CVE-2022-26362

2022-06-0912:50:19

XEN

www.cve.org

xen

race condition

type reference count

tlb flush

guest

writeability

AI Score

Confidence

High

EPSS

Percentile

14.2%

JSON

x86 pv: Race condition in typeref acquisition Xen maintains a type reference count for pages, in addition to a regular reference count. This scheme is used to maintain invariants required for Xen’s safety, e.g. PV guests may not have direct writeable access to pagetables; updates need auditing by Xen. Unfortunately, the logic for acquiring a type reference has a race condition, whereby a safely TLB flush is issued too early and creates a window where the guest can re-establish the read/write mapping before writeability is prohibited.

CNA Affected

[
  {
    "product": "xen",
    "vendor": "Xen",
    "versions": [
      {
        "status": "unknown",
        "version": "consult Xen advisory XSA-401"
      }
    ]
  }
]