[AutoPR- Security] Patch coredns for CVE-2025-68156 [HIGH]

[azurelinux-security]

Auto Patch coredns for CVE-2025-68156.

Autosec pipeline run -> https://dev.azure.com/mariner-org/mariner/_build/results?buildId=1008162&view=results

Merge Checklist

All boxes should be checked before merging the PR (just tick any boxes which don't apply to this PR)

• The toolchain has been rebuilt successfully (or no changes were made to it)
• The toolchain/worker package manifests are up-to-date
• Any updated packages successfully build (or no packages were changed)
• Packages depending on static components modified in this PR (Golang, *-static subpackages, etc.) have had their Release tag incremented.
• Package tests (%check section) have been verified with RUN_CHECK=y for existing SPEC files, or added to new SPEC files
• All package sources are available
• cgmanifest files are up-to-date and sorted (./cgmanifest.json, ./toolkit/scripts/toolchain/cgmanifest.json, .github/workflows/cgmanifest.json)
• LICENSE-MAP files are up-to-date (./LICENSES-AND-NOTICES/SPECS/data/licenses.json, ./LICENSES-AND-NOTICES/SPECS/LICENSES-MAP.md, ./LICENSES-AND-NOTICES/SPECS/LICENSE-EXCEPTIONS.PHOTON)
• All source files have up-to-date hashes in the *.signatures.json files
• sudo make go-tidy-all and sudo make go-test-coverage pass
• Documentation has been updated to match any changes to the build system
• Ready to merge

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Summary

What does the PR accomplish, why was it needed?

• Auto Patch coredns for CVE-2025-68156 (HIGH).

Change Log

• CVE-2025-68156

Does this affect the toolchain?

YES/NO

Associated issues

• N/A

Links to CVEs

• https://nvd.nist.gov/vuln/detail/CVE-2025-68156

Test Methodology

• Pipeline build id: Buddy Build URL

[akhila-guruju]

AI backport was good.
In builtin/builtin.go,
there is no builtin function flatten. So, backport patch doesn't contain the upstream patched lines for this function.

In builtin/lib.go
there is no func flatten. So, backport patch doesn't contain the upstream patched lines for this function.

the vendor file builtin_test.go is not present in azl source tarball.

[Kanishk-Bansal]

/azurepipeline run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[jslobodzian]

@akhila-guruju and @Kanishk-Bansal I see that this patch originated from the upstream, but this is a terrible solution. Limiting regression to a depth to10000 mitigates, but it really isn't a solution because what to prevent the stack from blowing out at a depth of 5000 or 1000? I think we should work with MSRC or maybe the upstream on this. Golang should cause a stack overflow panic which will terminate the recursion. Maybe this exception should be caught instead and then have that returned as an error?

[jslobodzian]

This fix seems a little underdeveloped to me. It IS a mitigation, but not a solution.

[jslobodzian]

Does coredns need to change to set this to a smaller value?

[CBL-Mariner-Bot]

Auto cherry-pick results:

• 3.0-dev ✅ -> [AUTO-CHERRYPICK] [AutoPR- Security] Patch coredns for CVE-2025-68156 [HIGH] - branch 3.0-dev #15397

Auto cherry-pick pipeline run -> https://dev.azure.com/mariner-org/mariner/_build/results?buildId=1012833&view=results