From owner-freebsd-security Sun Sep 5 4:54:38 1999 Delivered-To: freebsd-security@freebsd.org Received: from janus.syracuse.net (janus.syracuse.net [205.232.47.15]) by hub.freebsd.org (Postfix) with ESMTP id E052C14DF7 for ; Sun, 5 Sep 1999 04:54:31 -0700 (PDT) (envelope-from green@FreeBSD.org) Received: from localhost (green@localhost) by janus.syracuse.net (8.9.3/8.8.7) with ESMTP id HAA87024; Sun, 5 Sep 1999 07:54:40 -0400 (EDT) X-Authentication-Warning: janus.syracuse.net: green owned process doing -bs Date: Sun, 5 Sep 1999 07:54:40 -0400 (EDT) From: "Brian F. Feldman" X-Sender: green@janus.syracuse.net To: Garrett Wollman Cc: freebsd-security@FreeBSD.org Subject: Re: FW: Local DoS in FreeBSD In-Reply-To: <199909050312.XAA26309@khavrinen.lcs.mit.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Sat, 4 Sep 1999, Garrett Wollman wrote: > < said: > > >> [I wrote:] > >> What's not clear is: > >> > >> 1) At what level do you impose this limit? > > > Resource limit, definitely. > > You totally missed the point. Did you mean at socket creation time/sb allocation time, or actual _usage_ when the mbufs are being taken up? > > >> 2) Should the limit be statistical or exact? > > > Well, I have it exact it would seem. > > So you clearly haven't actually thought about what the right answer > is. > > >> 3) What is a sensible default value? > > > Whatever's in login.conf? > > Not at all helpful. How about the size necessary for send + rcv space for a TCP socket * number of maximum user processes? > > > http://www.FreeBSD.org/~green/sbsize2.patch? The KASSERT() fails > > in some cases, which I need help tracking down. > > I think if you're not going to implement the Right Thing, there's no > sense adding all that complexity -- just make a per-socket limit, and > require the sysadmin to tune his kernel to match the resource limits > established. Err... But some users need lots of of file descriptors and/or processes. That would still leave this hole open. > > -GAWollman > > -- > Garrett A. Wollman | O Siem / We are all family / O Siem / We're all the same > wollman@lcs.mit.edu | O Siem / The fires of freedom > Opinions not those of| Dance in the burning flame > MIT, LCS, CRS, or NSA| - Susan Aglukark and Chad Irschick > -- Brian Fundakowski Feldman / "Any sufficiently advanced bug is \ green@FreeBSD.org | indistinguishable from a feature." | FreeBSD: The Power to Serve! \ -- Rich Kulawiec / To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message