From owner-svn-src-head@freebsd.org Mon May 15 19:36:10 2017 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 544CCD6EB1A; Mon, 15 May 2017 19:36:10 +0000 (UTC) (envelope-from danfe@freebsd.org) Received: from freefall.freebsd.org (freefall.freebsd.org [96.47.72.132]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "freefall.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 2FF9E17F5; Mon, 15 May 2017 19:36:10 +0000 (UTC) (envelope-from danfe@freebsd.org) Received: by freefall.freebsd.org (Postfix, from userid 1033) id 53E301C64; Mon, 15 May 2017 19:36:09 +0000 (UTC) Date: Mon, 15 May 2017 19:36:09 +0000 From: Alexey Dokuchaev To: Konstantin Belousov Cc: Ian Lepore , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r318313 - head/libexec/rtld-elf Message-ID: <20170515193609.GC28684@FreeBSD.org> References: <201705151848.v4FImwMW070221@repo.freebsd.org> <20170515185236.GB1637@FreeBSD.org> <20170515190030.GG1622@kib.kiev.ua> <1494875335.59865.118.camel@freebsd.org> <20170515192529.GH1622@kib.kiev.ua> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170515192529.GH1622@kib.kiev.ua> User-Agent: Mutt/1.7.1 (2016-10-04) X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 15 May 2017 19:36:10 -0000 On Mon, May 15, 2017 at 10:25:29PM +0300, Konstantin Belousov wrote: > On Mon, May 15, 2017 at 01:08:55PM -0600, Ian Lepore wrote: > > Well, for example, it seems like it would allow anyone to execute a > > binary even if the sysadmin had set it to -x specifically to prevent > > people from running it. > > The direct mode does not (and cannot) honor set{u,g}id modes of the > executable, so any binary run this way would only exercise the existing > power of the user which did it. > > The most advanced explanation that I was given in private was among > the lines: "if you have an environment where users can upload content > to a shared server, but have no access to chmod(2), no compilers, no > scripting languages, etc." The person then admitted that (s)he does not > consider it as an actual concern. Would this now allow executing binaries (with or without +x bit) from filesystems mounted with -o noexec? ./danfe