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    SubjectRe: [PATCH net-next] modules: allow modprobe load regular elf binaries
    On Thu, Mar 8, 2018 at 5:38 PM, Linus Torvalds
    <torvalds@linux-foundation.org> wrote:
    > On Thu, Mar 8, 2018 at 4:59 PM, Andy Lutomirski <luto@amacapital.net> wrote:
    >>
    >> Also, I don't see how this is any more exploitable than any other
    >> init_module().
    >
    > Absolutely. If Kees doesn't trust the files to be loaded, an
    > executable - even if it's running with root privileges and in the
    > initns - is still fundamentally weaker than a kernel module.
    >
    > So I don't understand the security argument AT ALL. It's nonsensical.
    > The executable loading does all the same security checks that the
    > module loading does, including the signing check.
    >
    > And the whole point is that we can now do things with building and
    > loading a ebpf rule instead of having a full module.

    My concerns are mostly about crossing namespaces. If a container
    triggers an autoload, the result runs in the init_ns. So, really,
    there's nothing new from my perspective, except that it's in userspace
    instead of in the kernel.

    Perhaps it's an orthogonal concern.

    -Kees

    --
    Kees Cook
    Pixel Security

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