| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-53135: KVM: VMX: Bury Intel PT virtualization (guest/host mode) behind CONFIG_BROKEN |
| |
| 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. |
| |
| The Linux kernel CVE team has assigned CVE-2024-53135 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.0 with commit f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 and fixed in 5.4.287 with commit c3742319d021f5aa3a0a8c828485fee14753f6de |
| Issue introduced in 5.0 with commit f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 and fixed in 5.10.231 with commit d4b42f926adcce4e5ec193c714afd9d37bba8e5b |
| Issue introduced in 5.0 with commit f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 and fixed in 5.15.174 with commit b8a1d572478b6f239061ee9578b2451bf2f021c2 |
| Issue introduced in 5.0 with commit f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 and fixed in 6.1.119 with commit e6716f4230a8784957273ddd27326264b27b9313 |
| Issue introduced in 5.0 with commit f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 and fixed in 6.6.63 with commit d28b059ee4779b5102c5da6e929762520510e406 |
| Issue introduced in 5.0 with commit f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 and fixed in 6.11.10 with commit b91bb0ce5cd7005b376eac690ec664c1b56372ec |
| Issue introduced in 5.0 with commit f99e3daf94ff35dd4a878d32ff66e1fd35223ad6 and fixed in 6.12 with commit aa0d42cacf093a6fcca872edc954f6f812926a17 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-53135 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| arch/x86/kvm/vmx/vmx.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| 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 |
