Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 before c3742319d021f5aa3a0a8c828485fee14753f6de; affected f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 before d4b42f926adcce4e5ec193c714afd9d37bba8e5b; affected f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 before b8a1d572478b6f239061ee9578b2451bf2f021c2; affected f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 before e6716f4230a8784957273ddd27326264b27b9313; affected f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 before d28b059ee4779b5102c5da6e929762520510e406; affected f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 before b91bb0ce5cd7005b376eac690ec664c1b56372ec; affected f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 before aa0d42cacf093a6fcca872edc954f6f812926a17 |
| Linux / Linux | affected 5.0; unaffected 0 before 5.0; unaffected 5.4.287 through 5.4.*; unaffected 5.10.231 through 5.10.*; unaffected 5.15.174 through 5.15.*; unaffected 6.1.119 through 6.1.*; unaffected 6.6.63 through 6.6.*; unaffected 6.11.10 through 6.11.*; unaffected 6.12 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/c3742319d021f5aa3a0a8c828485fee14753f6de
- https://git.kernel.org/stable/c/d4b42f926adcce4e5ec193c714afd9d37bba8e5b
- https://git.kernel.org/stable/c/b8a1d572478b6f239061ee9578b2451bf2f021c2
- https://git.kernel.org/stable/c/e6716f4230a8784957273ddd27326264b27b9313
- https://git.kernel.org/stable/c/d28b059ee4779b5102c5da6e929762520510e406
- https://git.kernel.org/stable/c/b91bb0ce5cd7005b376eac690ec664c1b56372ec
- https://git.kernel.org/stable/c/aa0d42cacf093a6fcca872edc954f6f812926a17
ADP enrichment
No English description supplied.
No English description supplied.
No references supplied.