Fix: address multiple minor bugs found during code audit

[vinayakjeet]

Description

Refactor error handling and nil-safety: use annotHypervisor in isRunning, remove nil error wrapping, fix consoleFile nil-deref, use errors.Is for sentinel checks, and propagate errors from getInitPid and deleteAllTCFilters.

Related issues

None

How was this tested?

lint and build

LLM usage

None

Checklist

• I have read the contribution guide.
• The linter passes locally (make lint).
• The e2e tests of at least one tool pass locally (make test_ctr, make test_nerdctl, make test_docker, make test_crictl).
• If LLMs were used: I have read the llm policy.

[netlify]

✅ Deploy Preview for urunc ready!

Name	Link
🔨 Latest commit	49a8488
🔍 Latest deploy log	https://app.netlify.com/projects/urunc/deploys/6995d98b9c06b00008f8b4ab
😎 Deploy Preview	https://deploy-preview-492--urunc.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[vinayakjeet]

hi @cmainas can you please review the changes .

[IrvingMg]

Some changes need to be reviewed, as they’re breaking unit tests and may not be actual bugs. You can run make unittest to verify that they pass.

[cmainas]

Changes look ok, but just a question. Where does "consoleFile nil-deref" take place?

[vinayakjeet]

@cmainas
The nil-deref is in pkg/unikontainers/rootfs.go, in prepareMonRootfs()
in original code did os.Create() with the guard if err != nil && !os.IsExist(err) — so if the file already existed, the error was skipped but consoleFile was still remains nil so consoleFile.Chmod() on the next line would panic.

[cmainas]

@cmainas The nil-deref is in pkg/unikontainers/rootfs.go, in prepareMonRootfs() in original code did os.Create() with the guard if err != nil && !os.IsExist(err) — so if the file already existed, the error was skipped but consoleFile was still remains nil so consoleFile.Chmod() on the next line would panic.

Yes, that is correct.

[vinayakjeet]

Hi @cmainas — I’ve rebased the PR onto the latest main. It should be good to go now 👍

[cmainas]

Thank you @vinayakjeet , please rebase once more to be on the safe side.

[vinayakjeet]

@cmainas rebased and updated — it's good to go now. Thanks