# CVE-2026-68191: wifi: ath12k: fix NULL pointer dereference in rhash table destroy

> A NULL pointer dereference in the ath12k Wi-Fi driver during device unbinding can cause a kernel crash, leading to 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:** 10 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-68191, GHSA-fcf7-j5wv-2rxv, UBUNTU-CVE-2026-68191

## What is CVE-2026-68191?

CVE-2026-68191 is a 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:

wifi: ath12k: fix NULL pointer dereference in rhash table destroy

When unbinding the ath12k driver, kernel NULL pointer dereferences
occur in irq_work_sync() called from rhashtable_destroy().

Two hash tables are affected:
1. ath12k_link_sta hash table in ath12k_base
2. ath12k_dp_link_peer hash table in ath12k_dp

The issue happens because the destroy functions are called unconditionally
in cleanup paths, but the hash tables are only initialized late in their
respective init functions. If the device was never fully started or if the
init functions failed before initializing the hash tables, the pointers
will be NULL. The issues are always reproducible from a VM because the MSI
addressing initialization is failing.

Call trace for ath12k_link_sta_rhash_tbl_destroy:
 RIP: irq_work_sync+0x1e/0x70
 rhashtable_destroy+0x12/0x60
 ath12k_link_sta_rhash_tbl_destroy+0x19/0x40 [ath12k]
 ath12k_core_stop+0xe/0x80 [ath12k]
 ath12k_core_hw_group_cleanup+0x6b/0xb0 [ath12k]
 ath12k_pci_remove+0x60/0x110 [ath12k]

Call trace for ath12k_dp_link_peer_rhash_tbl_destroy:
 RIP: irq_work_sync+0x1e/0x70
 rhashtable_destroy+0x12/0x60
 ath12k_dp_link_peer_rhash_tbl_destroy+0x29/0x50 [ath12k]
 ath12k_dp_cmn_device_deinit+0x21/0x140 [ath12k]
 ath12k_core_hw_group_cleanup+0x6b/0xb0 [ath12k]
 ath12k_pci_remove+0x60/0x110 [ath12k]

Fix this by adding NULL checks before calling rhashtable_destroy() in
both destroy functions.

The NULL check approach was chosen because the rhashtable pointer
serves as the initialization state indicator. The init can fail at
various points, leaving some components uninitialized. Checking the
pointer directly is simpler than adding separate state flags that
would need synchronization.

## Which versions are affected by CVE-2026-68191?


## How do I fix CVE-2026-68191?

Apply the vendor's patch.

## Is CVE-2026-68191 being exploited?

There is no known exploitation of CVE-2026-68191 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68191 and fix it if it is affected.

What it is: CVE-2026-68191 is a 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-2026-68191 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-2026-68191/ (Markdown: https://insights.sbomify.com/CVE-2026-68191/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68191
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68191
- OSV: https://osv.dev/vulnerability/CVE-2026-68191

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68191/
Summaries are generated and may contain mistakes; the official description above is the record.