CVE-2023-52776

What it actually does

Missing RCU read-side critical section around ath12k_mac_get_ar_by_pdev_id calls in DFS-radar and temperature event handlers allows potential use-after-free of active pdev structures protected only by RCU.

Why it matters to the business

Affected Linux systems using ath12k Wi-Fi hardware may experience kernel crashes or instability during radar or thermal events; urgency remains low given absence from known exploitation lists and minimal exploit probability.

How an attack unfolds

An attacker with local access or the ability to trigger DFS-radar/temperature events would race pdev teardown against the unprotected lookup to induce a use-after-free; no named threat actors or public exploits are associated with this issue.

How to fix it

Upgrade the linux package on Debian 11 to version 5.10.197-1 or newer; rebuild and reboot with the patched kernel; apply the same update across all affected distributions shipping ath12k.

How to confirm the fix worked

Confirm the running kernel version is at least 5.10.197-1, verify the ath12k source contains the RCU read-lock annotations around the event handlers, and ensure no RCU lockdep warnings are emitted for ath12k_mac_get_ar_by_pdev_id during radar or temperature events.

Typical attack path

1. Obtain local execution or control over Wi-Fi event generation on an ath12k-equipped system
2. Trigger DFS-radar or temperature event paths while concurrently initiating pdev removal
3. Trigger the unprotected ath12k_mac_get_ar_by_pdev_id call to dereference a freed object
4. Leverage the resulting use-after-free for memory corruption or denial of service

How to detect it

Review kernel logs for ath12k RCU lockdep splats or use-after-free crashes referencing ath12k_mac_get_ar_by_pdev_id; inspect dmesg and journalctl for pdev-related warnings during radar or temperature events.

What your security team should do

• Prioritize patching Debian 11 systems to linux 5.10.197-1 within standard maintenance windows
• Monitor for ath12k-related kernel oops or RCU warnings in production Wi-Fi workloads
• Inventory all devices using ath12k hardware and schedule kernel updates accordingly