CVE-2026-90273 coresight: etm4x: missing cscfg_csdev_disable_active_config() in perf enable
A missing function call in the Linux kernel's CoreSight ETM4x driver causes a reference count leak, potentially leading to resource exhaustion and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90273?
CVE-2026-90273 is a denial of service vulnerability in Linux, published on 17 Sep 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: etm4x: missing cscfg_csdev_disable_active_config() in perf enable
In the perf enable path, there are missing cases where cscfg_csdev_disable_active_config() is not called:
- Branch broadcast is selected but not supported by the hardware - etm4_enable_hw() fails
This can lead to a leak of config_desc->active_cnt. Fix this by properly calling cscfg_csdev_disable_active_config() in these error paths.
Which versions are affected by CVE-2026-90273?
How do I fix CVE-2026-90273?
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-2026-90273 being exploited?
There is no known exploitation of CVE-2026-90273 in the wild and no public exploit code.
Sources
Also known as AZL-102999, BELL-CVE-2026-90273, DEBIAN-CVE-2026-90273, GHSA-24qc-78x7-rfr3, UBUNTU-CVE-2026-90273.