Re: [PATCH v6 0/6] Improved seccomp logging

[Kees Cook]

On Thu, Aug 10, 2017 at 9:33 PM, Tyler Hicks <tyhicks@xxxxxxxxxxxxx> 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