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/jdk/java/lang/ProcessBuilder/NonPipelineLeaksFD.java

@@ -0,0 +1,182 @@
+/*
+ * Copyright (c) 2022, 2026, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2026, IBM Corp.
+ * 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.
+ */
+
+import java.io.*;
+
+/*
+ * @test id=FORK
+ * @summary Check that we don't accumulate leaked FDs in the parent process
+ * @requires os.family == "linux"
+ * @library /test/lib
+ * @run main/othervm -Djdk.lang.Process.launchMechanism=fork NonPipelineLeaksFD
+ */
+
+/*
+ * @test id=VFORK
+ * @summary Check that we don't accumulate leaked FDs in the parent process
+ * @requires os.family == "linux"
+ * @library /test/lib
+ * @run main/othervm -Djdk.lang.Process.launchMechanism=vfork NonPipelineLeaksFD
+ */
+
+/*
+ * @test id=POSIX_SPAWN
+ * @summary Check that we don't accumulate leaked FDs in the parent process
+ * @requires os.family == "linux"
+ * @library /test/lib
+ * @run main/othervm -Djdk.lang.Process.launchMechanism=posix_spawn NonPipelineLeaksFD
+ */
+
+public class NonPipelineLeaksFD {
+
+    final static int repeatCount = 50;
+
+    // Similar to PilelineLeaksFD, but where PilelineLeaksFD checks that the parent process
+    // does not leak file descriptors when invoking a pipeline, here we check that we don't
+    // leak FDs when executing simple (non-pipelined) programs but we test a wider span of
+    // redirection modes in both successful and failing variants.
+
+    // How this works:
+    //
+    // We execute a mix of failing and succeeding child process starts with various
+    // flavors of IO redirections many times; we observe the open file descriptors
+    // before and afterwards. Test fails if we have significantly more file descriptors
+    // open afterwards than before.
+
+    static int countNumberOfOpenFileDescriptors() {
+        return new File("/proc/self/fd").list().length;
+    }
+
+    static void printOpenFileDescriptors() {
+        long mypid =  ProcessHandle.current().pid();
+        try(Process p = new ProcessBuilder("lsof", "-p", Long.toString(mypid))
+                .inheritIO().start()) {
+            p.waitFor();
+        } catch (InterruptedException | IOException ignored) {
+            // Quietly swallow; it was just an attempt.
+        }
+    }
+
+    static String readFirstLineOf(File f) {
+        String result;
+        try (BufferedReader b = new BufferedReader(new FileReader(f))){
+            result = b.readLine();
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+        return result;
+    }
+
+    static void runThisExpectSuccess(ProcessBuilder bld) {
+        try(Process p = bld.start()) {
+            p.waitFor();
+            if (p.exitValue() != 0) {
+                throw new RuntimeException("Unexpected exitcode");
+            }
+        } catch (IOException | InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    static void runThisExpectError(ProcessBuilder bld) {
+        boolean failed = false;
+        try(Process p = bld.start()) {
+            p.waitFor();
+        } catch (IOException | InterruptedException e) {
+            failed = true;
+        }
+        if (!failed) {
+            throw new RuntimeException("Expected Error");
+        }
+    }
+
+    static void runPosWithPipes() {
+        ProcessBuilder bld = new ProcessBuilder("sh", "-c", "echo hallo");
+        runThisExpectSuccess(bld);
+    }
+
+    static void runPosWithInheritIO() {
+        ProcessBuilder bld = new ProcessBuilder("sh", "-c", "echo hallo").inheritIO();
+        runThisExpectSuccess(bld);
+    }
+
+    static void runPosWithRedirectToFile() {
+        File fo = new File("test.out");
+        ProcessBuilder bld = new ProcessBuilder("sh", "-c", "echo hallo");
+        bld.redirectOutput(ProcessBuilder.Redirect.to(fo));
+        runThisExpectSuccess(bld);
+        if (!readFirstLineOf(fo).equals("hallo")) {
+            throw new RuntimeException("mismatch");
+        }
+    }
+
+    static void runNegWithPipes() {
+        ProcessBuilder bld = new ProcessBuilder("doesnotexist");
+        runThisExpectError(bld);
+    }
+
+    static void runNegWithInheritIO() {
+        ProcessBuilder bld = new ProcessBuilder("doesnotexist").inheritIO();
+        runThisExpectError(bld);
+    }
+
+    static void runNegWithRedirectToFile() {
+        File fo = new File("test.out");
+        ProcessBuilder bld = new ProcessBuilder("doesnotexist");
+        bld.redirectOutput(ProcessBuilder.Redirect.to(fo));
+        runThisExpectError(bld);
+    }
+
+    static void doTestNTimesAndCountFDs(Runnable runnable, String name) {
+        System.out.println(name);
+        int c1 = countNumberOfOpenFileDescriptors();
+        for (int i = 0; i < repeatCount; i++) {
+            runnable.run();
+        }
+        int c2 = countNumberOfOpenFileDescriptors();
+        System.out.printf("%d->%d", c1, c2);
+    }
+
+    public static void main(String[] args) throws Exception {
+        System.out.println("jdk.lang.Process.launchMechanism=" +
+                System.getProperty("jdk.lang.Process.launchMechanism"));
+        int c1 = countNumberOfOpenFileDescriptors();
+        doTestNTimesAndCountFDs(NonPipelineLeaksFD::runPosWithPipes, "runPosWithPipes");
+        doTestNTimesAndCountFDs(NonPipelineLeaksFD::runPosWithInheritIO, "runPosWithInheritIO");
+        doTestNTimesAndCountFDs(NonPipelineLeaksFD::runPosWithRedirectToFile, "runPosWithRedirectToFile");
+        doTestNTimesAndCountFDs(NonPipelineLeaksFD::runNegWithPipes, "runNegWithPipes");
+        doTestNTimesAndCountFDs(NonPipelineLeaksFD::runNegWithInheritIO, "runNegWithInheritIO");
+        doTestNTimesAndCountFDs(NonPipelineLeaksFD::runNegWithRedirectToFile, "runNegWithRedirectToFile");
+        int c2 = countNumberOfOpenFileDescriptors();
+
+        System.out.printf("All tests: %d->%d", c1, c2);
+        printOpenFileDescriptors();
+
+        final int fudge = 10;
+        if (c2 > (c1 + fudge)) {
+            throw new RuntimeException(
+                    String.format("Leak suspected (%d->%d) - see lsof output", c1, c2));
+        }
+    }
+}