CVE-2023-46837 Information

Description

Arm provides multiple helpers to clean & invalidate the cache for a given region. This is for instance used when allocating guest memory to ensure any writes (such as the ones during scrubbing) have reached memory before handing over the page to a guest.

Unfortunately the arithmetics in the helpers can overflow and would then result to skip the cache cleaning/invalidation. Therefore there is no guarantee when all the writes will reach the memory.

This undefined behavior was meant to be addressed by XSA-437 but the approach was not sufficient.

Reference

https://xenbits.xenproject.org/xsa/advisory-447.html