Analysis of the Security Posture of eBPF
eBPF is a technology that enables the execution of sandboxed programs in privileged context; the kernel of an operating system. It has its roots in the Linux kernel. The majority of the kernel’s components can be instrumented thanks to it. It may be used to improve the functionality of the kernel without changing its source code or importing kernel modules. eBPF gives the kernel programmability, enabling the Linux kernel to use an effective application deployment method.
Security is a major problem since eBPF enables applications to function in a privileged context. The employment of a verifier ensures this security. The system’s eBPF instructions are statically analyzed by the kernel’s verifier before being loaded. The verifier makes sure the program won’t enter an infinite loop, there are no dangerous memory accesses, and the complexity and code size are below the limit. The kernel source code’s implementation may be found in kernel/bpf/verifier.c . After this check by the verifier, the code is considered safe to run. These applications can then have access to kernel-only features like network traffic filtering, system call hooking, or tracing.
To sum up some use cases, eBPF is used a lot for the creation of certain tools like networking, monitoring, tracing and packet filtering tools. It might also be used for hotpatching, allowing the bug to be fixed immediately rather than interfering with other operations while a patch is applied. There are several risks, such the fact that eBPF applications have the ability to write to user-space memory. This can be exploited by malware to alter a process’s memory during syscalls. This gives the attacker rootkit capability. Overall, eBPF is an intriguing attack vector due of the ability to run kernel applications without requiring the loading of a kernel module. This characteristic could be exploited by attack vectors. In this research paper we have conducted an in-depth research on eBPF to develop a holistic understanding of eBPF and the related dangers and attack surfaces.
