From owner-freebsd-hackers Thu Sep 17 14:43:45 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA12888 for freebsd-hackers-outgoing; Thu, 17 Sep 1998 14:43:45 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from super-g.inch.com (super-g.com [207.240.140.161]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id OAA12727 for ; Thu, 17 Sep 1998 14:42:55 -0700 (PDT) (envelope-from spork@super-g.com) Received: from localhost (localhost [127.0.0.1]) by super-g.inch.com (8.8.8/8.8.5) with SMTP id RAA05734; Thu, 17 Sep 1998 17:41:19 -0400 (EDT) Date: Thu, 17 Sep 1998 17:41:19 -0400 (EDT) From: spork X-Sender: spork@super-g.inch.com To: John Polstra cc: bwithrow@BayNetworks.COM, hackers@FreeBSD.ORG Subject: Re: GDB modifies shared libraries? In-Reply-To: <199809171632.JAA11090@austin.polstra.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Actually I see someone has just posted Mr. Withrow's message to Bugtraq. Odd. He's hinting that it's a security issue, which I don't quite see. It could create some confusion though, I suppose. --- Charles Sprickman spork@super-g.com On Thu, 17 Sep 1998, John Polstra wrote: > In article <199809171409.KAA02717@tuva.engeast.baynetworks.com>, > Robert Withrow wrote: > > I was debugging a (large) program using GDB on an xterm (which > > prevented me from getting the exact text, as you will see). This > > is on 2.2.6-RELEASE on a P6-200 with 128M ram. I was running as > > a normal user, not root. > > > > I issued the "run" command and GDB said that /usr/lib/libc.so.3.1 > > had changed and it was re-loading it. That was followed immediately > > by X freezing, and then a spontaneous re-boot. > > > > After the system re-booted, sure enough the date on /usr/lib/libc.so.3.1 > > had been changed! > > > > Now, with this program, GDB generally says that the *program* has changed > > *every* time I issue the "run" command, but I thought that was just a > > GDB problem. But I don't understand how GDB can override protections > > on /usr/lib/libc.so.3.1 in order to change its date. This seems like > > an OS bug. > > Yes, it is a kernel bug. As far as I know, it doesn't actually modify > the file -- it just "updates" it with its original contents, changing > the timestamp. > > The problem is believed to be solved in -current (and hence in 3.0). > At least, I haven't heard it reported there for a good long time. > However, I don't think anybody (except possibly John Dyson) knows > exactly what "the" fix was. > -- > John Polstra jdp@polstra.com > John D. Polstra & Co., Inc. Seattle, Washington USA > "Self-knowledge is always bad news." -- John Barth > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message