Comment 37 for bug 1647389

Definitely​ im waiting anxiously about this to be resolved also!

On Mar 31, 2017 20:35, "Marc Deslauriers" <email address hidden>
wrote:

I had a feeling perhaps CVE-2016-5403-3.patch needed to be backed out,
that's the commit I mentioned in comment #13.

Anxiously awaiting results of the test... :)

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Title:
  Regression: Live migrations can still crash after CVE-2016-5403 fix

Status in qemu package in Ubuntu:
  Confirmed
Status in qemu source package in Xenial:
  Confirmed

Bug description:
  [Impact]

   * Libvirt migrations using tunnelled libvirt cause a failure to
  migrate on the destination with error VQ 2 size 0x80 < last_avail_idx
  0x9 - used_idx 0xa

   * TBD: justification for backporting the fix to the stable release.
   * TBD: In addition, it is helpful, but not required, to include an
     explanation of how the upload fixes this bug.

  [Test Case]
  1. Create a VM on shared storage solution. In my case NFS.
  2. set start_libvirtd="yes" in /etc/default/libvirt-bin
  3. systemctl restart libvirt-bin
  4. virsh dommemstat 1 <vm>
  4. virsh -c qemu+ssh://${FROM}/system migrate --live --p2p --tunnelled
${VM} qemu+tcp://ubuntu@${TO}/system
  5. Repeat until failure to migrate, then check
/var/log/libvirt/qemu/<vm>.log for error from above.

  * Yes --live, --p2p, and --tunnelled are all required to reproduce
  afaik.

  [Regression Potential]
  TBD
   * discussion of how regressions are most likely to manifest as a result
of this change.
   * It is assumed that any SRU candidate patch is well-tested before
     upload and has a low overall risk of regression, but it's important
     to make the effort to think about what ''could'' happen in the
     event of a regression.
   * This both shows the SRU team that the risks have been considered,
     and provides guidance to testers in regression-testing the SRU.

  [Other Info]
  TBD
   * Anything else you think is useful to include
   * Anticipate questions from users, SRU, +1 maintenance, security teams
and the Technical Board
   * and address these questions in advance

  ___________________ Original Description follows _____________________

  See updates at the end of #1612089. Sample error message:

  Dec 05 14:41:07 zbk130713 libvirtd[29690]: internal error: early end of
file from monitor, possible problem:
  2016-12-05T14:41:07.903932Z qemu-system-x86_64: VQ 2 size 0x80 <
last_avail_idx 0x9 - used_idx 0xa
  2016-12-05T14:41:07.903981Z qemu-system-x86_64: error while loading state
for instance 0x0 of device '0000:00:05.0/virtio-balloon'
  2016-12-05T14:41:07.905180Z qemu-system-x86_64: load of migration failed:
Operation not permitted

  Seems related to this patch series:
  https://lists.gnu.org/archive/html/qemu-devel/2016-08/msg03079.html

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