Source URL: https://x86.lol/generic/2024/09/23/user-shadow-stacks.html
Source: Hacker News
Title: Hardening C Against ROP: Getting CET Shadow Stacks Working
Feedly Summary: Comments
AI Summary and Description: Yes
Summary: This text elaborates on the use of CET (Control-flow Enforcement Technology) shadow stacks in Linux environments to enhance security by mitigating memory unsafety issues. It provides a practical guide on implementing this security feature for developers and security professionals.
Detailed Description: The text acts as a tutorial on setting up and using CET shadow stacks on Linux, which is critical for preventing return-oriented programming (ROP) attacks and other types of memory corruption vulnerabilities commonly found in software. Here are the significant points discussed:
– **CET Overview**:
– Control-flow Enforcement Technology (CET) is an essential security feature designed to mitigate memory unsafety vulnerabilities in software.
– **System Requirements**:
– To utilize CET shadow stacks, specific system requirements and configurations are needed:
– **Linux Version**: Requires Linux 6.6 or later with CONFIG_X86_USER_SHADOW_STACK enabled.
– **glibc Version**: Must be using version 2.39 or later.
– **CPU Compatibility**: Supported on CPUs like Intel Tiger Lake or later and AMD Zen 3 or later.
– **Toolchain**: GCC 8 or clang 7 or later is necessary for compiling programs with shadow stack support.
– **Implementation Steps**:
– A practical C program (`test.c`) is utilized in the explanation to simulate an ROP attack scenario.
– Instructions are provided for compiling the program with specific flags to enable shadow stack support (`-fcf-protection=return -o test`).
– The program is designed to demonstrate the impact of shadow stacks on a typical attack technique, such as stack smashing.
– **Testing the Configuration**:
– The text explains how to validate whether the binary correctly supports shadow stacks through commands like `readelf`.
– It highlights that shadow stacks are not enabled by default in glibc 2.39 and offers guidance on opting in using glibc tunable parameters.
Key Insights for Security Professionals:
– **Importance of Modern Security Features**: Implementing modern security technologies like CET is vital for protecting applications from sophisticated attacks, particularly those exploiting memory safety issues.
– **Practical Application**: The tutorial format shows how to effectively apply theoretical security concepts in real-world scenarios, which is important for developers.
– **Compatibility Awareness**: Awareness of system and CPU compatibility is crucial when deploying security technologies to ensure effectiveness.
Overall, this text serves as both an informative guide and a practical resource for professionals seeking to enhance the security posture of applications running on Linux systems.