From owner-freebsd-security@FreeBSD.ORG Thu Dec 29 18:36:15 2011 Return-Path: Delivered-To: freebsd-security@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E9D631065670; Thu, 29 Dec 2011 18:36:15 +0000 (UTC) (envelope-from ache@vniz.net) Received: from vniz.net (vniz.net [194.87.13.69]) by mx1.freebsd.org (Postfix) with ESMTP id 5C0C78FC15; Thu, 29 Dec 2011 18:36:14 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by vniz.net (8.14.5/8.14.5) with ESMTP id pBTIa75C048970; Thu, 29 Dec 2011 22:36:07 +0400 (MSK) (envelope-from ache@vniz.net) Received: (from ache@localhost) by localhost (8.14.5/8.14.5/Submit) id pBTIa7wc048969; Thu, 29 Dec 2011 22:36:07 +0400 (MSK) (envelope-from ache) Date: Thu, 29 Dec 2011 22:36:06 +0400 From: Andrey Chernov To: d@delphij.net Message-ID: <20111229183606.GA48785@vniz.net> Mail-Followup-To: Andrey Chernov , d@delphij.net, John Baldwin , freebsd-security@FreeBSD.ORG, Doug Barton References: <201112231500.pBNF0c0O071712@svn.freebsd.org> <4EF6444F.6090708@FreeBSD.org> <201112290939.53665.jhb@freebsd.org> <4EFCB0C9.6090608@delphij.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4EFCB0C9.6090608@delphij.net> User-Agent: Mutt/1.5.21 (2010-09-15) Cc: freebsd-security@FreeBSD.ORG, Doug Barton , John Baldwin Subject: Re: svn commit: r228843 - head/contrib/telnet/libtelnet head/crypto/heimdal/appl/telnet/libtelnet head/include head/lib/libc/gen head/lib/libc/iconv head/lib/libc/include head/lib/libc/net head/libexec... X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Dec 2011 18:36:16 -0000 On Thu, Dec 29, 2011 at 10:26:17AM -0800, Xin Li wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On 12/29/11 06:39, John Baldwin wrote: > > Can you give some more details on why ftpd is triggering a dlopen > > inside of the chroot? It would appear that that is unrelated to > > helper programs (since setting a flag in libc in ftpd can't > > possibly affect helper programs ability to use dlopen() from within > > libc). > > Sure. That's because nsdispatch(3) would reload /etc/nsswitch.conf if > it notices a change. After chroot() the file is considered as > "chang"ed and thus it reloads the file as well as designated shared > libraries. Another proposal more close to @secteam version, but less ugly: to have public API rtld function (or env variable) which prevents _any_ dlopen(), not guarded currently by libc only. That way only rtld and ftpd's needs to be rebuilded, but not libc itself. -- http://ache.vniz.net/