Unable to find actual suspect through code search and also from the provided CL under regression range, hence adding appropriate label and leaving it as untriaged for further updates.

Thanks!

restarted the task to redo regression

ClusterFuzz has detected this issue as fixed in range 535922:535929.

Detailed report: https://clusterfuzz.com/testcase?key=5103975154843648

Fuzzer: j00ru_htmlcss_fuzz
Job Type: linux_ubsan_vptr_chrome
Platform Id: linux

Crash Type: Null-dereference READ
Crash Address: 0x000000000008
Crash State:
  blink::RuleSet::CompactPendingRules
  blink::RuleSet::CompactRules
  blink::StyleEngine::ApplyRuleSetChanges
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=linux_ubsan_vptr_chrome&range=535301:535306
Fixed: https://clusterfuzz.com/revisions?job=linux_ubsan_vptr_chrome&range=535922:535929

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=5103975154843648

See https://github.com/google/clusterfuzz-tools for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

ClusterFuzz testcase 5103975154843648 is verified as fixed, so closing issue as verified.

If this is incorrect, please add ClusterFuzz-Wrong label and re-open the issue.