cbcvebase.
CVE-2023-54172
published 2025-12-30

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…

PriorityP420low3.3
EPSS
0.17%
6.9th percentile
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

10 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.52-1 (bookworm)linux 6.1.52-1 (bookworm)
linuxlinux
linuxlinux>= 991625f3dd2cbc4b787deb0213e2bcf8fa264b21 < 98cccbd0a19a161971bc7f7feb10577adc62c40098cccbd0a19a161971bc7f7feb10577adc62c400
linuxlinux>= 991625f3dd2cbc4b787deb0213e2bcf8fa264b21 < 73626b70b361ddda7c380e52c236aa4f2487c40273626b70b361ddda7c380e52c236aa4f2487c402
linuxlinux>= 991625f3dd2cbc4b787deb0213e2bcf8fa264b21 < d5ace2a776442d80674eff9ed42e737f7dd95056d5ace2a776442d80674eff9ed42e737f7dd95056
linuxlinux_kernel>= 0 < 6.1.52-16.1.52-1
linuxlinux_kernel>= 0 < 6.4.11-16.4.11-1
linuxlinux_kernel>= 0 < 6.4.11-16.4.11-1
linuxlinux_kernel>= 5.18.0 < 6.1.456.1.45
linuxlinux_kernel>= 6.2.0 < 6.4.106.4.10
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.