Re: [LSF/MM/BPF TOPIC] eBPF isolation with pkeys

[Alexei Starovoitov <alexei.starovoitov@gmail.com>]

On Thu, Feb 12, 2026 at 8:24 AM Yeoreum Yun <yeoreum.yun@arm.com> wrote:
>
> Hi all,
>
> I would like to propose the topic of eBPF isolation with pkeys at the
> upcoming LSF/MM/BPF summit.
>
>
> Background
> ==========
>
> Today, eBPF programs provide powerful capabilities to extend kernel
> functionality without requiring modifications to the kernel itself.
> These capabilities are largely enabled by the eBPF verifier, which
> enforces memory safety and other constraints to protect the kernel.
>
> However, vulnerabilities in the verifier have repeatedly demonstrated that
> eBPF programs can also become a serious attack surface.  In several cases,
> flaws in verifier logic have allowed malicious eBPF programs to bypass
> safety guarantees and compromise kernel security.

eBPF was restricted to root for many years, so the above is simply not true.

> Representative CVEs include:
>
>      - CVE-2020-8835   [1]
>      - CVE-2021-3490   [2]
>      - CVE-2022-23222  [3]
>      - CVE-2023-2163   [4]

None of them are security issues. They're just bugs.
Like all those found by syzbot.

> An RFC series is planned for around Q2 2026, and the experimental
> implementations for eBPF isolation with pkey and pkey-aware memory
> allocators have already been completed internally.  Using these
> implementations, we verified that eBPF programs running under isolation
> successfully execute several sched_ext applications provided by
> tools/sched_ext, as well as some bpf kselftest cases.

The stated goal is wrong, hence not interested in patches
or discussion at lsfmm.

arm has a nice hw feature. Sure, but this is not a place to apply it.