From owner-freebsd-security@freebsd.org Sun May 17 00:29:18 2020 Return-Path: Delivered-To: freebsd-security@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id EEC492E1B9B for ; Sun, 17 May 2020 00:29:18 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from hz.grosbein.net (hz.grosbein.net [IPv6:2a01:4f8:c2c:26d8::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "hz.grosbein.net", Issuer "hz.grosbein.net" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 49Pjgx5Smmz3yNJ for ; Sun, 17 May 2020 00:29:17 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from eg.sd.rdtc.ru (eg.sd.rdtc.ru [IPv6:2a03:3100:c:13:0:0:0:5]) by hz.grosbein.net (8.15.2/8.15.2) with ESMTPS id 04H0SxWH036520 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 17 May 2020 00:28:59 GMT (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: ihor@antonovs.family Received: from [10.58.0.10] (dadvw [10.58.0.10]) by eg.sd.rdtc.ru (8.15.2/8.15.2) with ESMTPS id 04H0Sr1a057286 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Sun, 17 May 2020 07:28:53 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: Malicious root user sandboxing To: ihor@antonovs.family, freebsd-security@freebsd.org References: <1641188.rRC0nNcZtX@amos> From: Eugene Grosbein Message-ID: <442284bc-e137-f5de-aee6-1d5c69e7d3b8@grosbein.net> Date: Sun, 17 May 2020 07:28:46 +0700 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <1641188.rRC0nNcZtX@amos> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=0.3 required=5.0 tests=BAYES_00,LOCAL_FROM, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.2 X-Spam-Report: * -2.3 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record * -0.0 SPF_PASS SPF: sender matches SPF record * 2.6 LOCAL_FROM From my domains X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on hz.grosbein.net X-Rspamd-Queue-Id: 49Pjgx5Smmz3yNJ X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=permerror (mx1.freebsd.org: domain of eugen@grosbein.net uses mechanism not recognized by this client) smtp.mailfrom=eugen@grosbein.net X-Spamd-Result: default: False [-4.00 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; FROM_HAS_DN(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; TO_DN_NONE(0.00)[]; DMARC_NA(0.00)[grosbein.net]; RCVD_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_SOME(0.00)[]; R_SPF_PERMFAIL(0.00)[]; RCPT_COUNT_TWO(0.00)[2]; IP_SCORE(-1.90)[ip: (-5.32), ipnet: 2a01:4f8::/29(-2.67), asn: 24940(-1.47), country: DE(-0.02)]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:24940, ipnet:2a01:4f8::/29, country:DE]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_TLS_ALL(0.00)[] X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 17 May 2020 00:29:19 -0000 17.05.2020 7:02, Ihor Antonov wrote: > So far it seems that my endeavor is doomed. Any comments or suggestions are > appreciated. You'll need to write and test lots of kernel-level code to achieve this. I'd suggest you re-think your decision about jails because it seems jails can really be the solution if you combine jail with other system abilities. For example, sharing subtree with r/o access is easily achieved using read-only nullfs mount. Also, shared PAM does not mean duplication of system user database, take a look at: man -k pam_|fgrep '(8)' Usage of jails does not require any modification of the application. I did it for multiple setups and it works perfectly. As last resort, you may run nested FreeBSD system using bhyve(8).