CVE-2023-54172

kernel: x86/hyperv: Disable IBT when hypercall page lacks ENDBR instruction

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Severity

Low

Red Hat Product Security

3.3

CVSS 3.1

Review impact separately from score.

Published · December 30, 2025

Updated · June 30, 2026

Description

A compatibility issue was found between Linux and Hyper-V when Indirect Branch Tracking (IBT) is enabled. The Hyper-V hypercall page lacks the required ENDBR64 instruction, causing all hypercalls to fail with an exception and panic the guest.

Statement

This affects only Hyper-V guests with IBT-capable hardware and specific VM configuration versions. The kernel fix works around the Hyper-V bug by disabling IBT when the hypercall page is incompatible, allowing the VM to boot without IBT protection.

CVSS score applicability

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation

No mitigation is specified in collected source.

CVSS / CWE

CVSS 3.1 · 3.3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

CWE-166 · Improper Handling of Missing Special Element