From owner-freebsd-security Fri Nov 30 23:33:12 2001 Delivered-To: freebsd-security@freebsd.org Received: from d150h247.resnet.uconn.edu (d150h247.resnet.uconn.edu [137.99.150.247]) by hub.freebsd.org (Postfix) with SMTP id BC35937B416 for ; Fri, 30 Nov 2001 23:33:09 -0800 (PST) Received: (qmail 52962 invoked by uid 1001); 1 Dec 2001 07:32:10 -0000 Date: Sat, 1 Dec 2001 02:32:10 -0500 From: "Peter C. Lai" To: Dave Cc: freebsd-security@freebsd.org Subject: Re: options USER_LDT Message-ID: <20011201023210.A52949@cowbert.2y.net> Reply-To: peter.lai@uconn.edu References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from mudman@R181172.resnet.ucsb.edu on Fri, Nov 30, 2001 at 11:33:12PM -0800 Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org IT's for the linux emulation module. Some linux ELF binaries require this to run. On Fri, Nov 30, 2001 at 11:33:12PM -0800, Dave wrote: > > I really have no clue what the kernel option: > options USER_LDT > > means, except this rugged definition I found in LINT (paraphrase): > "Allow applications running in user space to manipulate the Local > Descriptor Table (LDT)" > > Since it didn't come in the GENERIC (FBSD 4.4 REL), I'm assuming that > someone, somewhere, thought it would be a good idea to have this disabled > by default and maybe it was meant to be added in only by people who know > what they are doing. > > Is there a security risk by allowing programs to access the Local > Descriptor Table? (I'm not sure what the LDT is, but if it was off for a > reason I wouldn't want to challenge the decisions of those more informed > than myself. If it wasn't for an efficiency judgement, it could of been > for a security judgement) > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-security" in the body of the message -- Peter C. Lai University of Connecticut Dept. of Residential Life | Programmer Dept. of Molecular and Cell Biology | Undergraduate Research Assistant http://cowbert.2y.net/ 860.427.4542 203.206.3784 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message