Date: Sun, 30 Dec 2001 06:49:05 -0600 From: Randall Stewart <randall@stewart.chicago.il.us> To: Mike Silbersack <silby@silby.com> Cc: Bosko Milekic <bmilekic@technokratis.com>, net@FreeBSD.ORG Subject: Re: m_reclaim and a protocol drain Message-ID: <3C2F0D40.ADFE2B6F@stewart.chicago.il.us> References: <Pine.BSF.4.30.0112292352490.52452-100000@niwun.pair.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Mike Silbersack wrote: > > On Wed, 26 Dec 2001, Randall Stewart wrote: > > > This comment facinates me. The reason we made SACK's in SCTP > > revokeable is due to the potential DOS attack that someone > > can supposedly lauch if you don't allow the stack to revoke. > > > > I can actually see the reason that Sally made the comments > > and had us change it so that SACK's are revokeable. However > > you argue to the contrary and I wonder which is correct. > > > > If you do not allow revoking it is the same as if a protocol > > does not hold a drain() fucntion. A attacker could easily > > stuff a lot of out-of-order segments at you and thus > > fill up all your mbuf's or clusters (in my current testing > > case). This would then yeild a DOS since you could no longer > > receive any segments and leave you high and dry.... > > Heh, you nailed the reverse of the problem we've seen: Right now the easy > way to cause exhaustion is to fill up _send_ buffers, via netkill. I > guess if we solve that problem, out of order segments could be used for an > attack too. > Mike: Interesting problem.. but I was thinking in terms of a outside attacker.. not someone who has a login id on your machine. That leads down another path... i.e. local machine security. R > Just FWIW, > > Mike "Silby" Silbersack > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-net" in the body of the message -- Randall R. Stewart randall@stewart.chicago.il.us 815-342-5222 (cell phone) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3C2F0D40.ADFE2B6F>