Unable to find the suspect through code search and also from the provided CL, hence assigning to @iclelland who have worked on similar  issue 802259  which got fixed recently. 

Thanks!

This looks like a similar issue to  issue 802259 , except that there is no unicode / high ascii in the test case. However, it is a 67K string being interpreted as an origin, hitting the worst-case performance characteristics of punycode, causing the timeouts.

I'll put a general sanity-length check in to the FP parser, which should fix this.

ClusterFuzz has detected this issue as fixed in range 550604:550608.

Detailed report: https://clusterfuzz.com/testcase?key=5110647453646848

Fuzzer: libFuzzer_feature_policy_fuzzer
Job Type: libfuzzer_chrome_ubsan
Platform Id: linux

Crash Type: Timeout (exceeds 25 secs)
Crash Address: 
Crash State:
  feature_policy_fuzzer
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=498203:498244
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=550604:550608

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=5110647453646848

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reference.md 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 5110647453646848 is verified as fixed, so closing issue as verified.

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