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From: Kees Cook <keescook@chromium.org>
Date: Fri, 11 Aug 2017 12:14:09 -0700
Message-ID: <CAGXu5jLFQpU62nVGPGXHGe0eQr=kEAmVDss18M2L4pLaUKUB3w@mail.gmail.com>
Subject: Re: [PATCH v6 0/6] Improved seccomp logging
To: Tyler Hicks <tyhicks@canonical.com>
Cc: Andy Lutomirski <luto@amacapital.net>, Will Drewry <wad@chromium.org>,
        Paul Moore <paul@paul-moore.com>, Eric Paris <eparis@redhat.com>,
        John Crispin <john@phrozen.org>, Tycho Andersen <tycho@docker.com>,
        linux-audit@redhat.com, LKML <linux-kernel@vger.kernel.org>,
        Linux API <linux-api@vger.kernel.org>
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On Thu, Aug 10, 2017 at 9:33 PM, Tyler Hicks <tyhicks@canonical.com> wrote:
> This patch set aims to improve logging in seccomp by:
>
>  1) Empowering administrators to be able to permit or quiet logging of
>     specific seccomp actions
>  2) Allowing applications to request logging of all actions, except for
>     RET_ALLOW, in the filter being loaded (subject to the
>     administrator's wishes in #1)
>  3) By making it possible for application developers to request logging
>     of specific syscalls while developing filters for their application
>     (subject to the administrator's wishes in #1)
>
> With this patch set applied, the logic for deciding if an action will be
> logged is as described in the commit message of the final patch.
>
> * Changes since v5:
>   - Rebase onto
>     https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/?h=seccomp/kill_process
>     (kees)
>     + Redefine the value of SECCOMP_FILTER_FLAG_LOG to account for the
>       new SECCOMP_FILTER_FLAG_KILL_PROCESS
>     + Add SECCOMP_FILTER_FLAG_KILL_PROCESS to the
>       detect_seccomp_filter_flags selftest
>   - Reorder patches to move SECCOMP_GET_ACTION_AVAIL patch behind
>     actions_avail sysctl patch (kees)
>   - Reorder patches to move the selftest to detect filter flag support
>     before the patch that adds SECCOMP_FILTER_FLAG_LOG (kees)
>   - Add psuedo code showing the high level logic of when and when not to
>     log to the commit message of each patch that changes the logging
>     behavior (inspired by kees)
>   - Add Suggested-by to the SECCOMP_GET_ACTION_AVAIL patch to credit
>     Andy for the idea (tyhicks)
>   - Use sizeof(seccomp_actions_avail), instead of strlen(), to avoid
>     variable length "names" array in seccomp_actions_logged_handler()
>     (smatch)
>   - Only check the actions_logged sysctl value for "kill" when first
>     introducing the actions_logged sysctl since filters cannot yet set
>     the FILTER_FLAG_LOG flag (kees)
>   - Mention how the actions_logged sysctl could quiet SECCOMP_RET_LOG
>     actions in seccomp_filter.rst documentation (kees)

Thanks! This looks good; I made some minor comment style adjustments,
and changed the rebase slightly (as I continue to agonize over how to
do KILL_PROCESS best...)

I'll get this sent to James for -next.

-Kees

-- 
Kees Cook
Pixel Security