Re: [PATCH v2 net-next 0/3] bpf: unprivileged

From	David Miller <davem@davemloft.net>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 net-next 0/3] bpf: unprivileged
Date	2015-10-13 04:10 +0200
Message-ID	<qiXcm-GI-5@gated-at.bofh.it> (permalink)
References	<qhbWa-2nw-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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From: Alexei Starovoitov <ast@plumgrid.com>
Date: Wed,  7 Oct 2015 22:23:20 -0700

> v1-v2:
> - this set logically depends on cb patch
>   "bpf: fix cb access in socket filter programs":
>   http://patchwork.ozlabs.org/patch/527391/
>   which is must have to allow unprivileged programs.
>   Thanks Daniel for finding that issue.
> - refactored sysctl to be similar to 'modules_disabled'
> - dropped bpf_trace_printk
> - split tests into separate patch and added more tests
>   based on discussion
> 
> v1 cover letter:
> I think it is time to liberate eBPF from CAP_SYS_ADMIN.
> As was discussed when eBPF was first introduced two years ago
> the only piece missing in eBPF verifier is 'pointer leak detection'
> to make it available to non-root users.
> Patch 1 adds this pointer analysis.
> The eBPF programs, obviously, need to see and operate on kernel addresses,
> but with these extra checks they won't be able to pass these addresses
> to user space.
> Patch 2 adds accounting of kernel memory used by programs and maps.
> It changes behavoir for existing root users, but I think it needs
> to be done consistently for both root and non-root, since today
> programs and maps are only limited by number of open FDs (RLIMIT_NOFILE).
> Patch 2 accounts program's and map's kernel memory as RLIMIT_MEMLOCK.
> 
> Unprivileged eBPF is only meaningful for 'socket filter'-like programs.
> eBPF programs for tracing and TC classifiers/actions will stay root only.
> 
> In parallel the bpf fuzzing effort is ongoing and so far
> we've found only one verifier bug and that was already fixed.
> The 'constant blinding' pass also being worked on.
> It will obfuscate constant-like values that are part of eBPF ISA
> to make jit spraying attacks even harder.

Scary stuff, but I don't see any major problems, so series applied!
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[PATCH v2 net-next 0/3] bpf: unprivileged Alexei Starovoitov <ast@plumgrid.com> - 2015-10-08 07:30 +0200
  [PATCH v2 net-next 3/3] bpf: add unprivileged bpf tests Alexei Starovoitov <ast@plumgrid.com> - 2015-10-08 07:30 +0200
    Re: [PATCH v2 net-next 3/3] bpf: add unprivileged bpf tests Kees Cook <keescook@chromium.org> - 2015-10-08 19:50 +0200
      Re: [PATCH v2 net-next 3/3] bpf: add unprivileged bpf tests Alexei Starovoitov <ast@plumgrid.com> - 2015-10-08 20:00 +0200
  [PATCH v2 net-next 1/3] bpf: enable non-root eBPF programs Alexei Starovoitov <ast@plumgrid.com> - 2015-10-08 07:30 +0200
    Re: [PATCH v2 net-next 1/3] bpf: enable non-root eBPF programs Kees Cook <keescook@chromium.org> - 2015-10-08 19:50 +0200
    Re: [PATCH v2 net-next 1/3] bpf: enable non-root eBPF programs Hannes Frederic Sowa <hannes@stressinduktion.org> - 2015-10-08 20:30 +0200
      Re: [PATCH v2 net-next 1/3] bpf: enable non-root eBPF programs Alexei Starovoitov <ast@plumgrid.com> - 2015-10-09 00:10 +0200
        Re: [PATCH v2 net-next 1/3] bpf: enable non-root eBPF programs Hannes Frederic Sowa <hannes@stressinduktion.org> - 2015-10-09 13:50 +0200
          Re: [PATCH v2 net-next 1/3] bpf: enable non-root eBPF programs Alexei Starovoitov <ast@plumgrid.com> - 2015-10-09 19:40 +0200
            Re: [PATCH v2 net-next 1/3] bpf: enable non-root eBPF programs Daniel Borkmann <daniel@iogearbox.net> - 2015-10-09 19:50 +0200
              Re: [PATCH v2 net-next 1/3] bpf: enable non-root eBPF programs Alexei Starovoitov <ast@plumgrid.com> - 2015-10-09 20:00 +0200
      Re: [PATCH v2 net-next 1/3] bpf: enable non-root eBPF programs Thomas Graf <tgraf@suug.ch> - 2015-10-09 11:30 +0200
  Re: [PATCH v2 net-next 0/3] bpf: unprivileged David Miller <davem@davemloft.net> - 2015-10-13 04:10 +0200

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