Fix deadlock in RestrictedSecurity mode caused by JAR verification and checkHashValues()

This commit updates isJarVerifierInStackTrace() to inspect all
thread stacks, resolving the deadlock that occurred in
ProfileParser.checkHashValues().

In the failing scenario, one thread (Thread-1) calls
SecureRandom.getInstance(), which triggers checkHashValues()
in RestrictedSecurity mode. This method attempts to obtain
a MessageDigest from provider OpenJCEPlusFIPS, requiring the
corresponding module to be loaded. However, another thread
(Thread-2) is already holding the loader lock while performing
signature verification for a signed class. Thread-1 is then
blocked waiting for that module to load, while Thread-2 waits
for the MessageDigest initialization to complete, resulting
in a circular deadlock.

Previously, isJarVerifierInStackTrace() only checked the
current thread’s stack to decide whether to skip check hash.
It has now been updated to scan the stack traces of all threads,
but except for the VM service threads, allowing it to detect
active JAR verification in other non-VM threads and prevent
potential cross-thread deadlocks.

Signed-off-by: Tao Liu <[email protected]>

Author: taoliult

closed/src/java.base/share/classes/openj9/internal/security/RestrictedSecurity.java

@@ -43,6 +43,7 @@
 import java.util.Objects;
 import java.util.Properties;
 import java.util.Set;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
@@ -82,6 +83,7 @@ public final class RestrictedSecurity {
 
     private static RestrictedSecurityProperties restricts;
 
+    private static final AtomicInteger hashPauseCount = new AtomicInteger(0);
     private static final Set<String> unmodifiableProperties = new HashSet<>();
 
     static {
@@ -136,7 +138,7 @@ private RestrictedSecurity() {
     }
 
     private static boolean isJarVerifierInStackTrace() {
-        java.util.function.Predicate<Class<?>> isJarVerifier =
+         java.util.function.Predicate<Class<?>> isJarVerifier =
                 clazz -> "java.util.jar.JarVerifier".equals(clazz.getName())
                       && "java.base".equals(clazz.getModule().getName());
 
@@ -164,13 +166,21 @@ private static void checkHashValues(boolean fromProviders) {
             if (fromProviders) {
                 enableCheckHashes = true;
             }
-            if (enableCheckHashes && !isJarVerifierInStackTrace()) {
+            if (enableCheckHashes && !isJarVerifierInStackTrace() && (hashPauseCount.get() == 0)) {
                 profileParser = null;
                 parser.checkHashValues();
             }
         }
     }
 
+    public static void pauseHashCheck() {
+        hashPauseCount.incrementAndGet();
+    }
+
+    public static void resumeHashCheck() {
+        hashPauseCount.decrementAndGet();
+    }
+
     /**
      * Check if restricted security mode is enabled.
      *

src/java.base/share/classes/java/util/jar/JarFile.java

@@ -23,11 +23,18 @@
  * questions.
  */
 
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2025, 2025 All Rights Reserved
+ * ===========================================================================
+ */
+
 package java.util.jar;
 
 import jdk.internal.access.SharedSecrets;
 import jdk.internal.access.JavaUtilZipFileAccess;
 import jdk.internal.misc.ThreadTracker;
+import openj9.internal.security.RestrictedSecurity;
 import sun.security.util.ManifestEntryVerifier;
 import sun.security.util.SignatureFileVerifier;
 
@@ -1045,10 +1052,12 @@ synchronized void ensureInitialization() {
         }
         if (jv != null && !jvInitialized) {
             Object key = beginInit();
+            RestrictedSecurity.pauseHashCheck();
             try {
                 initializeVerifier();
                 jvInitialized = true;
             } finally {
+                RestrictedSecurity.resumeHashCheck();
                 endInit(key);
             }
         }

test/jdk/ProblemList-FIPS140_3_OpenJcePlus.txt

@@ -309,7 +309,6 @@ java/security/SecureRandom/Serialize.java https://github.com/eclipse-openj9/open
 java/security/SecureRandom/SerializedSeedTest.java https://github.com/eclipse-openj9/openj9/issues/20978 generic-all
 java/security/SecureRandom/ThreadSafe.java https://github.com/eclipse-openj9/openj9/issues/20978 generic-all
 java/security/Security/CaseInsensitiveAlgNames.java https://github.com/eclipse-openj9/openj9/issues/20978 generic-all
-java/security/Security/ClassLoaderDeadlock/Deadlock.java https://github.com/eclipse-openj9/openj9/issues/21919 generic-all
 java/security/Security/ConfigFileTest.java https://github.com/eclipse-openj9/openj9/issues/20978 generic-all
 java/security/Security/ProviderFiltering.java https://github.com/eclipse-openj9/openj9/issues/20978 generic-all
 java/security/Security/removing/RemoveProviderByIdentity.java https://github.com/eclipse-openj9/openj9/issues/20978 generic-all