# CVE-2026-80647: RDMA/hns: Fix warning in poll cq direct mode

> A flaw in the Linux kernel RDMA driver triggers a warning during device reset, potentially causing system instability or denial of service.

- **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:** 28 Aug 2026
- **Updated:** 28 Aug 2026
- **Also known as:** BELL-CVE-2026-80647, DEBIAN-CVE-2026-80647, GHSA-3vgv-6mgp-cc8p, UBUNTU-CVE-2026-80647

## What is CVE-2026-80647?

CVE-2026-80647 is a denial of service vulnerability in Linux, published on 28 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:

RDMA/hns: Fix warning in poll cq direct mode

CQs allocated by ib_alloc_cq() always have a comp_handler. Though
in direct mode this handler is never expected to be called, it
is still called when the driver is reset, triggering the following
WARN_ONCE():

Call trace:
ib_cq_completion_direct+0x38/0x60
hns_roce_cq_completion+0x54/0x90 (hns_roce_hw_v2]
hns_roce_handle_device_err+Ox1c8/0x340 [hns_roce_hw_v2]
hns_roce_hw_v2_uninit_instance.constprop.0+0x34/0x70 [hns_roce_hw_v2]
hns_roce_hw_v2_reset_notify+0xc4/0xe0 [hns_roce_hw_v2]
hclge_notify_roce_client+0x60/0xbc [hclge]
hclge_reset_rebuild+0x48/0x34c [hclge]
hclge_reset_subtask+0xcc/0xec [hclge]
hclge_reset_service_task+0x80/0x160 [hclge]
hclge_service_task+0x50/0x80 (hclge]
process_one_work+0x1cc/0x4d0
worker_thread+0x154/0x414
kthread+0x104/0x144
ret_from_fork+0x10/0x18

## Which versions are affected by CVE-2026-80647?


## How do I fix CVE-2026-80647?

Apply the vendor's patch.

## Is CVE-2026-80647 being exploited?

There is no known exploitation of CVE-2026-80647 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80647 and fix it if it is affected.

What it is: CVE-2026-80647 is a denial of service vulnerability in Linux, published on 28 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-2026-80647 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-2026-80647/ (Markdown: https://insights.sbomify.com/CVE-2026-80647/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80647
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80647
- OSV: https://osv.dev/vulnerability/CVE-2026-80647

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80647/
Summaries are generated and may contain mistakes; the official description above is the record.