A QEMU regression update has been released for Ubuntu Linux 16.04 LTS, 18.04 LTS, 20.04 LTS, and 20.10.

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Ubuntu Security Notice USN-4467-3
February 22, 2021

qemu regression
==========================================================================

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

- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

USN-4467-1 introduced a regression in QEMU.

Software Description:
- qemu: Machine emulator and virtualizer

Details:

USN-4467-1 fixed vulnerabilities in QEMU. The fix for CVE-2020-13754
introduced a regression in certain environments. This update fixes the
problem.

We apologize for the inconvenience.

Original advisory details:

Ren Ding, Hanqing Zhao, Alexander Bulekov, and Anatoly Trosinenko
discovered that the QEMU incorrectly handled certain msi-x mmio operations.
An attacker inside a guest could possibly use this issue to cause QEMU to
crash, resulting in a denial of service. (CVE-2020-13754)

Update instructions:

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

Ubuntu 20.10:
qemu 1:5.0-5ubuntu9.6
qemu-system 1:5.0-5ubuntu9.6
qemu-system-arm 1:5.0-5ubuntu9.6
qemu-system-mips 1:5.0-5ubuntu9.6
qemu-system-misc 1:5.0-5ubuntu9.6
qemu-system-ppc 1:5.0-5ubuntu9.6
qemu-system-s390x 1:5.0-5ubuntu9.6
qemu-system-sparc 1:5.0-5ubuntu9.6
qemu-system-x86 1:5.0-5ubuntu9.6
qemu-system-x86-microvm 1:5.0-5ubuntu9.6
qemu-system-x86-xen 1:5.0-5ubuntu9.6

Ubuntu 20.04 LTS:
qemu 1:4.2-3ubuntu6.14
qemu-system 1:4.2-3ubuntu6.14
qemu-system-arm 1:4.2-3ubuntu6.14
qemu-system-mips 1:4.2-3ubuntu6.14
qemu-system-misc 1:4.2-3ubuntu6.14
qemu-system-ppc 1:4.2-3ubuntu6.14
qemu-system-s390x 1:4.2-3ubuntu6.14
qemu-system-sparc 1:4.2-3ubuntu6.14
qemu-system-x86 1:4.2-3ubuntu6.14
qemu-system-x86-microvm 1:4.2-3ubuntu6.14
qemu-system-x86-xen 1:4.2-3ubuntu6.14

Ubuntu 18.04 LTS:
qemu 1:2.11+dfsg-1ubuntu7.36
qemu-system 1:2.11+dfsg-1ubuntu7.36
qemu-system-arm 1:2.11+dfsg-1ubuntu7.36
qemu-system-mips 1:2.11+dfsg-1ubuntu7.36
qemu-system-misc 1:2.11+dfsg-1ubuntu7.36
qemu-system-ppc 1:2.11+dfsg-1ubuntu7.36
qemu-system-s390x 1:2.11+dfsg-1ubuntu7.36
qemu-system-sparc 1:2.11+dfsg-1ubuntu7.36
qemu-system-x86 1:2.11+dfsg-1ubuntu7.36

Ubuntu 16.04 LTS:
qemu 1:2.5+dfsg-5ubuntu10.51
qemu-system 1:2.5+dfsg-5ubuntu10.51
qemu-system-aarch64 1:2.5+dfsg-5ubuntu10.51
qemu-system-arm 1:2.5+dfsg-5ubuntu10.51
qemu-system-mips 1:2.5+dfsg-5ubuntu10.51
qemu-system-misc 1:2.5+dfsg-5ubuntu10.51
qemu-system-ppc 1:2.5+dfsg-5ubuntu10.51
qemu-system-s390x 1:2.5+dfsg-5ubuntu10.51
qemu-system-sparc 1:2.5+dfsg-5ubuntu10.51
qemu-system-x86 1:2.5+dfsg-5ubuntu10.51

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

References:
  https://usn.ubuntu.com/4467-3
  https://usn.ubuntu.com/4467-1
  https://launchpad.net/bugs/1914883

Package Information:
  https://launchpad.net/ubuntu/+source/qemu/1:5.0-5ubuntu9.6
  https://launchpad.net/ubuntu/+source/qemu/1:4.2-3ubuntu6.14
  https://launchpad.net/ubuntu/+source/qemu/1:2.11+dfsg-1ubuntu7.36
  https://launchpad.net/ubuntu/+source/qemu/1:2.5+dfsg-5ubuntu10.51