Re: [Qemu-stable] Patch Round-up for stable 2.2.1, freeze on 2015-03-05

[Peter Lieven]

Am 09.03.2015 um 04:56 schrieb Michael Roth:
> Quoting Peter Lieven (2015-03-08 13:02:04)
> > Am 25.02.2015 um 14:25 schrieb Peter Lieven:
> > > Am 24.02.2015 um 22:47 schrieb Michael Roth:
> > > > Hi everyone,
> > > >
> > > > The following new patches are queued for QEMU stable v2.2.1:
> > > >
> > > >    https://github.com/mdroth/qemu/commits/stable-2.2-staging
> > > >
> > > > The release is planned for 2015-03-10:
> > > >
> > > >    http://wiki.qemu.org/Planning/2.2
> > > >
> > > > Please respond here or CC address@hidden on any patches you
> > > > think should be included in the release.
> > > Please include from Kevins block repo:
> > >
> > > commit fca313a4f02bf166864636b1f47995c9fbf2716f
> > > Author: Kevin Wolf <address@hidden>
> > > Date:   Wed Feb 11 17:19:57 2015 +0100
> > >
> > >      vpc: Fix size in fixed image creation
> > >
> > > commit 12d596c9b29608ede4df3844038c799014d0661f
> > > Author: Kevin Wolf <address@hidden>
> > > Date:   Tue Feb 10 11:17:53 2015 +0100
> > >
> > >      coroutine: Fix use after free with qemu_coroutine_yield()
> > >
> > > Peter
> > Hi Michael,
> >
> > have you got these two? At least the last one is quite important.
> I've gone ahead and pulled them in from Stefan's block tree. It's a bit
> late in the test cycle so if you happen to have a workload that
> exercises these paths your testing would be appreciated. I've pushed
> the latest here:
>
>    https://github.com/mdroth/qemu/commits/stable-2.2-staging

The patch was sitting in Kevins Repo for quite some time. I have asked
Kevin off-list if there are any concerns merging this patch.
Stefan has added a test to test-coroutine to trigger the use-after-free:

http://repo.or.cz/w/qemu/kevin.git/commit/a2439f8e7e23e03f64a9388e31450084072ba0f2

Kevin told me that the bug was reported in conjunction with NBD. But I think
it can occur at several places in the block layer as well. As it is a 
use-after-free
it might work as well as trigger all kinds of behaviour.

I personally have this patch in my qemu 2.2 build for some weeks and
have it running on several hundreds our vServers. Without
any issues so far.

Peter