8333149: ubsan : memset on nullptr target detected in jvmtiEnvBase.cp…

…p get_object_monitor_usage Backport-of: 43a2f17342af8f5bf1f5823df9fa0bf0bdfdfce2
openjdk · Aug 22, 2024 · 24f453c · 24f453c · openjdk-notifier · Aug 22, 2024
1 parent dc8365c
commit 24f453c
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/src/hotspot/share/prims/jvmtiEnvBase.cpp b/src/hotspot/share/prims/jvmtiEnvBase.cpp
@@ -1515,8 +1515,12 @@ JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject objec
 
     // Number of waiters may actually be less than the waiter count.
     // So null out memory so that unused memory will be null.
-    memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *));
-    memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *));
+    if (ret.waiters != nullptr) {
+      memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *));
+    }
+    if (ret.notify_waiters != nullptr) {
+      memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *));
+    }
 
     if (ret.waiter_count > 0) {
       // we have contending and/or waiting threads