C++: First query with flow-paths through globals

cpp/ql/src/Security/CWE/CWE-134/UncontrolledFormatStringThroughGlobalVar.ql

@@ -3,7 +3,7 @@
  * @description Using externally-controlled format strings in
  *              printf-style functions can lead to buffer overflows
  *              or data representation problems.
- * @kind problem
+ * @kind path-problem
  * @problem.severity warning
  * @precision medium
  * @id cpp/tainted-format-string-through-global
@@ -16,15 +16,24 @@ import cpp
 import semmle.code.cpp.security.FunctionWithWrappers
 import semmle.code.cpp.security.Security
 import semmle.code.cpp.security.TaintTracking
+import TaintedWithPath
+
+class Configuration extends TaintTrackingConfiguration {
+  override predicate isSink(Element tainted) {
+    exists(PrintfLikeFunction printf | printf.outermostWrapperFunctionCall(tainted, _))
+  }
+
+  override predicate taintThroughGlobals() { any() }
+}
 
 from
-  PrintfLikeFunction printf, Expr arg, string printfFunction, Expr userValue, string cause,
-  string globalVar
+  PrintfLikeFunction printf, Expr arg, PathNode sourceNode, PathNode sinkNode,
+  string printfFunction, Expr userValue, string cause
 where
   printf.outermostWrapperFunctionCall(arg, printfFunction) and
-  not tainted(_, arg) and
-  taintedIncludingGlobalVars(userValue, arg, globalVar) and
+  not taintedWithoutGlobals(arg) and
+  taintedWithPath(userValue, arg, sourceNode, sinkNode) and
   isUserInput(userValue, cause)
 select arg,
-  "This value may flow through $@, originating from $@, and is a formatting argument to " +
-    printfFunction + ".", globalVarFromId(globalVar), globalVar, userValue, cause
+  "The value of this argument may come from $@ and is being used as a formatting argument to " +
+    printfFunction, userValue, cause