linux-kernel - Re: [PATCH RFC] virtio_pci: fix virtio spec compliance on restore

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20140924115913.GA32179@redhat.com>
Date:	Wed, 24 Sep 2014 14:59:13 +0300
From:	"Michael S. Tsirkin" <mst@...hat.com>
To:	Ben Hutchings <ben@...adent.org.uk>
Cc:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	Amit Shah <amit.shah@...hat.com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	virtualization@...ts.linux-foundation.org
Subject: Re: [PATCH RFC] virtio_pci: fix virtio spec compliance on restore

On Wed, Sep 24, 2014 at 02:27:27AM +0100, Ben Hutchings wrote:
> On Tue, 2014-09-23 at 13:32 +0300, Michael S. Tsirkin wrote:
> > On restore, virtio pci does the following:
> > + set features
> > + init vqs etc - device can be used at this point!
> > + set ACKNOWLEDGE,DRIVER and DRIVER_OK status bits
> > 
> > This is in violation of the virtio spec, which
> > requires the following order:
> > - ACKNOWLEDGE
> > - DRIVER
> > - init vqs
> > - DRIVER_OK
> >
> > Cc: stable@...r.kernel.org
> > Cc: Amit Shah <amit.shah@...hat.com>
> > Signed-off-by: Michael S. Tsirkin <mst@...hat.com>
> [...]
> 
> What concrete problem does this fix, such that it should be applied to
> stable branches?
> 
> Ben.

It will break with hypervisors that assume spec compliant behaviour.
I would like this applied to stable branches so hypervisors don't
need to support broken behaviour forever.

-- 
MST
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/