CVE-2023-46842

2024-05-1614:15:08

[email protected]

web.nvd.nist.gov

764

hvm guests

64-bit mode

hypercall arguments

hypervisor crash

6.3 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

9.1%

JSON

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.

CNA Affected

[
  {
    "defaultStatus": "unknown",
    "product": "Xen",
    "vendor": "Xen",
    "versions": [
      {
        "status": "unknown",
        "version": "consult Xen advisory XSA-454"
      }
    ]
  }
]