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.
- 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
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
Which versions are affected by CVE-2025-38606?
It affects 1 product.
Products include 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
Sources
Also known as BELL-CVE-2025-38606, GHSA-2hfg-pw5c-5cwc, UBUNTU-CVE-2025-38606.