Re: Changes in kernel 5.18-rc1 leads to crashes in VirtualBox Virtual Machines

From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: Larry Finger <Larry.Finger@lwfinger.net>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: Re: Changes in kernel 5.18-rc1 leads to crashes in VirtualBox Virtual Machines
Date: Mon, 2 May 2022 03:05:01 +0200	[thread overview]
Message-ID: <Ym8uPcuQpq1xBS6d@zx2c4.com> (raw)
In-Reply-To: <Ym8hoW7J60xAQv8f@zx2c4.com>

Hi Larry,

On Mon, May 02, 2022 at 02:11:13AM +0200, Jason A. Donenfeld wrote:
> Hey again,
> 
> I just installed VirtualBox ontop of 5.18-rc4, and then I made a new VM
> with a fresh install of OpenSUSE, and everything is fine. No issues at
> all.
> 
> So you're going to have to provide more information.
> 
> Jason

With still no more information provided from you, I've gone scouring and
found your much more informative bug report here:
https://www.virtualbox.org/ticket/20914 along with a larger log here
https://www.virtualbox.org/attachment/ticket/20914/Windows%2010%20Clone-2022-04-24-20-55-56.log

Why would you not have sent me all this information right away? Surely
you know how to report bugs. If you're going to concern me with the
possibility that I've broken something, at least give me enough detail
to be able to do something. Otherwise it's pure frustration.

Anyway, it's still too little information, but I could extract the
Windows build from that log file, pull down ntoskrnl.exe and hope it
roughly matches, and then go to work in IDA Pro trying to figure out
what's going on at ntoskrnl.exe+3f7d50, and if I managed to grab the
right build -- which I more than likely did not -- then that's a `mov
byte ptr gs:853h, 0` in KiInterruptDispatch, which seems entirely
unrelated to the change you mentioned.

So I think it'd be a good moment for you to show your bisect logs so we
can be certain we're after the right thing.

Jason