Update OSS-Fuzz integration

[correctmost]

Description

An OSS-Fuzz integration was set up for astroid last year. The build has been failing for a few months and it seems to lack active maintenance.

Would you mind if I fixed the build and assigned myself as a co-maintainer? I maintain the librsvg integration and I am familiar with the OSS-Fuzz platform.

Having a functioning OSS-Fuzz integration could help catch regressions on the main branch before releases are tagged.

Action items

1. Fix the build by pinning the version to astroid 3.2.4 for now
   • The OSS-Fuzz images are currently stuck on Python 3.8, but there is work being done to support 3.10
     
   • Fixing the build now will allow the corpus to grow, which will benefit future runs against main (once Python 3.10 support lands)
2. Add myself to the list of people who are automatically CC'd on astroid bug reports

Considerations

1. Are any of the current maintainers interested in being set as the primary contact for the OSS-Fuzz integration?
   • To get full access to the system, you will need a Google/Gmail account
     • Note: The associated email address will be listed in the OSS-Fuzz repo without any obfuscation (example)
   • Other maintainers can also be automatically CC'd, but there can only be one primary
2. OSS-Fuzz can generate a decent amount of bug reports
   • I can help triage the issues, but some maintainers do not want to get notifications from a totally separate system
3. Updating the astroid project files on OSS-Fuzz requires the signing of a Google CLA
   • I have already signed the CLA, so I can help with PRs if you are uncomfortable with that process
4. Google offers monetary rewards for improving the code coverage of existing integrations. I am interested in fixing the build and helping maintain the integration independently of that, but I also have ideas for increasing coverage that might qualify for said rewards.

Google has documentation for the OSS-Fuzz system, but I can also help answer any questions. Thanks!

[jacobtylerwalls]

Thanks for this @correctmost, I'll ask around and get an answer on the primary contact, but I anticipate that the answers to your other questions will be "for sure".

[jacobtylerwalls]

I got a response from @Pierre-Sassoulas that it's okay to list me (@jacobtylerwalls) as primary: jacobtylerwalls [ at ] gmail.com

Would you mind if I fixed the build and assigned myself as a co-maintainer?

Yes, go ahead, and thanks for the help!

[correctmost]

Awesome, thanks! I submitted a PR to fix the build and update the maintainers list:

• astroid: fix build and update maintainers google/oss-fuzz#12386

[correctmost]

The OSS-Fuzz PR was merged, so you should now have access to the following items with your Google account:

• The OSS-Fuzz dashboard
• An overview page of all crashes and hangs/timeouts
• Existing bug reports that were filed automatically for the items on the overview page

If you don't have access yet, it may take a day or two for everything to sync.

We also got CC'd on ~15 existing bug reports. Here's my plan for those:

• Let the automated reproduction tasks run tomorrow with a fixed build
  • The build was not fixed for today's run (8-21) because the PR got merged after the run
• Triage any reports that are still marked as reproducible to see if the bug still exists on main

This is my overall plan for the integration:

• Verify access to the system
• Triage all existing reports
• Submit developer docs to the astroid (or Pylint) repo
  • I wrote an OSS-Fuzz developer guide for librsvg that I will adapt
• Increase coverage after a steady state has been reached with the triage efforts

Let me know if you encounter any issues!

[correctmost]

Updates for the above tasks:

Verify access to the system

Hopefully you have access now :)

Triage all existing reports

All issues have been triaged. Here's the full list of bugs:

• IndexError when _alias() has no arguments  #2513
• KeyError in _set_proxied with getset_descriptor class #2517
• "TypeError: 'UninferableBase' object is not iterable" when inferring random.sample code #2518
• ValueError when stringifying namedtuple exception that contains invalid format string #2519
• RecursionError with hundreds of consecutive unary operators #2520
• OverflowError in _multiply_seq_by_int #2521
• "TypeError: unhashable type: 'dict'" when comparing invalid dict literal #2522
• MemoryError in _multiply_seq_by_int when constructing large list #2523
• RecursionError with hundreds of consecutive binary operations #2524
• RecursionError with hundreds of consecutive function calls #2525
• RecursionError with hundreds of consecutive type comments #2526
• Uncaught TokenError while fuzzing #2527

Submit developer docs to the astroid (or Pylint) repo

PR submitted: pylint-dev/pylint#9896

Increase coverage after a steady state has been reached with the triage efforts

Coverage builds are currently broken. I am trying to get more debug info with this PR: google/oss-fuzz#12502.

I will revisit this item after the coverage builds are fixed.

[correctmost]

Coverage builds are currently broken. I am trying to get more debug info with this PR: google/oss-fuzz#12502.

Coverage builds were fixed by these changes:

• Fix crashes with large positive and negative list multipliers #2596
• Fix OverflowError with empty list and large multiplier #2597
• astroid: fix coverage builds google/oss-fuzz#12558

I submitted an additional PR to try to increase coverage, which is currently at 66%:

• astroid: add seed corpus of .py files for fuzz_parse target google/oss-fuzz#12563

Remaining work:

• Triage any new issues that get uncovered by the additional coverage
• Try to upgrade past Python 3.8 on OSS-Fuzz
  • [infra] Upgrade Python to 3.10.14 in base-builder & base-runner Images google/oss-fuzz#12027 is still pending
  • It might also be possible to manually upgrade the astroid project to 3.9, which would allow us to fuzz against main again