DexPrinter : Exception in thread "main" java.util.ConcurrentModificationException

[louison]

Hi there, I'm currently experiencing a new error on multiple apks. These errors might be related to #999 and #1067.

This error comes up when trying to write apk classes using
PackManager.v().writeOutput(); with a loaded apk in Soot.

[Thread-20] ERROR heros.solver.CountingThreadPoolExecutor - Worker thread execution failed: null
java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:909)
	at java.util.ArrayList$Itr.next(ArrayList.java:859)
	at soot.toDex.DexPrinter.toMethods(DexPrinter.java:1077)
	at soot.toDex.DexPrinter.addAsClassDefItem(DexPrinter.java:656)
	at soot.toDex.DexPrinter.add(DexPrinter.java:1646)
	at soot.PackManager.writeClass(PackManager.java:1096)
	at soot.PackManager.lambda$writeOutput$1(PackManager.java:699)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Exception in thread "Thread-20" java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:909)
	at java.util.ArrayList$Itr.next(ArrayList.java:859)
	at soot.toDex.DexPrinter.toMethods(DexPrinter.java:1077)
	at soot.toDex.DexPrinter.addAsClassDefItem(DexPrinter.java:656)
	at soot.toDex.DexPrinter.add(DexPrinter.java:1646)
	at soot.PackManager.writeClass(PackManager.java:1096)
	at soot.PackManager.lambda$writeOutput$1(PackManager.java:699)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Exception in thread "main" java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:909)
	at java.util.ArrayList$Itr.next(ArrayList.java:859)
	at soot.toDex.DexPrinter.toMethods(DexPrinter.java:1077)
	at soot.toDex.DexPrinter.addAsClassDefItem(DexPrinter.java:656)
	at soot.toDex.DexPrinter.add(DexPrinter.java:1646)
	at soot.PackManager.writeClass(PackManager.java:1096)
	at soot.PackManager.lambda$writeOutput$1(PackManager.java:699)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

I think that the array of SootClass manipulated in the method DexPrinter.toMethod() might be modified when looping on it.

I don't know if it is directly related to Soot or to the Heroes lib.

Best,

Louison

[louison]

Here is an apk sample on which I experience the sample :
https://transfer.sh/5YqIp/com.cookware.worldcusinerecipes.apk

I'm using Soot 3.3.0 release with the develop branch of FlowDroid.

Please tell me if this issue should move to another repo such as FlowDroid or Heroes