qemu regression

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)