From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE217C38142 for ; Fri, 27 Jan 2023 22:56:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230195AbjA0W4W (ORCPT ); Fri, 27 Jan 2023 17:56:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231287AbjA0W4U (ORCPT ); Fri, 27 Jan 2023 17:56:20 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5A1379633 for ; Fri, 27 Jan 2023 14:55:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674860115; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=TBTNNrJ5H6EIuuMcTERsk2lhrSBPK+9yag5Mpha8Oo4=; b=WiIbe+b1ma/IziK5e+7w3RjK3SCZQ9Yd10fnW8a3n2/v5FBIXAzWA8HonIsH5vpkBVv8EI gOYsHsVav7SUgWN0TY451M3zLmztHaAAZUh6YE+41zbWc/8/q774GM1txkb7/4kq2W+3RB jH6nCiN/eew8XRjDzcDIP3NNHj2QoAk= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-57-zpUWEGnYOdO8AhFhqMBwyw-1; Fri, 27 Jan 2023 17:55:10 -0500 X-MC-Unique: zpUWEGnYOdO8AhFhqMBwyw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9035229AA3B3; Fri, 27 Jan 2023 22:55:09 +0000 (UTC) Received: from madcap2.tricolour.ca (ovpn-0-3.rdu2.redhat.com [10.22.0.3]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F05D318EC1; Fri, 27 Jan 2023 22:55:07 +0000 (UTC) Date: Fri, 27 Jan 2023 17:55:05 -0500 From: Richard Guy Briggs To: Paul Moore Cc: Linux-Audit Mailing List , LKML , io-uring@vger.kernel.org, Eric Paris , Steve Grubb , Stefan Roesch , Christian Brauner , Jens Axboe , Pavel Begunkov Subject: Re: [PATCH v1 1/2] io_uring,audit: audit IORING_OP_FADVISE but not IORING_OP_MADVISE Message-ID: References: <68eb0c2dd50bca1af91203669f7f1f8312331f38.1674682056.git.rgb@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 2023-01-27 17:35, Paul Moore wrote: > On Fri, Jan 27, 2023 at 12:24 PM Richard Guy Briggs wrote: > > > > Since FADVISE can truncate files and MADVISE operates on memory, reverse > > the audit_skip tags. > > > > Fixes: 5bd2182d58e9 ("audit,io_uring,io-wq: add some basic audit support to io_uring") > > Signed-off-by: Richard Guy Briggs > > --- > > io_uring/opdef.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/io_uring/opdef.c b/io_uring/opdef.c > > index 3aa0d65c50e3..a2bf53b4a38a 100644 > > --- a/io_uring/opdef.c > > +++ b/io_uring/opdef.c > > @@ -306,12 +306,12 @@ const struct io_op_def io_op_defs[] = { > > }, > > [IORING_OP_FADVISE] = { > > .needs_file = 1, > > - .audit_skip = 1, > > .name = "FADVISE", > > .prep = io_fadvise_prep, > > .issue = io_fadvise, > > }, > > I've never used posix_fadvise() or the associated fadvise64*() > syscalls, but from quickly reading the manpages and the > generic_fadvise() function in the kernel I'm missing where the fadvise > family of functions could be used to truncate a file, can you show me > where this happens? The closest I can see is the manipulation of the > page cache, but that shouldn't actually modify the file ... right? I don't know. I was going on the advice of Steve Grubb. I'm looking for feedback, validation, correction, here. > > [IORING_OP_MADVISE] = { > > + .audit_skip = 1, > > .name = "MADVISE", > > .prep = io_madvise_prep, > > .issue = io_madvise, > > I *think* this should be okay, what testing/verification have you done > on this? One of the things I like to check is to see if any LSMs > might perform an access check and/or generate an audit record on an > operation, if there is a case where that could happen we should setup > audit properly. I did a very quick check of do_madvise() and nothing > jumped out at me, but I would be interested in knowing what testing or > verification you did here. No testing other than build/boot/audit-testsuite. You had a test you had developed that went through several iterations? > paul-moore.com - RGB -- Richard Guy Briggs Sr. S/W Engineer, Kernel Security, Base Operating Systems Remote, Ottawa, Red Hat Canada IRC: rgb, SunRaycer Voice: +1.647.777.2635, Internal: (81) 32635