CVE-2026-93150: cgroup/cpuset: Make nr_deadline_tasks an atomic_t
cgroup/cpuset: Make nrdeadlinetasks an atomict
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Patch 6c24849f5515 - Configuration
Change nr_deadline_tasks in the cpuset structure to atomic_t (per patch “cgroup/cpuset: Make nr_deadline_tasks an atomic_t”) to ensure updates are atomic and avoid corruption from concurrent sched/cpuset interactions.
Linux kernel cpuset nr_deadline_tasks type = atomic_t
Event History
Frequently Asked Questions
What conditions are needed for the counter corruption to occur?
The issue requires concurrent updates to a cpuset's nr_deadline_tasks counter: one through inc_dl_tasks_cs() while holding rq->lock and another through cpuset_attach() while holding cpuset_mutex. The described race includes concurrent sched_setscheduler() and cpuset_can_attach()/cpuset_attach() activity involving SCHED_DEADLINE tasks.
What is the practical effect of a successful race?
Concurrent non-atomic updates can corrupt the nr_deadline_tasks value in a cpuset. This can cause incorrect operations later that rely on that counter.
Does the referenced fix address every related scheduling and cpuset race?
No. Changing nr_deadline_tasks to atomic_t handles some races involving concurrent sched_setscheduler() and cpuset attachment operations, but the description states that other related races remain for a future follow-up patch.