CVE-2020-11739 – Ubuntu Security Notice USN-5617-1

https://notcve.org/view.php?id=CVE-2020-11739

14 Apr 2020 — An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service or possibly gain privileges because of missing memory barriers in read-write unlock paths. The read-write unlock paths don't contain a memory barrier. On Arm, this means a processor is allowed to re-order the memory access with the preceding ones. In other words, the unlock may be seen by another processor before all the memory accesses within the "critical" section. As a consequence, it may be possible to ha... • http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00006.html • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') •