CVE-2023-54172 Details
Description
In the Linux kernel, the following vulnerability has been resolved: x86/hyperv: Disable IBT when hypercall page lacks ENDBR instruction On hardware that supports Indirect Branch Tracking (IBT), Hyper-V VMs with ConfigVersion 9.3 or later support IBT in the guest. However, current versions of Hyper-V have a bug in that there's not an ENDBR64 instruction at the beginning of the hypercall page. Since hypercalls are made with an indirect call to the hypercall page, all hypercall attempts fail with an exception and Linux panics. A Hyper-V fix is in progress to add ENDBR64. But guard against the Linux panic by clearing X86_FEATURE_IBT if the hypercall page doesn't start with ENDBR. The VM will boot and run without IBT. If future Linux 32-bit kernels were to support IBT, additional hypercall page hackery would be needed to make IBT work for such kernels in a Hyper-V VM.
A vulnerability in the Linux kernel's handling of Indirect Branch Tracking (IBT) has been identified in Hyper-V virtual machines running with ConfigVersion 9.3 or later. The issue arises because current Hyper-V versions do not include the required ENDBR64 instruction at the beginning of the hypercall page. This omission causes hypercall attempts to fail, leading to a Linux kernel panic. Although a fix is being developed to add the missing ENDBR64 instruction, the Linux kernel can be modified to disable IBT when the hypercall page is not properly configured. This vulnerability affects the Linux kernel in Hyper-V environments where IBT is supported but not functioning correctly due to the missing instruction.
The vulnerability has been addressed in the Linux kernel. Users can upgrade to the latest version of the stable Linux kernel to apply the fix.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Dec 30, 2025References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/73626b70b361ddda7c380e52c236aa4f2487c402 | kernel.org | Source CodeVendor |
| https://git.kernel.org/stable/c/98cccbd0a19a161971bc7f7feb10577adc62c400 | kernel.org | Source CodeVendor |
| https://git.kernel.org/stable/c/d5ace2a776442d80674eff9ed42e737f7dd95056 | kernel.org | Source CodeVendor |
Weakness Enumeration
No weakness enumeration is available for this CVE.
Affected Products
| Product | Versions |
|---|---|
| Linux kernel | All versions |
CPE
Remediation
| |
| Microsoft Hyper-V | All versions |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | kernel.org |
| Dec 30, 2025 | New CVE Received | kernel.org |