# CVE-2026-89527: svcrdma: Use svc_xprt_put to free listener on create failure

> A use-after-free vulnerability in the Linux kernel's svcrdma module allows attackers to cause a denial of service or potentially execute code via crafted network traffic.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-100404, BELL-CVE-2026-89527, DEBIAN-CVE-2026-89527, GHSA-h2xv-x4xq-mhh8, UBUNTU-CVE-2026-89527

## What is CVE-2026-89527?

CVE-2026-89527 is an use after free vulnerability in Linux, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

svcrdma: Use svc_xprt_put to free listener on create failure

svc_rdma_create() calls kfree(cma_xprt) when
svc_rdma_create_listen_id() fails. svc_xprt_init() has already
acquired a net namespace reference via get_net_track(); kfree
bypasses svc_xprt_free() which releases it.

Replace the kfree() with svc_xprt_put() so the kref_init birth
reference drops to zero and svc_xprt_free() dispatches
svc_rdma_free() to clean up properly. sc_cm_id is still NULL
at that point; the preceding patch added the necessary NULL
guard in svc_rdma_free().

svc_xprt_free() also drops the module reference via
module_put(), but the caller _svc_xprt_create() does the same
on xpo_create failure, double-putting the single
try_module_get() it acquired. Take a compensating
__module_get() before the svc_xprt_put() to keep the count
balanced, matching the convention in svc_rdma_accept()'s error
path.

## Which versions are affected by CVE-2026-89527?


## How do I fix CVE-2026-89527?

Apply the vendor's patch.

## Is CVE-2026-89527 being exploited?

There is no known exploitation of CVE-2026-89527 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89527 and fix it if it is affected.

What it is: CVE-2026-89527 is an use after free vulnerability in Linux, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-89527 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-2026-89527/ (Markdown: https://insights.sbomify.com/CVE-2026-89527/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89527
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89527
- OSV: https://osv.dev/vulnerability/CVE-2026-89527

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89527/
Summaries are generated and may contain mistakes; the official description above is the record.