Model checking the BPF verifier by shunghsiyu

Project Description

BPF verifier plays a crucial role in securing the system (though less so now that unprivileged BPF is disabled by default in both upstream and SLES), and bugs in the verifier has lead to privilege escalation vulnerabilities in the past (e.g. CVE-2021-3490).

One way to check whether the verifer has bugs to use model checking (a formal verification technique), in other words, build a abstract model of how the verifier operates, and then see if certain condition can occur (e.g. incorrect calculation during value tracking of registers) by giving both the model and condition to a solver.

For the solver I will be using the Z3 SMT solver to do the checking since it provide a Python binding that's relatively easy to use.

Goal for this Hackweek

Learn how to use the Z3 Python binding (i.e. Z3Py) to build a model of (part of) the BPF verifier, probably the part that's related to value tracking using tristate numbers (aka tnum), and then check that the algorithm work as intended.

Resources

• Formal Methods for the Informal Engineer: Tutorial #1 - The Z3 Theorem Prover and its accompanying notebook is a great introduction into Z3
  • Has a section specifically on model checking
• Software Verification and Analysis Using Z3 a great example of using Z3 for model checking
• Sound, Precise, and Fast Abstract Interpretation with Tristate Numbers - existing work that use formal verification to prove that the multiplication helper used for value tracking work as intended
• [PATCH v5 net-next 00/12] bpf: rewrite value tracking in verifier - initial patch set that adds tristate number to the verifier

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OIDC Loginproxy by toe

Description

Reverse proxies can be a useful option to separate authentication logic from application logic. SUSE and openSUSE use "loginproxies" as an authentication layer in front of several services.

Currently, loginproxies exist which support LDAP authentication or SAML authentication.

Goals

The goal of this Hack Week project is, to create another loginproxy which supports OpenID Connect authentication which can then act as a drop-in replacement for the existing LDAP or SAML loginproxies.

Testing is intended to focus on the integration with OIDC IDPs from Okta, KanIDM and Authentik.

Resources

• #122254: Migrate away from login proxies to SSO

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VulnHeap by r1chard-lyu

Description

The VulnHeap project is dedicated to the in-depth analysis and exploitation of vulnerabilities within heap memory management. It focuses on understanding the intricate workflow of heap allocation, chunk structures, and bin management, which are essential to identifying and mitigating security risks.

Goals

• Familiarize with heap
  • Heap workflow
  • Chunk and bin structure
  • Vulnerabilities
• Vulnerability
  • Use after free (UAF)
  • Heap overflow
  • Double free
• Use Docker to create a vulnerable environment and apply techniques to exploit it

Resources

• https://heap-exploitation.dhavalkapil.com/divingintoglibc_heap
• https://raw.githubusercontent.com/cloudburst/libheap/master/heap.png
• https://github.com/shellphish/how2heap?tab=readme-ov-file

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Bot to identify reserved data leak in local files or when publishing on remote repository by mdati

Description

Scope here is to prevent reserved data or generally "unwanted", to be pushed and saved on a public repository, i.e. on Github, causing disclosure or leaking of reserved informations.

The above definition of reserved or "unwanted" may vary, depending on the context: sometime secret keys or password are stored in data or configuration files or hardcoded in source code and depending on the scope of the archive or the level of security, it can be either wanted, permitted or not at all.

As main target here, secrets will be registration keys or passwords, to be detected and managed locally or in a C.I. pipeline.

Goals

• Detection:

  • Local detection: detect secret words present in local files;
  • Remote detection: detect secrets in files, in pipelines, going to be transferred on a remote repository, i.e. via git push;

• Reporting:

  • report the result of detection on stderr and/or log files, noticed excluding the secret values.

• Acton:

  • Manage the detection, by either deleting or masking the impacted code or deleting/moving the file itself or simply notify it.

Resources

• Project repository, published on Github (link): m-dati/hkwk24;
• Reference folder: hkwk24/chksecret;
• First pull request (link): PR#1;
• Second PR, for improvements: PR#2;
• README.md and TESTS.md documentation files available in the repo root;
• Test subproject repository, for testing CI on push [TBD].

Notes

We use here some examples of secret words, that still can be improved.
The various patterns to match desired reserved words are written in a separated module, to be on demand updated or customized.

[Legend: TBD = to be done]

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Kanidm: A safe and modern IDM system by firstyear

Kanidm is an IDM system written in Rust for modern systems authentication. The github repo has a detailed "getting started" on the readme.

Kanidm Github

In addition Kanidm has spawn a number of adjacent projects in the Rust ecosystem such as LDAP, Kerberos, Webauthn, and cryptography libraries.

In this hack week, we'll be working on Quokca, a certificate authority that supports PKCS11/TPM storage of keys, issuance of PIV certificates, and ACME without the feature gatekeeping implemented by other CA's like smallstep.

For anyone who wants to participate in Kanidm, we have documentation and developer guides which can help.

I'm happy to help and share more, so please get in touch!

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