Date: Sat, 25 Sep 1999 08:52:56 -0700 From: Cy Schubert - ITSD Open Systems Group <Cy.Schubert@uumail.gov.bc.ca> To: Fernando Schapachnik <fpscha@via-net-works.net.ar> Cc: freebsd-security@FreeBSD.ORG Subject: Re: FreeBSD-specific denial of service (fwd) Message-ID: <199909251553.IAA02103@passer.osg.gov.bc.ca> In-Reply-To: Your message of "Fri, 24 Sep 1999 12:14:46 -0300." <199909241514.MAA15064@ns1.sminter.com.ar>
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In message <199909241514.MAA15064@ns1.sminter.com.ar>, Fernando =
Schapachnik wri
tes:
> Anyone has a patch for this?
> =
> Regards.
> =
> ----- Forwarded message from Charles M. Hannum -----
> =
> >From owner-bugtraq@SECURITYFOCUS.COM Wed Sep 22 14:55:30 1999
> Approved-By: aleph1@SECURITYFOCUS.COM
> Delivered-To: bugtraq@lists.securityfocus.com
> Delivered-To: bugtraq@securityfocus.com
> Message-ID: <199909211950.PAA09009@bill-the-cat.mit.edu>
> Date: Tue, 21 Sep 1999 15:50:58 -0400
> Reply-To: "Charles M. Hannum" <root@IHACK.NET>
> Sender: Bugtraq List <BUGTRAQ@SECURITYFOCUS.COM>
> From: "Charles M. Hannum" <root@IHACK.NET>
> Subject: FreeBSD-specific denial of service
> X-To: bugtraq@securityfocus.com
> To: BUGTRAQ@SECURITYFOCUS.COM
> =
> [Resending once, since it's been 10.5 days...]
> =
> Here's an interesting denial-of-service attack against FreeBSD >=3D3.0
> systems. It abuses a flaw in the `new' FreeBSD vfs_cache.c; it has no
> way to purge entries unless the `vnode' (e.g. the file) they point to
> is removed from memory -- which generally doesn't happen unless a
> certain magic number of `vnodes' is in use, and never happens when the
> `vnode' (i.e. file) is open. Thus it's possible to chew up an
> arbitrary amount of wired kernel memory relatively simply.
[exploit code deleted -- see previous post]
This has been fixed in 3.3 and I've tested it. No crash even while =
running some other memory intensive work on the box.
Regards, Phone: (250)387-8437
Cy Schubert Fax: (250)387-5766
Open Systems Group Internet: Cy.Schubert@uumail.gov.bc.ca
ITSD Cy.Schubert@gems8.gov.bc.ca
Province of BC
"e**(i*pi)+1=3D0"
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