Messages in this thread | | | From | Kees Cook <> | Date | Wed, 22 Feb 2017 10:46:30 -0800 | Subject | Re: [PATCH v3 0/4] Improved seccomp logging |
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On Thu, Feb 16, 2017 at 3:29 PM, Kees Cook <keescook@chromium.org> wrote: > On Wed, Feb 15, 2017 at 7:24 PM, Andy Lutomirski <luto@amacapital.net> wrote: >> On Mon, Feb 13, 2017 at 7:45 PM, Tyler Hicks <tyhicks@canonical.com> wrote: >>> This patch set is the third revision of the following two previously >>> submitted patch sets: >>> >>> v1: http://lkml.kernel.org/r/1483375990-14948-1-git-send-email-tyhicks@canonical.com >>> v1: http://lkml.kernel.org/r/1483377999-15019-2-git-send-email-tyhicks@canonical.com >>> >>> v2: http://lkml.kernel.org/r/1486100262-32391-1-git-send-email-tyhicks@canonical.com >>> >>> The patch set aims to address some known deficiencies in seccomp's current >>> logging capabilities: >>> >>> 1. Inability to log all filter actions. >>> 2. Inability to selectively enable filtering; e.g. devs want noisy logging, >>> users want relative quiet. >>> 3. Consistent behavior with audit enabled and disabled. >>> 4. Inability to easily develop a filter due to the lack of a >>> permissive/complain mode. >> >> I think I dislike this, but I think my dislikes may be fixable with >> minor changes. >> >> What I dislike is that this mixes app-specific built-in configuration >> (seccomp) with global privileged stuff (audit). The result is a >> potentially difficult to use situation in which you need to modify an >> app to make it loggable (using RET_LOG) and then fiddle with >> privileged config (auditctl, etc) to actually see the logs. > > You make a good point about RET_LOG vs log_max_action. I think making > RET_LOG the default value would work for 99% of the cases.
Actually, I take this back: making "log" the default means that everything else gets logged too, include "expected" return values like errno, trap, etc. I think that would be extremely noisy as a default (for upstream or Ubuntu).
Perhaps RET_LOG should unconditionally log? Or maybe the logged actions should be a bit field instead of a single value? Then the default could be "RET_KILL and RET_LOG", but an admin could switch it to just RET_KILL, or even nothing at all? Hmmm...
-Kees
-- Kees Cook Pixel Security
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