The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Red Hat Enterprise Linux - kernel: KVM: x86/pmu: Disable support for adaptive PEBS  Ubuntu Linux - In the     Linux kernel, the following vulnerability has been resolved: KVM: x86/pmu: Disable support for adaptive     PEBS Drop support for virtualizing adaptive PEBS, as KVM's implementation is architecturally broken     without an obvious/easy path forward, and because exposing adaptive PEBS can leak host LBRs to the guest,     i.e. can leak host kernel addresses to the guest. Bug #1 is that KVM doesn't account for the upper 32 bits     of IA32_FIXED_CTR_CTRL when (re)programming fixed counters, e.g fixed_ctrl_field() drops the upper bits,     reprogram_fixed_counters() stores local variables as u8s and truncates the upper bits too, etc. Bug #2 is     that, because KVM _always_ sets precise_ip to a non-zero value for PEBS events, perf will _always_     generate an adaptive record, even if the guest requested a basic record. Note, KVM will also enable     adaptive PEBS in individual *counter*, even if adaptive PEBS isn't exposed to the guest, but this is     benign as MSR_PEBS_DATA_CFG is guaranteed to be zero, i.e. the guest will only ever see Basic records. Bug     #3 is in perf. intel_pmu_disable_fixed() doesn't clear the upper bits either, i.e. leaves     ICL_FIXED_0_ADAPTIVE set, and intel_pmu_enable_fixed() effectively doesn't clear ICL_FIXED_0_ADAPTIVE     either. I.e. perf _always_ enables ADAPTIVE counters, regardless of what KVM requests. Bug #4 is that     adaptive PEBS *might* effectively bypass event filters set by the host, as Updated Memory Access Info     Group records information that might be disallowed by userspace via KVM_SET_PMU_EVENT_FILTER. Bug #5 is     that KVM doesn't ensure LBR MSRs hold guest values (or at least zeros) when entering a vCPU with adaptive     PEBS, which allows the guest to read host LBRs, i.e. host RIPs/addresses, by enabling LBR Entries     records. Disable adaptive PEBS support as an immediate fix due to the severity of the LBR leak in     particular, and because fixing all of the bugs will be non-trivial, e.g. not suitable for backporting to     stable kernels. Note! This will break live migration, but trying to make KVM play nice with live migration     would be quite complicated, wouldn't be guaranteed to work (i.e. KVM might still kill/confuse the guest),     and it's not clear that there are any publicly available VMMs that support adaptive PEBS, let alone live     migrate VMs that support adaptive PEBS, e.g. QEMU doesn't support PEBS in any capacity. (CVE-2024-26992)

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Linux Distros Unpatched Vulnerability : CVE-2024-26992

low Nessus Plugin ID 227792

Version 1.6