race in VT-d domain ID cleanup Xen domain IDs are up to 15 bits wide. VT-d hardware may allow for only less than 15 bits to hold a domain ID associating a physical device with a particular domain. Therefore internally Xen domain IDs are mapped to the smaller value range. The cleaning up of the housekeeping structures has a race, allowing for VT-d domain IDs to be leaked and flushes to be bypassed.
https://xenbits.xenproject.org/xsa/advisory-399.txt
https://www.debian.org/security/2022/dsa-5117
https://security.gentoo.org/glsa/202402-07