JS: Fix a few perf issues

javascript/ql/lib/semmle/javascript/dataflow/internal/DataFlowPrivate.qll

@@ -612,6 +612,8 @@ predicate nodeIsHidden(Node node) {
   or
   node instanceof FlowSummaryIntermediateAwaitStoreNode
   or
+  node instanceof FlowSummaryDefaultExceptionalReturn
+  or
   node instanceof CaptureNode
   or
   // Hide function expressions, as capture-flow causes them to appear in unhelpful ways

javascript/ql/lib/semmle/javascript/security/dataflow/ExceptionXssQuery.qll

@@ -153,6 +153,8 @@ module ExceptionXssConfig implements DataFlow::StateConfigSig {
     canThrowSensitiveInformation(node1) and
     node2 = getExceptionTarget(node1)
   }
+
+  int accessPathLimit() { result = 1 }
 }
 
 /**

javascript/ql/lib/semmle/javascript/security/dataflow/UnvalidatedDynamicMethodCallCustomizations.qll

@@ -182,7 +182,11 @@ module UnvalidatedDynamicMethodCall {
       exists(InvokeExpr invk |
         this = invk.getCallee().flow() and
         // don't flag invocations inside a try-catch
-        not invk.getASuccessor() instanceof CatchClause
+        not invk.getASuccessor() instanceof CatchClause and
+        // Filter out `foo.bar()` calls as they usually aren't interesting.
+        // Technically this could be reachable if preceded by `foo.bar = obj[taint]`
+        // but such sinks are more likely to be FPs and also slow down the query.
+        not invk.getCallee() instanceof DotExpr
       )
     }
 

javascript/ql/lib/semmle/javascript/security/dataflow/UnvalidatedDynamicMethodCallQuery.qll

@@ -24,6 +24,17 @@ deprecated private class ConcreteMaybeFromProto extends MaybeFromProto {
   ConcreteMaybeFromProto() { this = this }
 }
 
+/** Gets a data flow node referring to an instance of `Map`. */
+private DataFlow::SourceNode mapObject(DataFlow::TypeTracker t) {
+  t.start() and
+  result = DataFlow::globalVarRef("Map").getAnInstantiation()
+  or
+  exists(DataFlow::TypeTracker t2 | result = mapObject(t2).track(t2, t))
+}
+
+/** Gets a data flow node referring to an instance of `Map`. */
+private DataFlow::SourceNode mapObject() { result = mapObject(DataFlow::TypeTracker::end()) }
+
 /**
  * A taint-tracking configuration for reasoning about unvalidated dynamic method calls.
  */
@@ -67,7 +78,9 @@ module UnvalidatedDynamicMethodCallConfig implements DataFlow::StateConfigSig {
       not PropertyInjection::hasUnsafeMethods(read.getBase().getALocalSource())
     )
     or
-    exists(DataFlow::SourceNode base, DataFlow::CallNode get | get = base.getAMethodCall("get") |
+    exists(DataFlow::CallNode get |
+      get = mapObject().getAMethodCall("get") and
+      get.getNumArgument() = 1 and
       node1 = get.getArgument(0) and
       node2 = get
     ) and

javascript/ql/src/Security/CWE-915/PrototypePollutingFunction.ql

@@ -277,6 +277,12 @@ module PropNameTrackingConfig implements DataFlow::StateConfigSig {
     node instanceof DataFlow::VarAccessBarrier or
     node = DataFlow::MakeBarrierGuard<BarrierGuard>::getABarrierNode()
   }
+
+  int accessPathLimit() {
+    // Speed up the query. For the pattern we're looking for the value rarely
+    // flows through any contents, apart from a capture content.
+    result = 1
+  }
 }
 
 class FlowState = PropNameTrackingConfig::FlowState;