The following test failed in the JDK18 CI:

vmTestbase/nsk/jvmti/RedefineClasses/StressRedefine/TestDescription.java

Here's a snippet from the log file:

Got expected exception: java.lang.reflect.InvocationTargetException
Got expected exception: java.lang.reflect.InvocationTargetException
#
# A fatal error has been detected by the Java Runtime Environment:
#
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x000000000000000d, pid=43520, tid=48028
#
# JRE version: Java(TM) SE Runtime Environment (18.0+26) (fastdebug build 18-ea+26-1792)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 18-ea+26-1792, mixed mode, sharing, tiered, compressed class ptrs, z gc, windows-amd64)
# Problematic frame:
# C 0x000000000000000d
#
# Core dump will be written. Default location: T:\\testoutput\\test-support\\jtreg_open_test_hotspot_jtreg_vmTestbase_nsk_jvmti_quick\\scratch\\0\\hs_err_pid43520.mdmp
#
# An error report file with more information is saved as:
# T:\\testoutput\\test-support\\jtreg_open_test_hotspot_jtreg_vmTestbase_nsk_jvmti_quick\\scratch\\0\\hs_err_pid43520.log
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#
s() is successfully done
>>>>>>>> Invoke RedefineClasses():
new class byte count=2287
t:\\workspace\\open\\test\\hotspot\\jtreg\\vmTestbase\\nsk\\jvmti\\RedefineClasses\\StressRedefine\\stressRedefine.cpp: Failed to call RedefineClasses():
the function returned error 60: JVMTI_ERROR_INVALID_CLASS_FORMAT
For more info about this error see the JVMTI spec.
>>>>>>>> Invoke RedefineClasses():
new class byte count=2287
<<<<<<<< RedefineClasses() is successfully done
>>>>>>>> Invoke RedefineClasses():
new class byte count=2287
<<<<<<<< RedefineClasses() is successfully done
>>>>>>>> Invoke RedefineClasses():
new class byte count=2287
<<<<<<<< RedefineClasses() is successfully done
>>>>>>>> Invoke RedefineClasses():
new class byte count=2287
<<<<<<<< RedefineClasses() is successfully done
t:\\workspace\\open\\test\\hotspot\\jtreg\\vmTestbase\\nsk\\jvmti\\RedefineClasses\\StressRedefine\\stressRedefine.cpp: Failed to call RedefineClasses():
the function returned error 60: JVMTI_ERROR_INVALID_CLASS_FORMAT
For more info about this error see the JVMTI spec.
<<<<<<<< RedefineClasses() is successfully done
<<<<<<<< RedefineClasses() is successfully done
----------System.err:(11/3315)*----------


Here's the crashing thread's stack:

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

Current thread (0x00000275aeaa4e60): WorkerThread "ZWorker#0" [stack: 0x00000093d3500000,0x00000093d3600000] [id=48028]

Stack: [0x00000093d3500000,0x00000093d3600000], sp=0x00000093d35ff4a8, free space=1021k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
C 0x000000000000000d


siginfo: EXCEPTION_ACCESS_VIOLATION (0xc0000005), data execution prevention violation at address 0x000000000000000d

That looks like a bad jump or call to 0x000000000000000d. Ouch!

There are a couple of other unresolved bugs for this same test:

JDK-8269633 vmTestbase/nsk/jvmti/RedefineClasses/StressRedefine/TestDescription.java crashed with oopDesc::size_given_klass+0x6

JDK-8274154 vmTestbase/nsk/jvmti/RedefineClasses/StressRedefine/TestDescription.java timed out