From: Kees Cook <keescook@chromium.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>,
Alexei Starovoitov <ast@kernel.org>,
Djalal Harouni <tixxdz@gmail.com>,
Al Viro <viro@zeniv.linux.org.uk>,
"David S. Miller" <davem@davemloft.net>,
Daniel Borkmann <daniel@iogearbox.net>,
Greg KH <gregkh@linuxfoundation.org>,
"Luis R. Rodriguez" <mcgrof@kernel.org>,
Network Development <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
kernel-team <kernel-team@fb.com>,
Linux API <linux-api@vger.kernel.org>
Subject: Re: [PATCH net-next] modules: allow modprobe load regular elf binaries
Date: Thu, 8 Mar 2018 17:44:11 -0800 [thread overview]
Message-ID: <CAGXu5j+B4wgT3ovynAxa1zwCeROfN5zK45tL1FUnFh0sg8M5AA@mail.gmail.com> (raw)
In-Reply-To: <CA+55aFwJPDub+tdShCgeTz3UejeskVE7_x+eQLq75mCjYPyP8w@mail.gmail.com>
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
next prev parent reply other threads:[~2018-03-09 1:44 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-06 1:34 [PATCH net-next] modules: allow modprobe load regular elf binaries Alexei Starovoitov
2018-03-06 2:13 ` Randy Dunlap
2018-03-06 3:02 ` Alexei Starovoitov
2018-03-06 11:05 ` Greg KH
2018-03-07 1:07 ` Alexei Starovoitov
2018-03-07 3:24 ` Greg KH
2018-03-06 19:12 ` Linus Torvalds
2018-03-06 23:42 ` Chris Mason
2018-05-02 9:12 ` Jesper Dangaard Brouer
2018-03-06 20:01 ` Andy Lutomirski
2018-03-06 20:26 ` Linus Torvalds
2018-03-07 17:22 ` David Miller
2018-03-08 1:23 ` Luis R. Rodriguez
2018-03-08 23:07 ` Alexei Starovoitov
2018-03-09 1:58 ` Luis R. Rodriguez
2018-03-09 0:24 ` Kees Cook
2018-03-09 0:57 ` Alexei Starovoitov
2018-03-09 1:04 ` Andy Lutomirski
2018-03-09 1:25 ` Alexei Starovoitov
2018-03-09 1:24 ` Kees Cook
2018-03-09 0:59 ` Andy Lutomirski
2018-03-09 1:20 ` Alexei Starovoitov
2018-03-09 2:12 ` Andy Lutomirski
2018-03-09 2:31 ` David Miller
2018-03-09 3:10 ` Andy Lutomirski
2018-03-09 3:27 ` Alexei Starovoitov
2018-03-09 1:38 ` Linus Torvalds
2018-03-09 1:44 ` Kees Cook [this message]
2018-03-09 3:06 ` Linus Torvalds
2018-03-09 3:17 ` Linus Torvalds
2018-03-09 3:54 ` Andy Lutomirski
2018-03-09 5:08 ` Alexei Starovoitov
2018-03-09 15:16 ` Andy Lutomirski
2018-03-09 15:39 ` Alexei Starovoitov
2018-03-09 16:24 ` Andy Lutomirski
2018-03-09 17:32 ` Alexei Starovoitov
2018-03-09 18:15 ` Greg KH
2018-03-09 18:23 ` Andy Lutomirski
2018-03-09 18:29 ` Greg KH
2018-03-09 18:50 ` Alexei Starovoitov
2018-03-09 18:55 ` David Miller
2018-03-09 19:37 ` Andy Lutomirski
2018-03-10 1:43 ` Alexei Starovoitov
2018-03-11 2:17 ` Andy Lutomirski
2018-03-09 18:17 ` Linus Torvalds
2018-03-09 18:35 ` David Miller
2018-03-09 18:43 ` Kees Cook
2018-03-09 18:50 ` Linus Torvalds
2018-03-09 18:54 ` Kees Cook
2018-03-09 18:58 ` Alexei Starovoitov
2018-03-12 12:02 ` Edward Cree
2018-03-12 17:49 ` Alexei Starovoitov
2018-03-09 18:48 ` Andy Lutomirski
2018-03-09 18:53 ` Linus Torvalds
2018-03-09 18:57 ` David Miller
2018-03-09 19:12 ` Linus Torvalds
2018-03-09 19:38 ` Linus Torvalds
2018-03-09 19:45 ` Andy Lutomirski
2018-03-10 2:34 ` Alexei Starovoitov
2018-03-10 14:08 ` Luis R. Rodriguez
2018-03-10 15:16 ` Luis R. Rodriguez
2018-03-10 15:34 ` Luis R. Rodriguez
2018-03-12 17:22 ` Alexei Starovoitov
2018-03-13 8:48 ` Greg Kroah-Hartman
2018-03-22 20:54 ` Luis R. Rodriguez
2018-03-22 22:15 ` Andy Lutomirski
2018-03-22 22:21 ` Alexei Starovoitov
2018-03-23 2:47 ` Luis R. Rodriguez
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAGXu5j+B4wgT3ovynAxa1zwCeROfN5zK45tL1FUnFh0sg8M5AA@mail.gmail.com \
--to=keescook@chromium.org \
--cc=ast@kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=gregkh@linuxfoundation.org \
--cc=kernel-team@fb.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=mcgrof@kernel.org \
--cc=netdev@vger.kernel.org \
--cc=tixxdz@gmail.com \
--cc=torvalds@linux-foundation.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).