From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Grubb Subject: Re: [PATCH 1/1] Fanotify: Introduce a permissive mode Date: Tue, 15 Aug 2017 12:23:08 -0400 Message-ID: <1667402.zHjUK3v2PR@x2> References: <3663877.NZSPRKlUQW@x2> <1515035.GaL8l3qfz8@x2> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org To: Amir Goldstein Cc: fsdevel , Linux Audit , Jan Kara List-Id: linux-audit@redhat.com On Tuesday, August 15, 2017 11:37:19 AM EDT Amir Goldstein wrote: > > So, there is some utility to having the application stopped so that the > > daemon can do its checks but then throw away the answer so that more of > > the policy can be verified. > > > >> *if* at all this method is acceptable overriding access decision should > >> probably be accompanied with pr_warn_ratelimited and a big warning > >> for fanotify_init with FAN_CLASS_{,PRE_}CONTENT priority. > > > > I was hoping the audit event was a big enough warning. But something for > > dmesg/syslog is easy to add. > > No warning is big enough if the change breaks existing apps behavior. > One of the major flaws in your suggestion is that it changes the behavior > globally. I think what you want for the debugging use case is to introduce > a new fanotify_init() flag FAN_PERMISSIVE. > Your daemon could set the new flag to opt-in for the new behavior, which > may depend on kernel parameter, or even on sysfs knob if you like. Thanks for the discussion. I'm self-NAK'ing this for now. -Steve