From owner-freebsd-security@freebsd.org Sun May 30 13:43:17 2021 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 C3761655CA2 for ; Sun, 30 May 2021 13:43:17 +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 4FtKPc1GL8z4mRT for ; Sun, 30 May 2021 13:43:15 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from eg.sd.rdtc.ru (root@eg.sd.rdtc.ru [62.231.161.221] (may be forged)) by hz.grosbein.net (8.15.2/8.15.2) with ESMTPS id 14UDhAmm054555 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 30 May 2021 13:43:11 GMT (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: fasxmut@protonmail.com Received: from [10.58.0.10] (dadvw [10.58.0.10]) by eg.sd.rdtc.ru (8.16.1/8.16.1) with ESMTPS id 14UDh7ES065452 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Sun, 30 May 2021 20:43:07 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: sysrc (awk) bug To: Fas Xmut , "freebsd-security@freebsd.org" References: <0J-hkv9PO-ZfjHO2kiEVatVRNdz0xTZ8pDMOvPreE53RFRsgyWHnU0U1IPO-mxNmswiB5KyGgO067-gLMA0PfW4Py3bBYllvQCBMTc2T8QE=@protonmail.com> From: Eugene Grosbein Message-ID: Date: Sun, 30 May 2021 20:43:01 +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: <0J-hkv9PO-ZfjHO2kiEVatVRNdz0xTZ8pDMOvPreE53RFRsgyWHnU0U1IPO-mxNmswiB5KyGgO067-gLMA0PfW4Py3bBYllvQCBMTc2T8QE=@protonmail.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=1.6 required=5.0 tests=BAYES_00,LOCAL_FROM, NICE_REPLY_A,RDNS_NONE,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_PASS SPF: sender matches SPF record * 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record * 2.6 LOCAL_FROM From my domains * 1.9 RDNS_NONE Delivered to internal network by a host with no rDNS * -0.6 NICE_REPLY_A Looks like a legit reply (A) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on hz.grosbein.net X-Spam-Level: * X-Rspamd-Queue-Id: 4FtKPc1GL8z4mRT X-Spamd-Bar: / Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=fail (mx1.freebsd.org: domain of eugen@grosbein.net does not designate 2a01:4f8:c2c:26d8::2 as permitted sender) smtp.mailfrom=eugen@grosbein.net X-Spamd-Result: default: False [-0.10 / 15.00]; TO_DN_EQ_ADDR_SOME(0.00)[]; R_SPF_FAIL(1.00)[-all]; FREEFALL_USER(0.00)[eugen]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; ARC_NA(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[grosbein.net]; RBL_DBL_DONT_QUERY_IPS(0.00)[2a01:4f8:c2c:26d8::2:from]; NEURAL_SPAM_SHORT(1.00)[1.000]; SPAMHAUS_ZRD(0.00)[2a01:4f8:c2c:26d8::2:from:127.0.2.255]; RCVD_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; FREEMAIL_TO(0.00)[protonmail.com,freebsd.org]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:24940, ipnet:2a01:4f8::/32, country:DE]; RCVD_TLS_ALL(0.00)[]; MAILMAN_DEST(0.00)[freebsd-security] X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 30 May 2021 13:43:17 -0000 30.05.2021 11:36, Fas Xmut via freebsd-security wrote: > I don't know if it is a security bug or not. When I use sysrc today, the error operations emptied my /etc/rc.conf, that's a small disaster, because my /etc/rc.conf is updated day by day, but now, it is empty. > > First, change your default root shell to sh/ksh or their derived shell. (I have tested, csh will not trigger that bug). > > Second, backup /etc/rc.conf to any other place. > > Then do the following commands: > > ------------------------------------------------------------------------ > # sysrc something_enable="NO" > # sysrc something_enable="YES >> " > awk: newline in string YES > ... at source line 1 > something_enable: NO -> YES > ------------------------------------------------------------------------ > > Now see what is inside /etc/rc.conf ? Everything is empty! only one thing in it: > > ------------------------------------------------------------------------ > something_enable="YES > " > ------------------------------------------------------------------------ What is your FreeBSD version?