behdad: this is a RBS use of uninitialised value. Can you please take a look?

behdad: Uh oh! This issue still open and hasn't been updated in the last 14 days. This is a serious vulnerability, and we want to ensure that there's progress. Could you please leave an update with the current status and any potential blockers?

If you're not the right owner for this issue, could you please remove yourself as soon as possible or help us find the right one?

If the issue is fixed or you can't reproduce it, please close the bug. If you've started working on a fix, please set the status to Started.

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Could you look into this Behdad and comment on the implications?

Humm.  I cannot reproduce this using the test case and valgrind.  Can someone help me reproduce please?

You need to create a MSAN libFuzzer build, see instructions at https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md (Reproducing LibFuzzer + MSan bugs section)

Thanks. But that page doesn't help one set it up without a Chrome build first, which is outside of my current resources.

Ok, I just checked and copy of harfbuzz we carry is from September.  I suggest we update to latest version first and see if this still happens.  I'm out of ideas otherwise, short of someone pointing me to a Linux binary I can download to run MSAN.

behdad: Uh oh! This issue still open and hasn't been updated in the last 29 days. This is a serious vulnerability, and we want to ensure that there's progress. Could you please leave an update with the current status and any potential blockers?

If you're not the right owner for this issue, could you please remove yourself as soon as possible or help us find the right one?

If the issue is fixed or you can't reproduce it, please close the bug. If you've started working on a fix, please set the status to Started.

Thanks for your time! To disable nags, add the Disable-Nags label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

ClusterFuzz has detected this issue as fixed in range 441170:441211.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=5887298756673536

Fuzzer: libfuzzer_harfbuzz_fuzzer
Job Type: libfuzzer_chrome_msan
Platform Id: linux

Crash Type: Use-of-uninitialized-value
Crash Address: 
Crash State:
  OT::RangeRecord::cmp
  int OT::SortedArrayOf<OT::RangeRecord, OT::IntType<unsigned short, 2u> >::bsearc
  OT::CoverageFormat2::get_coverage
  
Recommended Security Severity: Medium

Regressed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_msan&range=423366:423427
Fixed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_msan&range=441170:441211

Minimized Testcase (0.99 Kb): https://cluster-fuzz.appspot.com/download/AMIfv96dNzZZ2FOX6_KBINrrm3cZMQ_e9_rNfs8zIKfr5Z5OuUa2kCLzmR2uBZbAAFf6vzOUukJT3UUL3D_94U3O2JI6OByEhbS5eNngNovCtDkUci4rQu5VvwmemDcFtHhf-exEIJ2hWaUz23BHuKAcNfZMsfj_4A?testcase_id=5887298756673536

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.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 5887298756673536 is verified as fixed, so closing issue.

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

Hi behdad - looks like the harfbuzz roll did fix this one. What do you think about merging that to M56 at this point? 

That will be for drott@ to decide.

Thoughts drott@?

Weighing issue severity vs. risks of skipping the Beta for the larger than usual HarfBuzz roll (https://chromium.googlesource.com/chromium/src/+/4cff0bd9837375a461d56f354b7bfe8858923722%5E%21/#F0), I would prefer not to manually merge this to stable. 

This bug has been closed for more than 14 weeks. Removing security view restrictions.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot