From owner-freebsd-security Tue Jun 30 02:37:19 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id CAA13289 for freebsd-security-outgoing; Tue, 30 Jun 1998 02:37:19 -0700 (PDT) (envelope-from owner-freebsd-security@FreeBSD.ORG) Received: from hydrogen.nike.efn.org (resnet.uoregon.edu [128.223.144.32]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id CAA13253 for ; Tue, 30 Jun 1998 02:36:55 -0700 (PDT) (envelope-from gurney_j@efn.org) Received: (from jmg@localhost) by hydrogen.nike.efn.org (8.8.8/8.8.7) id CAA28972; Tue, 30 Jun 1998 02:36:43 -0700 (PDT) Message-ID: <19980630023639.02857@hydrogen.nike.efn.org> Date: Tue, 30 Jun 1998 02:36:39 -0700 From: John-Mark Gurney To: andrewr Cc: Christoph Kukulies , freebsd-security@FreeBSD.ORG Subject: Re: xlock References: <199806290632.IAA00836@gilberto.physik.RWTH-Aachen.DE> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.69 In-Reply-To: ; from andrewr on Mon, Jun 29, 1998 at 08:27:49AM -0400 Reply-To: John-Mark Gurney Organization: Cu Networking X-Operating-System: FreeBSD 2.2.6-STABLE i386 X-PGP-Fingerprint: B7 EC EF F8 AE ED A7 31 96 7A 22 B3 D8 56 36 F4 X-Files: The truth is out there X-URL: http://resnet.uoregon.edu/~gurney_j/ Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org andrewr scribbled this message on Jun 29: > Also, I am porting a console locking program (doesn't allow VT switching), > from linux, but I have been having trouble with the actual stopping of the > allowing of VT switching. I have tried setting vtmode to be handled by > the process, then using an ioctl to execute this. This failed. Then, I > tried using flock(), that failed. If you have any ideas and would like to > know what I did before (dealing with flock() and ioctl(), just ask). I have modifications to lock that does this... it really isn't hard... you just simply modify the relsig of vt_mode to a signal, and simply ignore the signal... syscons will only switch away when you tell it that it can... this is how X restores the video mode for syscons... > On Mon, 29 Jun 1998, Christoph Kukulies wrote: > > > > > Alarmed by recent buffer overflow attacks on Linux machines in > > my vicinity (an exploit for this is available) I thought about > > xlock under FreeBSD and would like to know whether the > > security hole has been sorted out under FreeBSD 2.2.x or what > > measures are advised to prevent it. p.s. why do people not spend the 2 seconds it takes to remove sigs?? -- John-Mark Gurney Voice: +1 541 683 7109 Cu Networking P.O. Box 5693, 97405 Live in Peace, destroy Micro$oft, support free software, run FreeBSD Don't trust anyone you don't have the source for To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe security" in the body of the message