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 X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60D20C83004 for ; Wed, 29 Apr 2020 14:32:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4132621D82 for ; Wed, 29 Apr 2020 14:32:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="h8N/S0u6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726828AbgD2Ocf (ORCPT ); Wed, 29 Apr 2020 10:32:35 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:59335 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726355AbgD2Ocf (ORCPT ); Wed, 29 Apr 2020 10:32:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588170753; 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=NZ5MFDXotHZB03JKNrUMWgXgunYYuAen7GqrXpy/Jdg=; b=h8N/S0u62GXLJDa/LHL6YtX+hWbvKTJlf91bRs35XXGWMKRbwVjE/ZCWf8Cw7fjN8gJFis 2DlRxaJmlCASulb/m7vsT0FW7yat5jOJjZiJ5ubdNykjsG+2RKOWfKmcnCL40lHJYPTGF2 yRnttGnwEQ0h0oWa/fKD4gMHLfngEOg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-107-L-ni4mCuPB66h3atKQTxwA-1; Wed, 29 Apr 2020 10:32:30 -0400 X-MC-Unique: L-ni4mCuPB66h3atKQTxwA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9972E10A65C2; Wed, 29 Apr 2020 14:32:00 +0000 (UTC) Received: from madcap2.tricolour.ca (unknown [10.3.128.9]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8C66F5D9C9; Wed, 29 Apr 2020 14:31:49 +0000 (UTC) Date: Wed, 29 Apr 2020 10:31:46 -0400 From: Richard Guy Briggs To: Paul Moore Cc: Linux-Audit Mailing List , LKML , netfilter-devel@vger.kernel.org, sgrubb@redhat.com, omosnace@redhat.com, fw@strlen.de, twoerner@redhat.com, Eric Paris , ebiederm@xmission.com, tgraf@infradead.org Subject: Re: [PATCH ghak25 v4 3/3] audit: add subj creds to NETFILTER_CFG record to cover async unregister Message-ID: <20200429143146.3vlcmwvljo74ydb4@madcap2.tricolour.ca> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On 2020-04-28 18:25, Paul Moore wrote: > On Wed, Apr 22, 2020 at 5:40 PM Richard Guy Briggs wrote: > > Some table unregister actions seem to be initiated by the kernel to > > garbage collect unused tables that are not initiated by any userspace > > actions. It was found to be necessary to add the subject credentials to > > cover this case to reveal the source of these actions. A sample record: > > > > type=NETFILTER_CFG msg=audit(2020-03-11 21:25:21.491:269) : table=nat family=bridge entries=0 op=unregister pid=153 uid=root auid=unset tty=(none) ses=unset subj=system_u:system_r:kernel_t:s0 comm=kworker/u4:2 exe=(null) > > [I'm going to comment up here instead of in the code because it is a > bit easier for everyone to see what the actual impact might be on the > records.] > > Steve wants subject info in this case, okay, but let's try to trim out > some of the fields which simply don't make sense in this record; I'm > thinking of fields that are unset/empty in the kernel case and are > duplicates of other records in the userspace/syscall case. I think > that means we can drop "tty", "ses", "comm", and "exe" ... yes? >From the ghak28 discussion, this list and order was selected due to Steve's preference for the "kernel" record convention, so deviating from this will create yet a new field list. I'll defer to Steve on this. It also has to do with the searchability of fields if they are missing. I do agree that some fields will be superfluous in the kernel case. The most important field would be "subj", but then "pid" and "comm", I would think. Based on this contents of the "subj" field, I'd think that "uid", "auid", "tty", "ses" and "exe" are not needed. > While "auid" is a potential target for removal based on the > dup-or-unset criteria, I think it falls under Steve's request for > subject info here, even if it is garbage in this case. If we keep auid, I'd say keep ses, since they usually go together, though they are separated by another field in this "kernel" record field ordering. I expect this orphan record to occur so infrequently that I don't think bandwidth or space are a serious concern. > > Signed-off-by: Richard Guy Briggs > > --- > > kernel/auditsc.c | 18 ++++++++++++++++++ > > 1 file changed, 18 insertions(+) > > > > diff --git a/kernel/auditsc.c b/kernel/auditsc.c > > index d281c18d1771..d7a45b181be0 100644 > > --- a/kernel/auditsc.c > > +++ b/kernel/auditsc.c > > @@ -2557,12 +2557,30 @@ void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries, > > enum audit_nfcfgop op) > > { > > struct audit_buffer *ab; > > + const struct cred *cred; > > + struct tty_struct *tty; > > + char comm[sizeof(current->comm)]; > > > > ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_NETFILTER_CFG); > > if (!ab) > > return; > > audit_log_format(ab, "table=%s family=%u entries=%u op=%s", > > name, af, nentries, audit_nfcfgs[op].s); > > + > > + cred = current_cred(); > > + tty = audit_get_tty(); > > + audit_log_format(ab, " pid=%u uid=%u auid=%u tty=%s ses=%u", > > + task_pid_nr(current), > > + from_kuid(&init_user_ns, cred->uid), > > + from_kuid(&init_user_ns, audit_get_loginuid(current)), > > + tty ? tty_name(tty) : "(none)", > > + audit_get_sessionid(current)); > > + audit_put_tty(tty); > > + audit_log_task_context(ab); /* subj= */ > > + audit_log_format(ab, " comm="); > > + audit_log_untrustedstring(ab, get_task_comm(comm, current)); > > + audit_log_d_path_exe(ab, current->mm); /* exe= */ > > + > > audit_log_end(ab); > > } > > EXPORT_SYMBOL_GPL(__audit_log_nfcfg); > > -- > paul moore > www.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