Allow TUN/TAP device access for container_engine_t

[lsm5]

OCP clusters upgraded from 4.17/4.18 to 4.20 get AVC denials for pasta operations in nested container mode.

Fixes: RHEL-131796

Summary by Sourcery

Bug Fixes:

• Resolve SELinux AVC denials when performing pasta networking operations in nested container mode after upgrading OCP clusters from 4.17/4.18 to 4.20.

[sourcery-ai]

Reviewer's guide (collapsed on small PRs)

Reviewer's Guide

Update SELinux policy for container_engine_t to allow TUN/TAP device access, resolving AVC denials for pasta operations in nested container mode after OCP upgrades to 4.20.

File-Level Changes

Change	Details	Files
Adjust SELinux policy for container_engine_t to permit TUN/TAP device usage needed by pasta in nested container setups.	Modify container.te to extend container_engine_t permissions to cover TUN/TAP device access (e.g., character device operations and related interfaces) Align policy changes with pasta’s usage patterns to eliminate AVC denials seen after upgrading OCP clusters to 4.20	container.te

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[gemini-code-assist]

Summary of Changes

Hello @lsm5, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses a critical issue in upgraded OCP clusters where pasta operations in nested container environments were failing due to SELinux AVC denials. By modifying the SELinux policy to allow the container engine to access TUN/TAP devices, the change ensures seamless network functionality for containers, preventing service disruptions and improving system stability.

Highlights

• SELinux Policy Update: The SELinux policy for container_engine_t has been updated to explicitly grant read and write access to TUN/TAP devices.
• AVC Denial Resolution: This change resolves AVC (Access Vector Cache) denials encountered during pasta operations in nested container mode on OpenShift Container Platform (OCP) clusters upgraded to versions 4.20 from 4.17/4.18.

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[lsm5]

@rhatdan @haircommander @cgruver PTAL

[gemini-code-assist]

Code Review

This pull request adds a SELinux rule to allow the container_engine_t domain to access TUN/TAP devices. The change, which involves adding the corenet_rw_tun_tap_dev macro call, is a direct and appropriate fix for the described AVC denials related to pasta operations in nested container mode. The new rule is correctly placed within the existing policy structure for container_engine_t. The change is sound and I have no further recommendations.

[haircommander]

LGTM

[packit-as-a-service]

Tests failed. @containers/packit-build please check.

[sourcery-ai]

Hey there - I've reviewed your changes and they look great!

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[lsm5]

The AVC denials on ELN and rawhide aarch64 seem to be selinux-policy related. Failing on #430 as well.

[lsm5]

I think we can merge this once we have final confirmation from @cgruver