Re: Local DoS in FreeBSD

From: Jeff Wheat (jeffat_private)
Date: Thu Sep 02 1999 - 13:51:33 PDT

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    On 01-Sep-99 Darren Reed wrote:
    >>
    >> This was first posted to the FreeBSD security list on the 9th of August,
    >> subsequently discussed on freebsd-stable and freebsd-hackers... no one
    >> seems to care, even though it is able to lock up 2.2.6, 2.2.8, and 3.2.x
    >> machines consistantly. I have also been told that it affects NetBSD and
    >> OpenBSD, though I haven't confirmed it.
    >>
    >> Someone with the know-how care to fix?
    >
    > Fixing this has been discussed internally, I imagine, by many of the
    > affected OS's.  The problem is a resource stavation issue - in this
    > case mbuf's.  Arguably, it shouldn't "lock up", just freeze up anything
    > that does networking.
    >
    > I imagine you could lock up more than just the *BSD's with this program.
    >
    > Darren
    
    In all the tests that I have conducted on my FreeBSD systems, both
    intel and alpha based, versions 2.2.2 through 4.0-19990809-CURRENT
    result in the machines rebooting after running this DoS. The only
    work-around for this is supposedly setting resource limits in the
    /etc/login.conf file or to prevent public access to the machines.
    
    Regards,
    Jeff
    



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