CVE-2022-42324

2022-11-0100:00:00

XEN

www.cve.org

oxenstored

integer truncation

logic confusion

unexpected exceptions

xenstore ring

7.1 High

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

14.3%

JSON

Oxenstored 32->31 bit integer truncation issues Integers in Ocaml are 63 or 31 bits of signed precision. The Ocaml Xenbus library takes a C uint32_t out of the ring and casts it directly to an Ocaml integer. In 64-bit Ocaml builds this is fine, but in 32-bit builds, it truncates off the most significant bit, and then creates unsigned/signed confusion in the remainder. This in turn can feed a negative value into logic not expecting a negative value, resulting in unexpected exceptions being thrown. The unexpected exception is not handled suitably, creating a busy-loop trying (and failing) to take the bad packet out of the xenstore ring.

CNA Affected

[
  {
    "vendor": "Xen",
    "product": "xen",
    "versions": [
      {
        "version": "consult Xen advisory XSA-420",
        "status": "unknown"
      }
    ]
  }
]