# CVE-2025-38606: wifi: ath12k: Avoid accessing uninitialized arvif->ar during beacon miss

> A null pointer dereference in the ath12k WiFi driver during beacon miss handling can cause a kernel crash, leading to denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 19 Aug 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-38606, GHSA-2hfg-pw5c-5cwc, UBUNTU-CVE-2025-38606

## What is CVE-2025-38606?

CVE-2025-38606 is a medium-severity vulnerability in Linux kernel, published on 19 Aug 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:

wifi: ath12k: Avoid accessing uninitialized arvif->ar during beacon miss

During beacon miss handling, ath12k driver iterates over active virtual
interfaces (vifs) and attempts to access the radio object (ar) via
arvif->deflink->ar.

However, after commit aa80f12f3bed ("wifi: ath12k: defer vdev creation for
MLO"), arvif is linked to a radio only after vdev creation, typically when
a channel is assigned or a scan is requested.
For P2P capable devices, a default P2P interface is created by
wpa_supplicant along with regular station interfaces, these serve as dummy
interfaces for P2P-capable stations, lack an associated netdev and initiate
frequent scans to discover neighbor p2p devices. When a scan is initiated
on such P2P vifs, driver selects destination radio (ar) based on scan
frequency, creates a scan vdev, and attaches arvif to the radio. Once the
scan completes or is aborted, the scan vdev is deleted, detaching arvif
from the radio and leaving arvif->ar uninitialized.

While handling beacon miss for station interfaces, P2P interface is also
encountered in the vif iteration and ath12k_mac_handle_beacon_miss_iter()
tries to dereference the uninitialized arvif->deflink->ar.

Fix this by verifying that vdev is created for the arvif before accessing
its ar during beacon miss handling and similar vif iterator callbacks.

==========================================================================
 wlp6s0: detected beacon loss from AP (missed 7 beacons) - probing
 KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]

 CPU: 5 UID: 0 PID: 0 Comm: swapper/5 Not tainted 6.16.0-rc1-wt-ath+ #2 PREEMPT(full)
 RIP: 0010:ath12k_mac_handle_beacon_miss_iter+0xb5/0x1a0 [ath12k]
 Call Trace:
  __iterate_interfaces+0x11a/0x410 [mac80211]
  ieee80211_iterate_active_interfaces_atomic+0x61/0x140 [mac80211]
  ath12k_mac_handle_beacon_miss+0xa1/0xf0 [ath12k]
  ath12k_roam_event+0x393/0x560 [ath12k]
  ath12k_wmi_op_rx+0x1486/0x28c0 [ath12k]
  ath12k_htc_process_trailer.isra.0+0x2fb/0x620 [ath12k]
  ath12k_htc_rx_completion_handler+0x448/0x830 [ath12k]
  ath12k_ce_recv_process_cb+0x549/0x9e0 [ath12k]
  ath12k_ce_per_engine_service+0xbe/0xf0 [ath12k]
  ath12k_pci_ce_workqueue+0x69/0x120 [ath12k]
  process_one_work+0xe3a/0x1430

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00284.1-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2025-38606?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-38606?

Apply the vendor's patch.

## Is CVE-2025-38606 being exploited?

There is no known exploitation of CVE-2025-38606 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-38606 and fix it if it is affected.

What it is: CVE-2025-38606 is a medium-severity vulnerability in Linux kernel, published on 19 Aug 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-2025-38606 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2025-38606/ (Markdown: https://insights.sbomify.com/CVE-2025-38606/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38606
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38606
- OSV: https://osv.dev/vulnerability/CVE-2025-38606

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38606/
Summaries are generated and may contain mistakes; the official description above is the record.