undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.

test/hotspot/jtreg/compiler/loopopts/TestRangeCheckPredicatesControl.java

@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2020, 2024, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test id=Z
+ * @key stress randomness
+ * @requires vm.gc.Z
+ * @bug 8237859
+ * @summary A LoadP node has a wrong control input (too early) which results in an out-of-bounds read of an object array with ZGC.
+ *
+ * @run main/othervm -XX:+UseZGC compiler.loopopts.TestRangeCheckPredicatesControl
+ * @run main/othervm -XX:+UseZGC -XX:+UnlockDiagnosticVMOptions -XX:+IgnoreUnrecognizedVMOptions -XX:+StressGCM compiler.loopopts.TestRangeCheckPredicatesControl
+ */
+
+package compiler.loopopts;
+
+public class TestRangeCheckPredicatesControl {
+    static Wrapper w1 = new Wrapper();
+    static Wrapper w2 = new Wrapper();
+    static Wrapper w3 = new Wrapper();
+
+    public static void main(String[] args) {
+        for (int x = 0; x < 10000000; x++) {
+            test(x % 2 == 0);
+            test2(x % 2 == 0, x % 3 == 0);
+            test3(x % 2 == 0);
+            test4(x % 2 == 0);
+        }
+    }
+
+    private static class Wrapper {
+        long longs;
+        int a;
+        public void maybeMaskBits(boolean b) {
+            if (b) {
+                longs &= 0x1F1F1F1F;
+            }
+        }
+
+        public void maybeMaskBits2(boolean b, boolean c) {
+            if (b) {
+                longs &= 0x1F1F1F1F;
+            }
+            if (c) {
+                a += 344;
+            }
+        }
+    }
+
+    private static void test(boolean flag) {
+        Wrapper[] wrappers_array;
+        if (flag) {
+            wrappers_array = new Wrapper[] {w1, w2};
+        } else {
+            wrappers_array = new Wrapper[] {w1, w2, w3};
+        }
+
+        // This loop is first unswitched and then pre/main/post loops are created for both unswitched loops.
+        // Both loops are unrolled once (two iterations in main loop, one in pre loop). As a result, the main
+        // loop contains an access of wrappers_array[1] and wrappers_array[2]. If 'flag' is false, then the
+        // main loop is not entered. But the load for wrappers_array[2] is wrongly scheduled before deciding
+        // if the main loop is executed or not due to a wrong control input of the corresponding LoadP node.
+        // The LoadP node still has a control input from a loop predicate of the original loop to be unswitched.
+        // As a consequence, the access wrappers_array[2] is executed regardless of the value of 'flag' resulting
+        // in a segfault. This fix addresses the problem of not updating the control inputs for data nodes
+        // from a predicate before the pre loop to the main and post loop. The fix for JDK-8240227 updates the
+        // control dependencies to predicates of the original loop to be unswitched to newly cloned predicates
+        // of the unswitched loops.
+        for (int i = 0; i < wrappers_array.length; i++) {
+            wrappers_array[i].maybeMaskBits(flag);
+        }
+    }
+
+    // This test unswitches two times
+    private static void test2(boolean flag, boolean flag2) {
+        Wrapper[] wrappers_array;
+        Wrapper[] wrappers_array2;
+        if (flag) {
+            wrappers_array = new Wrapper[] {w1, w2};
+            wrappers_array2 = new Wrapper[] {w1, w2};
+        } else {
+            wrappers_array = new Wrapper[] {w1, w2, w3};
+            wrappers_array2 = new Wrapper[] {w1, w2, w3};
+        }
+
+        for (int i = 0; i < wrappers_array.length; i++) {
+            wrappers_array[i].maybeMaskBits(flag);
+            wrappers_array2[i].maybeMaskBits2(flag, flag2);
+        }
+    }
+
+    // Test without unswitching but wrong control dependencies for data nodes to predicates before the pre loop.
+    // There is no update for the data nodes belonging to main and post loop after pre/main/post loops are created.
+    private static void test3(boolean flag) {
+        Wrapper[] wrappers_array;
+        if (flag) {
+            wrappers_array = new Wrapper[] {w1, w2};
+        } else {
+            wrappers_array = new Wrapper[] {w1, w2, w3};
+        }
+
+        for (int i = 0; i < wrappers_array.length; i++) {
+            wrappers_array[i].longs &= 0x1F1F1F1F;
+        }
+    }
+
+    private static void test4(boolean flag) {
+        Wrapper[] wrappers_array;
+        Wrapper[] wrappers_array2;
+        if (flag) {
+            wrappers_array = new Wrapper[] {w1, w2};
+            wrappers_array2 = new Wrapper[] {w1, w2};
+        } else {
+            wrappers_array = new Wrapper[] {w1, w2, w3};
+            wrappers_array2 = new Wrapper[] {w1, w2, w3};
+        }
+
+        for (int i = 0; i < wrappers_array.length; i++) {
+            wrappers_array[i].longs &= 0x1F1F1F1F;
+            wrappers_array2[i].longs &= 0x1F1F1F1F;
+        }
+    }
+}