Merge pull request #4081 from aschackmull/java/dispatch-ctx-this-param

Approved by aibaars

Author: codeql-ci

java/ql/src/semmle/code/java/dataflow/internal/DataFlowDispatch.qll

@@ -1,5 +1,7 @@
 private import java
 private import DataFlowPrivate
+private import DataFlowUtil
+private import semmle.code.java.dataflow.InstanceAccess
 import semmle.code.java.dispatch.VirtualDispatch
 
 private module DispatchImpl {
@@ -17,6 +19,13 @@ private module DispatchImpl {
       not p.isVarargs() and
       c = ma.getEnclosingCallable()
     )
+    or
+    exists(OwnInstanceAccess ia |
+      2 <= strictcount(viableImpl(ma)) and
+      (ia.isExplicit(ma.getQualifier()) or ia.isImplicitMethodQualifier(ma)) and
+      i = -1 and
+      c = ma.getEnclosingCallable()
+    )
   }
 
   /**
@@ -37,18 +46,32 @@ private module DispatchImpl {
    * relevant call context.
    */
   private predicate contextArgHasType(Call ctx, int i, RefType t, boolean exact) {
-    exists(Expr arg, Expr src |
-      relevantContext(ctx, i) and
-      ctx.getArgument(i) = arg and
-      src = variableTrack(arg) and
-      exists(RefType srctype | srctype = src.getType() |
-        exists(TypeVariable v | v = srctype |
-          t = v.getUpperBoundType+() and not t instanceof TypeVariable
-        )
+    relevantContext(ctx, i) and
+    exists(RefType srctype |
+      exists(Expr arg, Expr src |
+        i = -1 and
+        ctx.getQualifier() = arg
         or
-        t = srctype and not srctype instanceof TypeVariable
-      ) and
-      if src instanceof ClassInstanceExpr then exact = true else exact = false
+        ctx.getArgument(i) = arg
+      |
+        src = variableTrack(arg) and
+        srctype = src.getType() and
+        if src instanceof ClassInstanceExpr then exact = true else exact = false
+      )
+      or
+      exists(Node arg |
+        i = -1 and
+        not exists(ctx.getQualifier()) and
+        getInstanceArgument(ctx) = arg and
+        arg.getTypeBound() = srctype and
+        if ctx instanceof ClassInstanceExpr then exact = true else exact = false
+      )
+    |
+      exists(TypeVariable v | v = srctype |
+        t = v.getUpperBoundType+() and not t instanceof TypeVariable
+      )
+      or
+      t = srctype and not srctype instanceof TypeVariable
     )
   }
 

java/ql/test/library-tests/dataflow/callctx/A.java

@@ -0,0 +1,63 @@
+public class A {
+  static void sink(Object x) { }
+
+  static Object source() { return null; }
+
+  static class C1 {
+    C1() { }
+
+    C1(Object x) {
+      foo(x);
+    }
+
+    void wrapFoo1(Object x) {
+      foo(x);
+    }
+
+    void wrapFoo2(Object x) {
+      this.foo(x);
+    }
+
+    void foo(Object x) {
+      Object c1 = x;
+      sink(c1);
+    }
+  }
+
+  static class C2 extends C1 {
+    C2() { }
+
+    C2(Object x) {
+      super(x);
+    }
+
+    void foo(Object x) {
+      Object c2 = x;
+      sink(c2);
+    }
+
+    void callWrapFoo2() {
+      wrapFoo2(source());
+    }
+  }
+
+  static void wrapFoo3(C1 c1, Object x) {
+    c1.foo(x);
+  }
+
+  void test(C1 c) {
+    c.wrapFoo1(source());
+    c.wrapFoo2(source());
+    wrapFoo3(c, source());
+
+    new C1(source());
+    new C1().wrapFoo1(source());
+    new C1().wrapFoo2(source());
+    wrapFoo3(new C1(), source());
+
+    new C2(source());
+    new C2().wrapFoo1(source());
+    new C2().wrapFoo2(source());
+    wrapFoo3(new C2(), source());
+  }
+}

java/ql/test/library-tests/dataflow/callctx/test.expected

@@ -0,0 +1,15 @@
+| A.java:40:16:40:23 | source(...) | A.java:36:12:36:13 | c2 |
+| A.java:49:16:49:23 | source(...) | A.java:23:12:23:13 | c1 |
+| A.java:49:16:49:23 | source(...) | A.java:36:12:36:13 | c2 |
+| A.java:50:16:50:23 | source(...) | A.java:23:12:23:13 | c1 |
+| A.java:50:16:50:23 | source(...) | A.java:36:12:36:13 | c2 |
+| A.java:51:17:51:24 | source(...) | A.java:23:12:23:13 | c1 |
+| A.java:51:17:51:24 | source(...) | A.java:36:12:36:13 | c2 |
+| A.java:53:12:53:19 | source(...) | A.java:23:12:23:13 | c1 |
+| A.java:54:23:54:30 | source(...) | A.java:23:12:23:13 | c1 |
+| A.java:55:23:55:30 | source(...) | A.java:23:12:23:13 | c1 |
+| A.java:56:24:56:31 | source(...) | A.java:23:12:23:13 | c1 |
+| A.java:58:12:58:19 | source(...) | A.java:36:12:36:13 | c2 |
+| A.java:59:23:59:30 | source(...) | A.java:36:12:36:13 | c2 |
+| A.java:60:23:60:30 | source(...) | A.java:36:12:36:13 | c2 |
+| A.java:61:24:61:31 | source(...) | A.java:36:12:36:13 | c2 |

java/ql/test/library-tests/dataflow/callctx/test.ql

@@ -0,0 +1,15 @@
+import java
+import semmle.code.java.dataflow.DataFlow
+import DataFlow
+
+class Conf extends Configuration {
+  Conf() { this = "qqconf" }
+
+  override predicate isSource(Node n) { n.asExpr().(MethodAccess).getMethod().hasName("source") }
+
+  override predicate isSink(Node n) { n.asExpr().(Argument).getCall().getCallee().hasName("sink") }
+}
+
+from Node src, Node sink, Conf c
+where c.hasFlow(src, sink)
+select src, sink