CVE-2023-54172

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.

CVSS

No CVSS.

References

Link	Resource
https://git.kernel.org/stable/c/73626b70b361ddda7c380e52c236aa4f2487c402
https://git.kernel.org/stable/c/98cccbd0a19a161971bc7f7feb10577adc62c400
https://git.kernel.org/stable/c/d5ace2a776442d80674eff9ed42e737f7dd95056

Configurations

No configuration.

History

No history.

Information

Published : 2025-12-30 13:16

Updated : 2026-06-17 06:46

NVD link : CVE-2023-54172

Mitre link : CVE-2023-54172

CVE.ORG link : CVE-2023-54172

JSON object : View

Products Affected

No product.

CWE

No CWE.

{"id": "CVE-2023-54172", "cveTags": [], "metrics": {}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "991625f3dd2cbc4b787deb0213e2bcf8fa264b21", "lessThan": "98cccbd0a19a161971bc7f7feb10577adc62c400", "versionType": "git"}, {"status": "affected", "version": "991625f3dd2cbc4b787deb0213e2bcf8fa264b21", "lessThan": "73626b70b361ddda7c380e52c236aa4f2487c402", "versionType": "git"}, {"status": "affected", "version": "991625f3dd2cbc4b787deb0213e2bcf8fa264b21", "lessThan": "d5ace2a776442d80674eff9ed42e737f7dd95056", "versionType": "git"}], "programFiles": ["arch/x86/hyperv/hv_init.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.18"}, {"status": "unaffected", "version": "0", "lessThan": "5.18", "versionType": "semver"}, {"status": "unaffected", "version": "6.1.45", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.4.10", "versionType": "semver", "lessThanOrEqual": "6.4.*"}, {"status": "unaffected", "version": "6.5", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["arch/x86/hyperv/hv_init.c"], "defaultStatus": "affected"}]}], "published": "2025-12-30T13:16:05.050", "references": [{"url": "https://git.kernel.org/stable/c/73626b70b361ddda7c380e52c236aa4f2487c402", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/98cccbd0a19a161971bc7f7feb10577adc62c400", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d5ace2a776442d80674eff9ed42e737f7dd95056", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Deferred", "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/hyperv: Disable IBT when hypercall page lacks ENDBR instruction\n\nOn hardware that supports Indirect Branch Tracking (IBT), Hyper-V VMs\nwith ConfigVersion 9.3 or later support IBT in the guest. However,\ncurrent versions of Hyper-V have a bug in that there's not an ENDBR64\ninstruction at the beginning of the hypercall page. Since hypercalls are\nmade with an indirect call to the hypercall page, all hypercall attempts\nfail with an exception and Linux panics.\n\nA Hyper-V fix is in progress to add ENDBR64. But guard against the Linux\npanic by clearing X86_FEATURE_IBT if the hypercall page doesn't start\nwith ENDBR. The VM will boot and run without IBT.\n\nIf future Linux 32-bit kernels were to support IBT, additional hypercall\npage hackery would be needed to make IBT work for such kernels in a\nHyper-V VM."}], "lastModified": "2026-06-17T06:46:56.200", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}