CVE-2020-11739

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

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 have a writer executing a critical section at the same time as readers or another writer. • http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00006.html http://www.openwall.com/lists/oss-security/2020/04/14/2 http://xenbits.xen.org/xsa/advisory-314.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5M2XRNCHOGGTJQBZQJ7DCV6ZNAKN3LE2 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVTP4OYHCTRU3ONFJOFJQVNDFB25KLLG https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YMAW7D2MP • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') •