Merge pull request #810 from MarcMil/fix-type-refinement

BackwardsInfoflowProblem: Do not propagate taint on cast incompatible…

Author: StevenArzt

soot-infoflow/src/soot/jimple/infoflow/problems/BackwardsInfoflowProblem.java

@@ -371,6 +371,17 @@ else if (aliasing.mayAlias(leftVal, sourceBase)) {
 
 								AccessPath newAp = manager.getAccessPathFactory().copyWithNewValue(ap, rightVal,
 										rightType, cutFirstField);
+								if (rightOp instanceof CastExpr) {
+									Type castObjType = newAp.getBaseType();
+									Type castToType = rightOp.getType();
+									if (castObjType instanceof ArrayType && castToType instanceof ArrayType) {
+										ArrayType acastObjType = (ArrayType) castObjType;
+										ArrayType acastToType = (ArrayType) castToType;
+										if (acastObjType.numDimensions != acastToType.numDimensions)
+											// Cast incompatible
+											continue;
+									}
+								}
 								Abstraction newAbs = source.deriveNewAbstraction(newAp, assignStmt);
 								if (newAbs != null) {
 									if (rightVal instanceof StaticFieldRef && manager.getConfig()

soot-infoflow/test/soot/jimple/infoflow/test/TypeTestCode.java

@@ -355,6 +355,8 @@ public void fieldIncompatibleCastAndAliasTest() {
 		cm.publish(x2.b.data);
 	}
 
+	// An ClassCastException is happening: class [Ljava.lang.Object; cannot be cast
+	// to class [[Ljava.lang.String; ([Ljava.lang.Object; and [[Ljava.lang.String
 	public void twoDimensionArrayTest() {
 		String[] x = new String[1];
 		Object y = x;

soot-infoflow/test/soot/jimple/infoflow/test/junit/TypeTests.java

@@ -233,8 +233,10 @@ public void twoDimensionArrayTest() {
 		IInfoflow infoflow = initInfoflow();
 		List<String> epoints = new ArrayList<String>();
 		epoints.add("<soot.jimple.infoflow.test.TypeTestCode: void twoDimensionArrayTest()>");
+		// An ClassCastException is happening: class [Ljava.lang.Object; cannot be cast
+		// to class [[Ljava.lang.String; ([Ljava.lang.Object; and [[Ljava.lang.String
 		infoflow.computeInfoflow(appPath, libPath, epoints, sources, sinks);
-		checkInfoflow(infoflow, 1);
+		negativeCheckInfoflow(infoflow);
 	}
 
 	@Test(timeout = 300000)