Isolated Execution Environment for eBPF

Summary

The post below is an update on a research project sponsored by the eBPF Foundation. It is the first in a series of posts about this research. The post was prepared by Zhe Wang (Institute of Computing Technology, Chinese Academy of Sciences; wangzhe12@ict.ac.cn), and Patrick Peihua Zhang (WeChat, Tencent; patrickzhang2333@gmail.com). Read about the status of all the sponsored research projects in this post. 1. Project Overview eBPF has evolved into a foundational technology in the Linux kernel, powering diverse subsystems from networking to observability. To safeguard kernel integrity, BPF programs undergo static verification before execution. However, the eBPF verifier faces challenges—security vulnerabilities and inherent complexity—that undermine its reliability. In response, we propose a paradigm shift: redefining BPF programs as kernel-mode applications requiring dedicated isolation. This project introduces a novel execution environment designed to isolate BPF programs, offering an alternative architectural solution to enhance the security and scalability of eBPF infrastructure. We systematically analyzed the eBPF verifier’s objectives to achieve equivalent security guarantees. This post serves as the first installment in our series, providing a structured summary of the verifier’s security guarantees in Linux v6.16. We focus specifically on unprivileged programs, as their requirements subsume those of privileged programs. In subsequent blogs, we will discuss our design methodologies—including hardware-assisted and Software-Based Fault Isolation (SFI) approaches—alongside current milestones, challenges, and future directions. 2. Verifier Workflow Fig. 1 The workflow of the verifier. The workflow of the verifier consists of three consecutive stages, with the later stages becoming more complex. As shown in Fig.1, the pre-processing stage scans the BPF program linearly to find relocation items and check for any unallowed opcodes, e.g., indirect calls (calls). The C...