From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it1-f195.google.com ([209.85.166.195]:35446 "EHLO mail-it1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726040AbeJLD7H (ORCPT ); Thu, 11 Oct 2018 23:59:07 -0400 Received: by mail-it1-f195.google.com with SMTP id p64-v6so15215684itp.0 for ; Thu, 11 Oct 2018 13:30:14 -0700 (PDT) MIME-Version: 1.0 References: <20181004203007.217320-1-mjg59@google.com> <20181004203007.217320-3-mjg59@google.com> <1539271386.11939.79.camel@linux.ibm.com> In-Reply-To: <1539271386.11939.79.camel@linux.ibm.com> From: Matthew Garrett Date: Thu, 11 Oct 2018 13:30:01 -0700 Message-ID: Subject: Re: [PATCH 2/3] IMA: Make use of filesystem-provided hashes To: zohar@linux.ibm.com Cc: linux-integrity , Dmitry Kasatkin , miklos@szeredi.hu, linux-fsdevel@vger.kernel.org, Alexander Viro Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Thu, Oct 11, 2018 at 8:23 AM Mimi Zohar wrote: > > On Thu, 2018-10-04 at 13:30 -0700, Matthew Garrett wrote: > > Some filesystems may be able to provide hashes in an out of band manner, > > and allowing them to do so is a performance win. This is especially true > > of FUSE-based filesystems where otherwise we recalculate the hash on > > every measurement. Make use of this by default, but provide a parameter > > to force recalculation rather than trusting the filesystem. > > > > Signed-off-by: Matthew Garrett > > Support for not calculating the file hash would need to be finer > grained than this, probably on a per mount basis. The default should > be for IMA to always calculate the file hash, unless explicitly told > not to. Ok, should this just be part of the IMA policy? > IMA should never skip the file hash calculation if the filesystem is > an untrusted mount (eg. SB_I_UNTRUSTED_MOUNTER). Ok.