Linux Kernel Vulnerability in Performance Monitoring Unit Event Management

CVE-2026-99187

What is CVE-2026-99187?

A vulnerability has been identified in the Linux kernel's performance monitoring unit (PMU) event management where the event migration process does not correctly track certain performance events after a CPU hotplug operation. The perf_pmu_migrate_context() function fails to properly remove events from the previous context, potentially leading to undesired PMU behavior. This issue can result in lingering events on a removed CPU while new PMU events continue on an active CPU, which may disrupt the expected functionality of drivers dependent on PMU operations.

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