Date: Mon, 31 Aug 1998 19:58:16 -0700 From: bmah@CA.Sandia.GOV (Bruce A. Mah) To: Don Lewis <Don.Lewis@tsc.tdk.com> Cc: bmah@california.sandia.gov, BUGTRAQ@netspace.org, security@FreeBSD.ORG Subject: Re: FreeBSD's RST validation Message-ID: <199809010258.TAA26568@stennis.ca.sandia.gov> In-Reply-To: Your message of "Mon, 31 Aug 1998 14:56:55 PDT." <199808312156.OAA28434@salsa.gv.tsc.tdk.com>
next in thread | previous in thread | raw e-mail | index | archive | help
If memory serves me right, Don Lewis wrote:
> Now that I look at this change some more, I think your added tests are
> a NOP because of the code just above this:
>
> if ((tiflags & TH_ACK) &&
> (SEQ_LEQ(ti->ti_ack, tp->iss) ||
> SEQ_GT(ti->ti_ack, tp->snd_max))) {
> [ snip comment ]
> if (taop->tao_ccsent != 0)
> goto drop;
> else
> goto dropwithreset;
>
> If the ACK is outside the window, the packet will already have been
> dropped before we even look for the RST flag.
Ah, yes. You're absolutely right. So it appears only the second of the
original patches is useful (if it's correct, that is).
This was a good day for me...I learned something.
Thanks!
Bruce.
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-security" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199809010258.TAA26568>