java:6296) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2406) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2503) at android.app.ActivityThread.-wrap11(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1353) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5539) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:745) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:635) *Finally:* The cause of the program crash may be that the network response data is not handled properly in the code. Such as, developers probably ignore the fact that data is null. Although this kind of collapse is relatively rare, it is also worthy of attention. If you have confirmed or fixed this problem, please give me a reply, this reply is very important to my research，thank you! — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#45>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AATD5SSZGKVNWFBSC7PIPLLSCOSPXANCNFSM4QKSIVQQ> .

[YYYSSSHHH]

Thanks for your reply very much ， How do you deal with "some of the data fields (or even the entire message) coming from the server could be null"? Do you judge the message in advance when you receive it ？