----- Original Message ----- From: "Devon H. O'Dell" <[EMAIL PROTECTED]> To: "Matt Emmerton" <[EMAIL PROTECTED]>; "Mike Meyer" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Saturday, September 18, 2004 4:01 AM Subject: Re: FreeBSD Kernel buffer overflow
> --------- Original Message -------- > From: Matt Emmerton <[EMAIL PROTECTED]> > To: Mike Meyer <[EMAIL PROTECTED]> > Cc: [EMAIL PROTECTED], [EMAIL PROTECTED], > [EMAIL PROTECTED] > Subject: Re: FreeBSD Kernel buffer overflow > Date: 18/09/04 05:41 > > > > > > > ----- Original Message ----- > > From: "Mike Meyer" <[EMAIL PROTECTED]> > > To: "Matt Emmerton" <[EMAIL PROTECTED]> > > Cc: <[EMAIL PROTECTED]>; "Avleen Vig" > > <[EMAIL PROTECTED]>; > <[EMAIL PROTECTED]>; > > <[EMAIL PROTECTED]> > > Sent: Saturday, September 18, 2004 1:22 AM > > Subject: Re: FreeBSD Kernel buffer overflow > > > > > > > In <[EMAIL PROTECTED]>, Matt > Emmerton > > <[EMAIL PROTECTED]> typed: > > > > I disagree. It really comes down to how secure you want FreeBSD > to be, > > and > > > > the attitude of "we don't need to protect against this case > because > > anyone > > > > who does this is asking for trouble anyway" is one of the > main reason > > why > > > > security holes exist in products today. (Someone else had > brought this > > up > > > > much earlier on in the thread.) > > > > > > You haven't been paying close enough attention to the discussion. To > > > exploit this "security problem" you have to be root. If > it's an > > > external attacker, you're already owned. > > > > I'm well aware of that fact. That's still not a reason to protect against > > the problem. > > > > If your leaky bucket has 10 holes in it, would you at least try and plug > > some of them? > > > > -- > > Matt Emmerton > > So should we stop the command ``shutdown -h now'' from working for root? > After all, he can DoS the system with it? > > How about this: let's disallow root from loading kernel modules! That way > this can't ever happen. > > Even better: Why don't we just not boot into a usable environment! Then we > have NO security holes. > > You guys are failing to see: ROOT HAS OMNIPOTENT POWER. SOMEBODY MUST HAVE > OMNIPOTENT POWER. THIS IS NOT A BUG. THERE IS NOTHING TO SEE HERE, MOVE ON. > > Not to be sarcastic, but you guys are missing the problem. The problem was > that someone was unaware of a kernel API. When you start programming for the > kernel, you need to make sure that the code is secure. If you think this is > a problem, take a look at init(8) and learn about securelevels. > > What happened: someone was unfamiliar with the syscall API. They crashed > their system. They screamed wildly, believing they'd found a buffer > overflow, when they'd merely overloaded the function stack and screwed up > the call. This caused the system to reboot. Solution: make it more clear > that syscalls take only 8 arguments. Make it clear that you can pass > arguments in a struct to a syscall. Make it clear that many/most syscalls do > this anyway. If there's beef on this, take it to [EMAIL PROTECTED] Mike and I discussed this offline. Can someone just step up to work on and commit the KASSERT code which handles the problem and end the thread? The only reason I piped up was because nothing had been done yet, and suggested two alternate ways of hardening the system that could be enabled/disabled by the system administrator, instead of being always enabled (like a KASSERT, which always incurs a run-time check and thus could hurt performance.) -- Matt Emmerton _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
