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Date:      Wed, 27 May 1998 10:39:28 -0700
From:      Mike Smith <mike@smith.net.au>
To:        "Brian Feldman" <brianfeldman@hotmail.com>
Cc:        freebsd-current@FreeBSD.ORG
Subject:   Re: current instabilities 
Message-ID:  <199805271739.KAA00888@dingo.cdrom.com>
In-Reply-To: Your message of "27 May 1998 03:23:29 -0000." <19980527032329.16263.qmail@m2.findmail.com> 

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> 2) "options	VM86" - EVIL EVIL EVIL! This really allows way too much
> access to the memory by a mortal

I'm curious as to what you mean by this.  What "memory" does it allow 
access to?

>, and it's an effective DoS attack if a
> user runs doscmd, say, and a certain executable (this time, I happened
> to try ZSnes). 

There may still be bugs in the vm86 handling, and we'd like to know if 
you find them.  What you were running sounds like a graphical program, 
and there is no support for graphics in doscmd.  You wouldn't happen to 
have run with the '-r' flag now would you?

> Think there may be a way to make this safer? (I locked
> myself up, and it didn't panic so I don't know what exact function
> caused it). Also, could USER_LDT possibly be used as a DoS attack, like
> it seems to me it could?

Again, it shouldn't, no.  What services do you plan to deny?

-- 
\\  Sometimes you're ahead,       \\  Mike Smith
\\  sometimes you're behind.      \\  mike@smith.net.au
\\  The race is long, and in the  \\  msmith@freebsd.org
\\  end it's only with yourself.  \\  msmith@cdrom.com



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