CVE-2024-53135

CVE-2024-53135 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Bury Intel PT virtualization (guest/host mode) behind CONFIG_BROKEN Hide KVM's pt_mode module param behind CONFIG_BROKEN, i.e. disable support for virtualizing Intel PT via guest/host mode unless BROKEN=y. There are myriad bugs in the implementation, some of which are fatal to the guest, and others which put the stability and health of the host at risk. For guest fatalities, the most glaring issue is that KVM fails to ensure tracing is disabled, and *stays* disabled prior to VM-Enter, which is necessary as hardware disallows loading (the guest's) RTIT_CTL if tracing is enabled (enforced via a VMX consistency check). Per the SDM: If the logical processor is operating with Intel PT enabled (if IA32_RTIT_CTL.TraceEn = 1) at the time of VM entry, the "load IA32_RTIT_CTL" VM-entry control must be 0. On the host side, KVM doesn't validate the guest CPUID configuration provided by userspace, and even worse, uses the guest configuration to decide what MSRs to save/load at VM-Enter and VM-Exit. E.g. configuring guest CPUID to enumerate more address ranges than are supported in hardware will result in KVM trying to passthrough, save, and load non-existent MSRs, which generates a variety of WARNs, ToPA ERRORs in the host, a potential deadlock, etc.

Frequently asked questions

What is CVE-2024-53135?
In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Bury Intel PT virtualization (guest/host mode) behind CONFIG_BROKEN Hide KVM's pt_mode module param behind CONFIG_BROKEN, i.e. disable support for virtualizing Intel PT via guest/host mode unless BROKEN=y. There are myriad bugs in the implementation, some of which are fatal to the guest, and others which put the stability and health of the host at risk. For guest fatalities, the most glaring issue is that KVM fails to ensure tracing is disabled, and *stays* disabled prior to VM-Enter, which is necessary as hardware disallows loading (the guest's) RTIT_CTL if tracing is enabled (enforced via a VMX consistency check). Per the SDM: If the logical processor is operating with Intel PT enabled (if IA32_RTIT_CTL.TraceEn = 1) at the time of VM entry, the "load IA32_RTIT_CTL" VM-entry control must be 0. On the host side, KVM doesn't validate the guest CPUID configuration provided by userspace, and even worse, uses the guest configuration to decide what MSRs to save/load at VM-Enter and VM-Exit. E.g. configuring guest CPUID to enumerate more address ranges than are supported in hardware will result in KVM trying to passthrough, save, and load non-existent MSRs, which generates a variety of WARNs, ToPA ERRORs in the host, a potential deadlock, etc.
How severe is CVE-2024-53135?
CVE-2024-53135 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2024-53135 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-53135?
CVE-2024-53135 primarily affects Linux Linux Kernel. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-53135?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-53135 have an EU (EUVD) identifier?
Yes. CVE-2024-53135 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-51807.
When was CVE-2024-53135 published?
CVE-2024-53135 was published on 2024-12-04 and last updated on 2026-06-17.

References

Affected products (8)

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