CVE-2026-80623
Received Received - Intake

Coresight ETE State Loss on CPU Power Down

Publication date: 2026-08-28

Last updated on: 2026-08-28

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: coresight: ete: Always save state on power down System register ETMs and ETE are unlikely to be preserved on CPU power down. The ETE DT binding also never documented "arm,coresight-loses-context-with-cpu" so nobody would have legitimately been able to use that binding to fix it and ACPI has no such binding at all. Fix it by hard coding the setting for sysreg ETMs (ETE is always sysreg) or ACPI boots. Use a local variable when setting up save_state so that it's immune to concurrent probing when devices have different configurations which is an issue with modifying the global. This fixes the following error when using Coresight with ACPI on the FVP which supports CPU PM: coresight ete0: External agent took claim tag WARNING: drivers/hwtracing/coresight/coresight-core.c:248 at coresight_disclaim_device_unlocked+0xe0/0xe8, CPU#0: perf/117

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Meta Information

Published
2026-08-28
Last Modified
2026-08-28
Generated
2026-09-17
AI Q&A
2026-08-28
EPSS Evaluated
2026-09-15
NVD
CVE-2026-80623
EUVD
EUVD-2026-67499

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
arm coresight *

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Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves Coresight ETE (Embedded Trace Extension) not properly saving its state when a CPU powers down. The issue occurs because system register ETMs and ETE are unlikely to be preserved during CPU power down events. The fix ensures state is always saved by hardcoding the setting for sysreg ETMs or ACPI boots, addressing a problem where the ETE DT binding did not document this behavior.

Detection Guidance

This vulnerability is specific to the Linux kernel's Coresight ETE/ETM tracing functionality and may not have direct network detection methods. Check kernel logs for errors related to coresight or ETE devices using commands like 'dmesg | grep coresight' or 'journalctl -k | grep coresight'.

Impact Analysis

This vulnerability may cause errors like 'External agent took claim tag' when using Coresight with ACPI on certain systems (e.g., FVP). It could lead to tracing failures or data corruption during CPU power management operations, potentially disrupting debugging or performance monitoring tools that rely on Coresight.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It is a low-level hardware tracing issue in the Linux kernel related to CPU power management and Coresight debugging features. There is no indication it impacts data privacy, security controls, or regulatory requirements.

Mitigation Strategies

Apply the latest Linux kernel update that includes the fix for this CVE. If using ACPI or sysreg-based Coresight, ensure the kernel version includes the patch for 'coresight: ete: Always save state on power down'.

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