CVE Catalog

CVE-2026-64556

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.12%

2th percentile - higher than 2% of all known CVEs

Summary

In the Linux kernel, a vulnerability was found in the perf event group management. Removing events via perf_event_remove_on_exec() can leave an inconsistent group state when a group leader is removed while sibling events remain active. This corrupts the PMU context active list and can cause a double list addition.

Risk Assessment

The organization risks system crashes or unpredictable performance monitoring behavior, potentially leading to downtime of critical services.

Recommendation

Immediately update the Linux kernel to a version containing the fix for this vulnerability.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: perf/core: Detach event groups during remove_on_exec perf_event_remove_on_exec() removes events by calling perf_event_exit_event(). For top-level events, this removes the event from the context with DETACH_EXIT only. This can leave inconsistent group state when a removed event is a group leader and the group contains siblings without remove_on_exec. If the group was active, the surviving siblings can remain active and attached to the removed leader's sibling list, but are no longer represented by a valid group leader on the PMU context active lists. A later close of the removed leader uses DETACH_GROUP and can promote the still-active siblings from this stale group state. The next schedule-in can then add an already-linked active_list entry again, corrupting the PMU context active list. With DEBUG_LIST enabled, this is caught as a list_add double-add in merge_sched_in(). Fix this by detaching group relationships when remove_on_exec removes an event. This preserves the existing task-exit and revoke behavior, while ensuring surviving siblings are ungrouped before the removed event leaves the context.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS