==========================================================================
Ubuntu Security Notice USN-3047-2
August 12, 2016

qemu, qemu-kvm regression
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS
- Ubuntu 12.04 LTS

Summary:

USN-3047-1 introduced a regression in QEMU.

Software Description:
- qemu: Machine emulator and virtualizer
- qemu-kvm: Machine emulator and virtualizer

Details:

USN-3047-1 fixed vulnerabilities in QEMU. The patch to fix CVE-2016-5403
caused a regression which resulted in save/restore failures when virtio
memory balloon statistics are enabled. This update temporarily reverts the
security fix for CVE-2016-5403 pending further investigation. We apologize
for the inconvenience.

Original advisory details:

 Li Qiang discovered that QEMU incorrectly handled 53C9X Fast SCSI
 controller emulation. A privileged attacker inside the guest could use this
 issue to cause QEMU to crash, resulting in a denial of service, or possibly
 execute arbitrary code on the host. In the default installation, when QEMU
 is used with libvirt, attackers would be isolated by the libvirt AppArmor
 profile. This issue only applied to Ubuntu 14.04 LTS and Ubuntu 16.04 LTS.
 (CVE-2016-4439, CVE-2016-4441, CVE-2016-5238, CVE-2016-5338, CVE-2016-6351)
  Li Qiang and Qinghao Tang discovered that QEMU incorrectly handled the
 VMWare VGA module. A privileged attacker inside the guest could use this
 issue to cause QEMU to crash, resulting in a denial of service, or possibly
 to obtain sensitive host memory. (CVE-2016-4453, CVE-2016-4454)
  Li Qiang discovered that QEMU incorrectly handled VMWARE PVSCSI paravirtual
 SCSI bus emulation support. A privileged attacker inside the guest could
 use this issue to cause QEMU to crash, resulting in a denial of service.
 This issue only applied to Ubuntu 14.04 LTS and Ubuntu 16.04 LTS.
 (CVE-2016-4952)
  Li Qiang discovered that QEMU incorrectly handled MegaRAID SAS 8708EM2 Host
 Bus Adapter emulation support. A privileged attacker inside the guest could
 use this issue to cause QEMU to crash, resulting in a denial of service, or
 possibly to obtain sensitive host memory. This issue only applied to Ubuntu
 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2016-5105, CVE-2016-5106,
 CVE-2016-5107, CVE-2016-5337)
  It was discovered that QEMU incorrectly handled certain iSCSI asynchronous
 I/O ioctl calls. An attacker inside the guest could use this issue to cause
 QEMU to crash, resulting in a denial of service, or possibly execute
 arbitrary code on the host. In the default installation, when QEMU is used
 with libvirt, attackers would be isolated by the libvirt AppArmor profile.
 This issue only applied to Ubuntu 14.04 LTS and Ubuntu 16.04 LTS.
 (CVE-2016-5126)
  Zhenhao Hong discovered that QEMU incorrectly handled the Virtio module. A
 privileged attacker inside the guest could use this issue to cause QEMU to
 crash, resulting in a denial of service. (CVE-2016-5403)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 16.04 LTS:
  qemu-system                     1:2.5+dfsg-5ubuntu10.4
  qemu-system-aarch64             1:2.5+dfsg-5ubuntu10.4
  qemu-system-arm                 1:2.5+dfsg-5ubuntu10.4
  qemu-system-mips                1:2.5+dfsg-5ubuntu10.4
  qemu-system-misc                1:2.5+dfsg-5ubuntu10.4
  qemu-system-ppc                 1:2.5+dfsg-5ubuntu10.4
  qemu-system-s390x               1:2.5+dfsg-5ubuntu10.4
  qemu-system-sparc               1:2.5+dfsg-5ubuntu10.4
  qemu-system-x86                 1:2.5+dfsg-5ubuntu10.4

Ubuntu 14.04 LTS:
  qemu-system                     2.0.0+dfsg-2ubuntu1.27
  qemu-system-aarch64             2.0.0+dfsg-2ubuntu1.27
  qemu-system-arm                 2.0.0+dfsg-2ubuntu1.27
  qemu-system-mips                2.0.0+dfsg-2ubuntu1.27
  qemu-system-misc                2.0.0+dfsg-2ubuntu1.27
  qemu-system-ppc                 2.0.0+dfsg-2ubuntu1.27
  qemu-system-sparc               2.0.0+dfsg-2ubuntu1.27
  qemu-system-x86                 2.0.0+dfsg-2ubuntu1.27

Ubuntu 12.04 LTS:
  qemu-kvm                        1.0+noroms-0ubuntu14.30

After a standard system update you need to restart all QEMU virtual
machines to make all the necessary changes.

References:
  http://www.ubuntu.com/usn/usn-3047-2
  http://www.ubuntu.com/usn/usn-3047-1
  https://launchpad.net/bugs/1612089

Package Information:
  https://launchpad.net/ubuntu/+source/qemu/1:2.5+dfsg-5ubuntu10.4
  https://launchpad.net/ubuntu/+source/qemu/2.0.0+dfsg-2ubuntu1.27
  https://launchpad.net/ubuntu/+source/qemu-kvm/1.0+noroms-0ubuntu14.30