While testing Elasticsearch with JDK 21 (21.0.1+12). We've seen the following crash now quite often (every other day):

#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x00007efe31e88f0e, pid=98535, tid=98552
#
# JRE version: OpenJDK Runtime Environment (21.0.1+12) (build 21.0.1+12-29)
# Java VM: OpenJDK 64-Bit Server VM (21.0.1+12-29, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, linux-amd64)
# Problematic frame:
# V [libjvm.so+0xb93f0e] PhaseIdealLoop::build_loop_late_post_work(Node*, bool)+0xce
#
# Core dump will be written. Default location: Core dumps may be processed with "/usr/share/apport/apport -p%p -s%s -c%c -d%d -P%P -u%u -g%g -- %E" (or dumping to /dev/shm/bk/bk-agent-prod-gcp-1701768547667347876/elastic/elasticsearch-pull-request/server/build/testrun/test/core.98535)
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#

--------------- S U M M A R Y ------------

Command Line: -Des.insecure_network_trace_enabled=true -Des.scripting.update.ctx_in_params=false -Des.search.rewrite_sort=true -Des.transport.cname_in_publish_address=true -Dgradle.dist.lib=/opt/buildkite-agent/.gradle/wrapper/dists/gradle-8.5-all/3zlzzgtsutfj0pbojr50n2l7z/gradle-8.5/lib -Dgradle.user.home=/opt/buildkite-agent/.gradle -Dgradle.worker.jar=/opt/buildkite-agent/.gradle/caches/8.5/workerMain/gradle-worker.jar -Dio.netty.noKeySetOptimization=true -Dio.netty.noUnsafe=true -Dio.netty.recycler.maxCapacityPerThread=0 -Djava.awt.headless=true -Djava.locale.providers=SPI,COMPAT -Djava.security.manager=allow -Djna.nosys=true -Dorg.gradle.internal.worker.tmpdir=/dev/shm/bk/bk-agent-prod-gcp-1701768547667347876/elastic/elasticsearch-pull-request/server/build/tmp/test/work -Dorg.gradle.native=false -Dtests.artifact=server -Dtests.gradle=true -Dtests.logger.level=WARN -Dtests.security.manager=true -Dtests.seed=74BBD5155B19065C -Dtests.task=:server:test --add-opens=java.base/java.security.cert=ALL-UNNAMED --add-opens=java.base/java.nio.channels=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/javax.net.ssl=ALL-UNNAMED --add-opens=java.base/java.nio.file=ALL-UNNAMED --add-opens=java.base/java.time=ALL-UNNAMED --add-opens=java.management/java.lang.management=ALL-UNNAMED -XX:+HeapDumpOnOutOfMemoryError -esa -XX:HeapDumpPath=/dev/shm/bk/bk-agent-prod-gcp-1701768547667347876/elastic/elasticsearch-pull-request/server/build/heapdump -Xms512m -Xmx512m -Dfile.encoding=UTF-8 -Djava.io.tmpdir=/dev/shm/bk/bk-agent-prod-gcp-1701768547667347876/elastic/elasticsearch-pull-request/server/build/testrun/test/temp -Duser.country -Duser.language=en -Duser.variant -ea worker.org.gradle.process.internal.worker.GradleWorkerMain 'Gradle Test Executor 360'

Host: Intel(R) Xeon(R) CPU @ 2.30GHz, 32 cores, 94G, Ubuntu 20.04.6 LTS
Time: Tue Dec 5 09:43:58 2023 UTC elapsed time: 128.242318 seconds (0d 0h 2m 8s)

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

Current thread (0x00007efe2c2b4670): JavaThread "C2 CompilerThread0" daemon [_thread_in_native, id=98552, stack(0x00007efe02e19000,0x00007efe02f1a000) (1028K)]


Current CompileTask:
C2: 128242 27278 % 4 org.apache.lucene.util.RadixSelector::computeCommonPrefixLengthAndBuildHistogram @ 83 (231 bytes)

Stack: [0x00007efe02e19000,0x00007efe02f1a000], sp=0x00007efe02f15530, free space=1009k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0xb93f0e] PhaseIdealLoop::build_loop_late_post_work(Node*, bool)+0xce
V [libjvm.so+0xb94790] PhaseIdealLoop::build_loop_late(VectorSet&, Node_List&, Node_Stack&)+0x170
V [libjvm.so+0xb95088] PhaseIdealLoop::build_and_optimize()+0x738
V [libjvm.so+0x6447ca] Compile::Optimize()+0xc6a
V [libjvm.so+0x64647d] Compile::Compile(ciEnv*, ciMethod*, int, Options, DirectiveSet*)+0xf1d
V [libjvm.so+0x5742c0] C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x120
V [libjvm.so+0x64c147] CompileBroker::invoke_compiler_on_method(CompileTask*)+0xa97
V [libjvm.so+0x64f228] CompileBroker::compiler_thread_loop()+0x698
V [libjvm.so+0x8f4c68] JavaThread::thread_main_inner() [clone .part.0]+0xb8
V [libjvm.so+0xe99918] Thread::call_run()+0xa8
V [libjvm.so+0xcbf89a] thread_native_entry(Thread*)+0xda

siginfo: si_signo: 11 (SIGSEGV), si_code: 1 (SEGV_MAPERR), si_addr: 0x0000000000000008