# CVE-2025-40061: RDMA/rxe: Fix race in do_task() when draining

> A race condition in the Linux kernel RDMA driver allows a use-after-free, potentially enabling local attackers to execute code or escalate privileges.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 28 Oct 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-68837, BELL-CVE-2025-40061, DEBIAN-CVE-2025-40061, GHSA-c64c-4m7r-82v9, ROOT-OS-DEBIAN-13-CVE-2025-40061, ROOT-OS-UBUNTU-2404-CVE-2025-40061, UBUNTU-CVE-2025-40061

## What is CVE-2025-40061?

CVE-2025-40061 is a high-severity vulnerability in Linux, published on 28 Oct 2025. 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:

RDMA/rxe: Fix race in do_task() when draining

When do_task() exhausts its iteration budget (!ret), it sets the state
to TASK_STATE_IDLE to reschedule, without a secondary check on the
current task->state. This can overwrite the TASK_STATE_DRAINING state
set by a concurrent call to rxe_cleanup_task() or rxe_disable_task().

While state changes are protected by a spinlock, both rxe_cleanup_task()
and rxe_disable_task() release the lock while waiting for the task to
finish draining in the while(!is_done(task)) loop. The race occurs if
do_task() hits its iteration limit and acquires the lock in this window.
The cleanup logic may then proceed while the task incorrectly
reschedules itself, leading to a potential use-after-free.

This bug was introduced during the migration from tasklets to workqueues,
where the special handling for the draining case was lost.

Fix this by restoring the original pre-migration behavior. If the state is
TASK_STATE_DRAINING when iterations are exhausted, set cont to 1 to
force a new loop iteration. This allows the task to finish its work, so
that a subsequent iteration can reach the switch statement and correctly
transition the state to TASK_STATE_DRAINED, stopping the task as intended.

## Which versions are affected by CVE-2025-40061?


## How do I fix CVE-2025-40061?

Apply the vendor's patch.

## Is CVE-2025-40061 being exploited?

There is no known exploitation of CVE-2025-40061 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40061 and fix it if it is affected.

What it is: CVE-2025-40061 is a high-severity vulnerability in Linux, published on 28 Oct 2025. 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-2025-40061 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-2025-40061/ (Markdown: https://insights.sbomify.com/CVE-2025-40061/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40061
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40061
- OSV: https://osv.dev/vulnerability/CVE-2025-40061

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40061/
Summaries are generated and may contain mistakes; the official description above is the record.