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.
Affected versions
Linux kernel versions
5.18
and later are affected. Fixed in
6.1.45,
6.4.10,
6.5
and their respective stable series.
References
The following references provide additional information about CVE-2023-54172 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/73626b70b361ddda7c380e52c236aa4f2487c402
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PatchKernel patch commithttps://git.kernel.org/stable/c/98cccbd0a19a161971bc7f7feb10577adc62c400
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PatchKernel patch commithttps://git.kernel.org/stable/c/d5ace2a776442d80674eff9ed42e737f7dd95056
Frequently asked questions
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What is CVE-2023-54172?
CVE-2023-54172 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.18 onward and has been patched in 6.1.45, 6.4.10 and 6.5. CVE-2023-54172 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2023-54172?
Yes — CVE-2023-54172 has been patched. Fixed versions include 6.1.45, 6.4.10 and 6.5. If you are running Linux kernel 5.18 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2023-54172 actively exploited?
No — CVE-2023-54172 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.