CVE-2026-93150 cgroup/cpuset: Make nr_deadline_tasks an atomic_t

Not scored Published 17 Sep 2026 Updated 21 Oct 2026

A race condition in the Linux kernel cpuset subsystem can corrupt task counters, potentially leading to system instability or privilege escalation.

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-2026-93150?

CVE-2026-93150 is a 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:

cgroup/cpuset: Make nr_deadline_tasks an atomic_t

The nr_deadline_tasks variable in the cpuset structure was introduced by commit 6c24849f5515 ("sched/cpuset: Keep track of SCHED_DEADLINE task in cpusets"). It is reported by sashiko [1] that nr_deadline_tasks can currently be modified by inc_dl_tasks_cs() under rq->lock and by cpuset_attach() under cpuset_mutex. So if both updates happen simultaneously, the nr_deadline_tasks variable can be corrupted leading to incorrect operations down the road.

Fix that by changing its type to atomic_t so that nr_deadline_tasks are always atomically updated. This fix patch is a low hanging fruit. It can handle some of the races between a concurrent sched_setscheduler() and cpuset_can_attach()/cpuset_attach() calls, but not all of them like the other issue raised by sashiko [2]. This will be handled hopefully in a future follow up patch.

[1] https://sashiko.dev/#/patchset/20260626181923.133658-1-longman%40redhat.com [2] https://sashiko.dev/#/patchset/20260630033344.352702-1-longman%40redhat.com

Which versions are affected by CVE-2026-93150?

How do I fix CVE-2026-93150?

Apply the vendor's patch.

Is CVE-2026-93150 being exploited?

There is no known exploitation of CVE-2026-93150 in the wild and no public exploit code.

Sources

Also known as AZL-101855, BELL-CVE-2026-93150, DEBIAN-CVE-2026-93150, GHSA-rm22-rvmg-2466, UBUNTU-CVE-2026-93150.