CVE-2026-97960perf/x86/intel: Prevent drain_pebs() reentry

In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Prevent drain_pebs() reentry The PEBS buffer is shared by all events on a CPU, so drain_pebs() must not be reentered. If so, one instance may observe stale buffer state and potentially access out-of-bound memory. Most invocations happen in NMI context, which naturally prevents reentry. However, drain_pebs() is also reachable from process context via intel_pmu_drain_pebs_buffer(). In those paths, the PMU is often already disabled, but not guaranteed. For example, __intel_pmu_pebs_disable() only disables the target counter, so other active counters can still raise a PMI and interrupt an in-flight drain_pebs(). Here is an example, __perf_addr_filters_adjust() perf_event_stop() __perf_event_stop() x86_pmu_stop() (event->pmu->stop) intel_pmu_disable_event() intel_pmu_pebs_disable() __intel_pmu_pebs_disable() intel_pmu_drain_large_pebs() intel_pmu_drain_pebs_buffer() Introduce __intel_pmu_quiesce() and __intel_pmu_resume() helpers and use them in intel_pmu_drain_large_pebs() to disable the full PMU around the intel_pmu_drain_pebs_buffer() call, preventing reentry. Also add a warning in intel_pmu_drain_pebs_buffer() when the full PMU is not disabled.

CVSS

Not yet scored

Weakness (CWE)

Not given

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

Linux

NVD analysis

Received

Record last updated

Oct 19, 2026

First seen by InfoSec Signals

Oct 9, 2026

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