| Name | CVE-2023-46842 |
| Description | Unlike 32-bit PV guests, HVM guests may switch freely between 64-bit and
other modes. This in particular means that they may set registers used
to pass 32-bit-mode hypercall arguments to values outside of the range
32-bit code would be able to set them to.
When processing of hypercalls takes a considerable amount of time,
the hypervisor may choose to invoke a hypercall continuation. Doing so
involves putting (perhaps updated) hypercall arguments in respective
registers. For guests not running in 64-bit mode this further involves
a certain amount of translation of the values.
Unfortunately internal sanity checking of these translated values
assumes high halves of registers to always be clear when invoking a
hypercall. When this is found not to be the case, it triggers a
consistency check in the hypervisor and causes a crash.
|
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| xen (PTS) | jessie, jessie (lts) | 4.4.4lts5-0+deb8u1 | vulnerable |
| stretch (security), stretch (lts), stretch | 4.8.5.final+shim4.10.4-1+deb9u12 | vulnerable |
| buster (security), buster, buster (lts) | 4.11.4+107-gef32c7afa2-1 | fixed |
| bullseye | 4.14.6-1 | vulnerable |
| bullseye (security) | 4.14.5+94-ge49571868d-1 | vulnerable |
| bookworm | 4.17.3+10-g091466ba55-1~deb12u1 | vulnerable |
| sid, trixie | 4.17.3+36-g54dacb5c02-1 | vulnerable |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| xen | source | jessie | (unfixed) | end-of-life | | |
| xen | source | stretch | (unfixed) | end-of-life | | |
| xen | source | buster | (not affected) | | | |
| xen | source | bullseye | (unfixed) | end-of-life | | |
| xen | source | (unstable) | (unfixed) | | | |
Notes
[bookworm] - xen <postponed> (Minor issue, fix along in next DSA)
[bullseye] - xen <end-of-life> (EOLed in Bullseye)
[buster] - xen <not-affected> (Vulnerable code not present)
https://xenbits.xen.org/xsa/advisory-454.html