The following test failed in the JDK19 CI:

runtime/logging/RedefineClasses.java

Here's a snippet from the log file:

#section:main
----------messages:(5/423)----------
command: main -Xmx256m -XX:MaxMetaspaceSize=64m -javaagent:redefineagent.jar -Xlog:all=trace:file=all.log RedefineClasses
reason: User specified action: run main/othervm -Xmx256m -XX:MaxMetaspaceSize=64m -javaagent:redefineagent.jar -Xlog:all=trace:file=all.log RedefineClasses
Mode: othervm [/othervm specified]
Additional options from @modules: --add-modules java.compiler,java.instrument
elapsed time (seconds): 25.258
----------configuration:(3/57)----------
Boot Layer
  add modules: java.compiler java.instrument

----------System.out:(21/1838)----------
# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc: SuppressErrorAt=/g1CollectedHeap.inline.hpp:101
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/opt/mach5/mesos/work_dir/slaves/ff806ead-2cac-495d-9cbc-62116f99bf14-S13725/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/4b117863-2af8-4bc3-b053-27fc79e5c0b5/runs/d4560e38-0284-41d2-a63b-b8d51aa0981f/workspace/open/src/hotspot/share/gc/g1/g1CollectedHeap.inline.hpp:101), pid=10808, tid=5767
# assert(addr != __null) failed: invariant
#
# JRE version: Java(TM) SE Runtime Environment (19.0+10) (fastdebug build 19-ea+10-555)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 19-ea+10-555, mixed mode, tiered, compressed oops, compressed class ptrs, g1 gc, linux-amd64)
# Problematic frame:
# V [libjvm.so+0xc7882a] G1CMIsAliveClosure::do_object_b(oop)+0x38a
#
# Core dump will be written. Default location: Core dumps may be processed with "/opt/core.sh %p" (or dumping to /opt/mach5/mesos/work_dir/slaves/a2dc162d-743b-4800-9e92-31f85abb45b1-S166338/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/a045d65f-89dd-4550-aae7-c4091866e484/runs/eb522503-2821-48f1-9034-ac8b08880ec0/testoutput/test-support/jtreg_open_test_hotspot_jtreg_tier1_runtime/scratch/1/core.10808)
#
# An error report file with more information is saved as:
# /opt/mach5/mesos/work_dir/slaves/a2dc162d-743b-4800-9e92-31f85abb45b1-S166338/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/a045d65f-89dd-4550-aae7-c4091866e484/runs/eb522503-2821-48f1-9034-ac8b08880ec0/testoutput/test-support/jtreg_open_test_hotspot_jtreg_tier1_runtime/scratch/1/hs_err_pid10808.log
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#
----------System.err:(3/172)----------
java version "19-ea" 2022-09-20
Java(TM) SE Runtime Environment (fastdebug build 19-ea+10-555)
Java HotSpot(TM) 64-Bit Server VM (fastdebug build 19-ea+10-555, mixed mode)
----------rerun:(40/6962)*----------

Here's the crashing thread's stack:

--------------- T H R E A D ---------------

Current thread (0x00007fd040001760): WorkerThread "G1 Conc#2" [stack: 0x00007fd03d3ee000,0x00007fd03d4ee000] [id=5767]

Stack: [0x00007fd03d3ee000,0x00007fd03d4ee000], sp=0x00007fd03d4ec8b0, free space=1018k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0xc7882a] G1CMIsAliveClosure::do_object_b(oop)+0x38a
V [libjvm.so+0x171f4b4] ReferenceProcessor::discover_reference(oop, ReferenceType)+0x104
V [libjvm.so+0xc81b53] bool InstanceRefKlass::try_discover<narrowOop, G1CMOopClosure>(oop, ReferenceType, G1CMOopClosure*)+0x93
V [libjvm.so+0xc8326d] void InstanceRefKlass::oop_oop_iterate_discovery<narrowOop, G1CMOopClosure, AlwaysContains>(oop, ReferenceType, G1CMOopClosure*, AlwaysContains&) [clone .isra.0]+0x3d
V [libjvm.so+0xc835d0] void InstanceRefKlass::oop_oop_iterate<narrowOop, G1CMOopClosure>(oop, G1CMOopClosure*)+0x240
V [libjvm.so+0xc83bca] void OopOopIterateDispatch<G1CMOopClosure>::Table::oop_oop_iterate<InstanceRefKlass, narrowOop>(G1CMOopClosure*, oop, Klass*)+0x3a
V [libjvm.so+0xce28bb] void G1CMTask::process_grey_task_entry<true>(G1TaskQueueEntry)+0x2bb
V [libjvm.so+0xcda9dc] G1CMTask::drain_local_queue(bool) [clone .part.0] [clone .constprop.0]+0x8c
V [libjvm.so+0xcdaeb8] G1CMBitMapClosure::do_addr(HeapWordImpl**)+0x98
V [libjvm.so+0xcdc5ac] G1CMTask::do_marking_step(double, bool, bool)+0x7ac
V [libjvm.so+0xce79cd] G1CMConcurrentMarkingTask::work(unsigned int)+0x17d
V [libjvm.so+0x1a93a81] WorkerThread::run()+0x81
V [libjvm.so+0x1943830] Thread::call_run()+0x100
V [libjvm.so+0x16258d4] thread_native_entry(Thread*)+0x104

Since the crash is in G1, I'm starting this bug off in
hotspot/gc for initial triage.