Bug 2525489 (CVE-2026-80623)

Summary:	CVE-2026-80623 kernel: coresight: ete: Always save state on power down
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Coresight Embedded Trace Extension (ETE) component of the Linux kernel. This vulnerability arises because the system register states for Embedded Trace Macrocells (ETMs) and ETE are not consistently preserved when the CPU powers down. A local attacker could potentially trigger this condition by interacting with CPU power management, which may lead to system instability or a denial of service due to improper state handling and resource management.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-08-28 07:47:37 UTC

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

Comment 1 gkamathe 2026-08-31 15:37:54 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082837-CVE-2026-80623-4b72@gregkh/T