Graceful handling of fuzzer crashes

[vy]

I am fuzzing a JVM application. JVM crashes due to fuzzing are false positives and I want to eliminate them. For that purpose, I updated LLVMFuzzerTestOneInput scripts to exit 0 on JVM failures, though this is not resulting in a successful fuzzer execution I was expecting. That is, in the associated ClusterFuzz bucket, I see a foo.testcase file along with a foo.log file, and this, I presume, indicates that it is received as a fuzzer failure by the system.

Click to see the ClusterFuzz fuzzer execution log snippet

...
INFO: Instrumented org.apache.logging.log4j.core.util.DefaultShutdownCallbackRegistry$RegisteredCancellable (took 32 ms, size +7%)
ALARM: working on the last Unit for 25 seconds
       and the timeout value is 25 (use -timeout=N to change)
MS: 0 ; base unit: 0000000000000000000000000000000000000000


artifact_prefix='/mnt/scratch0/clusterfuzz/bot/inputs/fuzzer-testcases/'; Test unit written to /mnt/scratch0/clusterfuzz/bot/inputs/fuzzer-testcases/timeout-da39a3ee5e6b4b0d3255bfef95601890afd80709
Base64:
==40704== ERROR: libFuzzer: timeout after 25 seconds
#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (javaCalls.cpp:64), pid=40704, tid=40723
#  guarantee(thread->can_call_java()) failed: cannot make java calls from the native compiler
#
# JRE version: OpenJDK Runtime Environment Zulu17.52+17-CA (17.0.12+7) (build 17.0.12+7-LTS)
# Java VM: OpenJDK 64-Bit Server VM Zulu17.52+17-CA (17.0.12+7-LTS, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, parallel gc, linux-amd64)
# Problematic frame:
# V  [libjvm.so+0x81f011]INFO: Instrumented org.apache.logging.log4j.core.util.NetUtils (took 51 ms, size +15%)
  JavaCallWrapper::JavaCallWrapper(methodHandle const&, Handle, JavaValue*, JavaThread*)+0x1f1
#
# Core dump will be written. Default location: /mnt/scratch0/clusterfuzz/bot/builds/clusterfuzz-builds_log4j2_6f1a723a8086d7a337b75af460e0eacd138ef8b0/revisions/core
#
# An error report file with more information is saved as:
# /mnt/scratch0/clusterfuzz/bot/builds/clusterfuzz-builds_log4j2_6f1a723a8086d7a337b75af460e0eacd138ef8b0/revisions/hs_err_pid40704.log
#
# Compiler replay data is saved as:
# /mnt/scratch0/clusterfuzz/bot/builds/clusterfuzz-builds_log4j2_6f1a723a8086d7a337b75af460e0eacd138ef8b0/revisions/replay_pid40704.log
#
# If you would like to submit a bug report, please visit:
#   http://www.azul.com/support/
#
==40704== ERROR: libFuzzer: deadly signal
NOTE: libFuzzer has rudimentary signal handlers.
      Combine libFuzzer with AddressSanitizer or similar for better crash reports.
SUMMARY: libFuzzer: deadly signal
MS: 0 ; base unit: 0000000000000000000000000000000000000000


artifact_prefix='/mnt/scratch0/clusterfuzz/bot/inputs/fuzzer-testcases/'; Test unit written to /mnt/scratch0/clusterfuzz/bot/inputs/fuzzer-testcases/crash-da39a3ee5e6b4b0d3255bfef95601890afd80709
Base64:
stat::number_of_executed_units: 1
stat::average_exec_per_sec:     0
stat::new_units_added:          0
stat::slowest_unit_time_sec:    0
stat::peak_rss_mb:              994
INFO: exiting: 77 time: 906s
Detected JRE crash; exiting with success, since it doesn't qualify as a fuzzing failure.
cf::fuzzing_strategies: fork:2,extra_sanitizers:1

How can I gracefully exit from fuzzer scripts in case of libFuzzer crashes?