[PATCH 4/7] hvc_console: Fix race between hvc_close and hvc_remove

[Alan Cox]

On Sun, 21 Mar 2010 08:04:39 +1100
Benjamin Herrenschmidt <benh at kernel.crashing.org> wrote:

> On Fri, 2010-03-19 at 08:18 -0700, Greg Kroah-Hartman wrote:
> > From: Amit Shah <amit.shah at redhat.com>
> > 
> > Alan pointed out a race in the code where hvc_remove is invoked. The
> > recent virtio_console work is the first user of hvc_remove().
> 
> This causes hangs during boot on pseries machines. Haven't had a chance
> to track that down yet, but please revert
> e74d098c66543d0731de62eb747ccd5b636a6f4c for now.

Its an exploitable hole so we should revert both the bug fix *and* the
submission of the virtio console that makes the flaw triggerable, not jus
tthe security fix.

Alan