From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757229AbdACF5S (ORCPT ); Tue, 3 Jan 2017 00:57:18 -0500 Received: from mail-vk0-f47.google.com ([209.85.213.47]:33723 "EHLO mail-vk0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757166AbdACF5K (ORCPT ); Tue, 3 Jan 2017 00:57:10 -0500 MIME-Version: 1.0 In-Reply-To: References: <1483375990-14948-1-git-send-email-tyhicks@canonical.com> From: Andy Lutomirski Date: Mon, 2 Jan 2017 21:56:48 -0800 Message-ID: Subject: Re: [PATCH 0/2] Begin auditing SECCOMP_RET_ERRNO return actions To: Paul Moore Cc: Tyler Hicks , Eric Paris , Kees Cook , Will Drewry , linux-audit@redhat.com, "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 2, 2017 at 2:47 PM, Paul Moore wrote: > On Mon, Jan 2, 2017 at 11:53 AM, Tyler Hicks wrote: >> This patch set creates the basis for auditing information specific to a given >> seccomp return action and then starts auditing SECCOMP_RET_ERRNO return >> actions. The audit messages for SECCOMP_RET_ERRNO return actions include the >> errno value that will be returned to userspace. > > I'm replying to this patchset posting because it his my inbox first, > but my comments here apply to both this patchset and the other > seccomp/audit patchset you posted. > > In my experience, we have two or three problems (the count varies > depending on perspective) when it comes to seccomp filter reporting: > > 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. > > My current thinking - forgive me, this has been kicking around in my > head for the better part of six months (longer?) and I haven't > attempted to code it up - is to create a sysctl knob for a system wide > seccomp logging threshold that would be applied to the high 16-bits of > *every* triggered action: if the action was at/below the threshold a > record would be emitted, otherwise silence. This should resolve > problems #1 and #2, and the code should be relatively straightforward > and small. > > As part of the code above, I expect that all seccomp logging would get > routed through a single logging function (sort of like a better > implementation of the existing audit_seccomp()) that would check the > threshold and trigger the logging if needed. This function could be > augmented to check for CONFIG_AUDIT and in the case where audit was > not built into the kernel, a simple printk could be used to log the > seccomp event; solving problem #3. Would this not be doable with a seccomp tracepoint and a BPF filter? --Andy