From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: [PATCH] Fix Malicious Guest GDT Host Crash Date: Thu, 09 Aug 2007 15:13:50 +1000 Message-ID: <1186636430.17752.35.camel@localhost.localdomain> References: <1186546220.17470.23.camel@localhost.localdomain> <13426df10708082140r61dbaf0m7f03da23e8bf0421@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <13426df10708082140r61dbaf0m7f03da23e8bf0421@mail.gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: ron minnich Cc: lguest , virtualization List-Id: virtualization@lists.linuxfoundation.org On Wed, 2007-08-08 at 21:40 -0700, ron minnich wrote: > On 8/7/07, Rusty Russell wrote: > > Hi all, > > > > Testing would be appreciated (esp. Ron?): I'd like to push this as soon > > as possible into 2.6.23. I thought of it while pondering kvm-lite, and > > then proved it was a problem... > > Works fine here. > > Be aware that in the early Plan 9 port to lguest I created a gdt entry > and forgot to wrap the GDT # with a macro with the result that I > loaded a gdt # instead of a selector into the gdt entry, and when the > guest switched back to the host (and back to guest, I guess) it > crashed my machine so hard that it went into the BIOS 'let's set this > brand new thinkpad up' dialog. Wow. That's impressive. It's understandable, however: I got a host triplefault here when a malformed GDT entry caused a #GP on guest entry. I'd be interested to check that this fixes it, but I'm pretty confident (it fixed it here). > The guys at the Plan 9 BOF at Google thought lguest was pretty darn cool. Cool! Rusty.