CVE-2026-80623 coresight: ete: Always save state on power down
A Linux kernel bug in Coresight ETE handling causes system warnings and potential instability during CPU power down, requiring a kernel patch.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80623?
CVE-2026-80623 is a denial of service vulnerability in Linux, published on 28 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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
Which versions are affected by CVE-2026-80623?
How do I fix CVE-2026-80623?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-80623 being exploited?
There is no known exploitation of CVE-2026-80623 in the wild and no public exploit code.
Sources
Also known as AZL-98054, BELL-CVE-2026-80623, DEBIAN-CVE-2026-80623, GHSA-6v36-jxjj-2vq8, UBUNTU-CVE-2026-80623.