insufficient TLB flush for x86 PV guests in shadow mode For migration as well as to work around kernels unaware of L1TF (see XSA-273), PV guests may be run in shadow paging mode. To address XSA-401, code was moved inside a function in Xen. This code movement missed a variable changing meaning / value between old and new code positions. The now wrong use of the variable did lead to a wrong TLB flush condition, omitting flushes where such are necessary.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Xen | Xen | * | * |
| Xen | Ubuntu | bionic | * |
| Xen | Ubuntu | focal | * |
| Xen | Ubuntu | kinetic | * |
| Xen | Ubuntu | lunar | * |
| Xen | Ubuntu | mantic | * |
| Xen | Ubuntu | oracular | * |
| Xen | Ubuntu | plucky | * |
| Xen | Ubuntu | trusty | * |
| Xen | Ubuntu | xenial | * |
References
- http://www.openwall.com/lists/oss-security/2022/07/26/2
- http://www.openwall.com/lists/oss-security/2022/07/26/3
- http://xenbits.xen.org/xsa/advisory-408.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HUFIMNGYP5VQAA6KE3T2I5GW6UP6F7BS/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MYI3OMJ7RIZNL3C6GUWNANNPEUUID6FM/
- https://www.debian.org/security/2022/dsa-5272
- https://xenbits.xenproject.org/xsa/advisory-408.txt
- http://www.openwall.com/lists/oss-security/2022/07/26/2
- http://www.openwall.com/lists/oss-security/2022/07/26/3
- http://xenbits.xen.org/xsa/advisory-408.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HUFIMNGYP5VQAA6KE3T2I5GW6UP6F7BS/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MYI3OMJ7RIZNL3C6GUWNANNPEUUID6FM/
- https://www.debian.org/security/2022/dsa-5272
- https://xenbits.xenproject.org/xsa/advisory-408.txt