# CVE-2026-68094: sched_ext: Preserve rq tracking across local DSQ dispatch

> A flaw in the Linux kernel's sched_ext scheduler can cause a lockdep assertion failure and system crash during task dispatch, requiring local access and specific scheduler configurations.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-68094, GHSA-2r8m-gp54-6g6c, UBUNTU-CVE-2026-68094

## What is CVE-2026-68094?

CVE-2026-68094 is a denial of service vulnerability in Linux, published on 10 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:

sched_ext: Preserve rq tracking across local DSQ dispatch

dispatch_to_local_dsq() can run from scx_bpf_dsq_move_to_local() while
ops.dispatch() has recorded the current rq. Moving a task to a local DSQ
may switch to the source or destination rq before synchronously invoking
ops.dequeue() through the following path:

  SCX_CALL_OP(dispatch, rq)
    ops.dispatch()
      scx_bpf_dsq_move_to_local()
        scx_flush_dispatch_buf()
          finish_dispatch()
            dispatch_to_local_dsq()
              scx_dispatch_enqueue()
                local_dsq_post_enq()
                  call_task_dequeue()
                    SCX_CALL_OP_TASK(dequeue, locked_rq, ...)

The nested callback saves the recorded rq and restores it on return. If
the rq tracking does not follow the lock switch, update_locked_rq() can
trigger the following lockdep assertion while restoring an rq which is
no longer held:

  WARNING: kernel/sched/sched.h:1641 at call_task_dequeue+0x160/0x170
  Call Trace:
    scx_dispatch_enqueue+0x2b0/0x460
    dispatch_to_local_dsq+0x138/0x230
    scx_flush_dispatch_buf+0x1af/0x220
    scx_bpf_dsq_move_to_local___v2+0xe2/0x1c0
    bpf__sched_ext_ops_dispatch+0x4b/0xa7
    do_pick_task_scx+0x3b6/0x910
    __pick_next_task+0x105/0x1f0
    __schedule+0x3e7/0x1980

Introduce switch_rq_lock() to update the tracking state together with
each rq lock handoff. Use it in dispatch_to_local_dsq(),
move_remote_task_to_local_dsq() and the in-balance paths of
scx_dsq_move(), ensuring that scx_locked_rq() consistently refers to the
rq whose lock is actually held throughout the lock dance.

## Which versions are affected by CVE-2026-68094?


## How do I fix CVE-2026-68094?

Apply the vendor's patch.

## Is CVE-2026-68094 being exploited?

There is no known exploitation of CVE-2026-68094 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68094 and fix it if it is affected.

What it is: CVE-2026-68094 is a denial of service vulnerability in Linux, published on 10 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-68094 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-68094/ (Markdown: https://insights.sbomify.com/CVE-2026-68094/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68094
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68094
- OSV: https://osv.dev/vulnerability/CVE-2026-68094

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68094/
Summaries are generated and may contain mistakes; the official description above is the record.