An issue was discovered in Xen 4.9 through 4.14.x. On Arm, a guest is allowed to control whether memory accesses are bypassing the cache. This means that Xen needs to ensure that all writes (such as the ones during scrubbing) have reached the memory before handing over the page to a guest. Unfortunately, the operation to clean the cache is happening before checking if the page was scrubbed. Therefore there is no guarantee when all the writes will reach the memory.
Advisories
Source ID Title
Debian DSA Debian DSA DSA-4888-1 xen security update
EUVD EUVD EUVD-2021-13715 An issue was discovered in Xen 4.9 through 4.14.x. On Arm, a guest is allowed to control whether memory accesses are bypassing the cache. This means that Xen needs to ensure that all writes (such as the ones during scrubbing) have reached the memory before handing over the page to a guest. Unfortunately, the operation to clean the cache is happening before checking if the page was scrubbed. Therefore there is no guarantee when all the writes will reach the memory.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2024-08-03T20:33:41.404Z

Reserved: 2021-02-09T00:00:00

Link: CVE-2021-26933

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2021-02-17T02:15:13.097

Modified: 2024-11-21T05:57:04.653

Link: CVE-2021-26933

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.