# CVE-2026-74407: wifi: ath11k: cancel SSR work items during PCI shutdown

> A race condition in the ath11k WiFi driver during PCI shutdown can cause a kernel crash via NULL pointer dereference.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 15 Aug 2026
- **Updated:** 21 Oct 2026
- **Also known as:** BELL-CVE-2026-74407, DEBIAN-CVE-2026-74407, GHSA-r6wh-wch9-fxjr, UBUNTU-CVE-2026-74407

## What is CVE-2026-74407?

CVE-2026-74407 is a high-severity vulnerability in Linux, published on 15 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:

wifi: ath11k: cancel SSR work items during PCI shutdown

A reboot can crash the kernel if it overlaps with WLAN firmware crash
recovery (SSR). The crash is a NULL pointer dereference in the MHI teardown
path while freeing DMA-backed MHI contexts.

Simplified trace:
  dma_free_attrs
  mhi_deinit_dev_ctxt [mhi]
  ath11k_pci_power_down [ath11k_pci]
  ath11k_pci_shutdown [ath11k_pci]
  device_shutdown
  kernel_restart

On the host side, SSR is driven by the MHI RDDM callback, which queues
reset_work to perform device recovery. reset_work power-cycles the device
by calling ath11k_hif_power_down() followed by ath11k_hif_power_up(). The
power-down phase deinitializes MHI and frees DMA resources.

Shutdown/reboot runs fully asynchronously with this RDDM-driven SSR
recovery flow. As a result, the shutdown path
(ath11k_pci_shutdown() -> ath11k_pci_power_down()) can race with the SSR
recovery sequence.

Fix this by canceling SSR-related work items during PCI shutdown, marking
the device as unregistering, and serializing the RDDM callback path that
checks and queues reset_work. This ensures that no new SSR recovery work
can be queued once teardown has started, and that any in-flight recovery
work is fully synchronized before device power-down, preventing MHI
teardown and DMA resource freeing from running more than once.

Note: This issue only affects PCI/MHI-based devices. AHB-based ath11k
devices do not queue reset_work in normal SSR flows.

Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-04866.5-QCAHSPSWPL_V1_V2_SILICONZ_IOE-1

## Which versions are affected by CVE-2026-74407?


## How do I fix CVE-2026-74407?

Apply the vendor's patch.

## Is CVE-2026-74407 being exploited?

There is no known exploitation of CVE-2026-74407 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74407 and fix it if it is affected.

What it is: CVE-2026-74407 is a high-severity vulnerability in Linux, published on 15 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-2026-74407 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-2026-74407/ (Markdown: https://insights.sbomify.com/CVE-2026-74407/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74407
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74407
- OSV: https://osv.dev/vulnerability/CVE-2026-74407

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74407/
Summaries are generated and may contain mistakes; the official description above is the record.