CVE-2022-50880 in Linux
Zusammenfassung
von VulDB • 02.06.2026
Based on the kernel log snippet provided, here is an analysis of the issue, its cause, and potential solutions.
### **Summary of the Issue** This is a **Use-After-Free (UAF)** or **Double-Free** bug in the `ath10k` Wi-Fi driver (specifically the `ath10k_core` module). The kernel's **KFENCE** memory safety detector has identified that a memory block (`kmalloc-2k`) was accessed or freed after it had already been freed.
The crash occurs during the **deauthentication process** (`ieee80211_mgd_deauth`), which triggers cleanup of station info (`__sta_info_destroy_part2`). However, the memory being accessed was originally allocated during a **peer map event** (`ath10k_peer_map_event`), which is part of the firmware-to-host message handling path.
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### **Detailed Breakdown**
#### **1. The Crash Context** - **Trigger:** A deauthentication request was sent via `nl80211_deauthenticate` → `cfg80211_mlme_deauth` → `ieee80211_mgd_deauth`. - **Cleanup:** The kernel is tearing down the station info (`__sta_info_flush` → `__sta_info_destroy_part2`). - **Driver Action:** The `ath10k` driver is involved in `drv_sta_state`, which likely tries to clean up or access hardware-specific data associated with the station.
#### **2. The KFENCE Alert** - **Error:** `kfence-#69: 0x000000009149b0d5-0x000000004c0697fb, size=1064, cache=kmalloc-2k` - KFENCE detected an invalid memory access. - The memory block was allocated from the `kmalloc-2k` cache. - **Allocation Source:** ``` allocated by task 13 on cpu 0 at 21705.501373s: ath10k_peer_map_event+0x7e/0x154 [ath10k_core]
ath10k_htt_t2h_msg_handler+0x586/0x1039 [ath10k_core]
... ``` - The memory was allocated in `ath10k_peer_map_event`, which handles messages from the Wi-Fi firmware (T2H = Target-to-Host). - This suggests that the firmware sent a "peer map" event, and the driver allocated memory to track this peer/station.
#### **3. The Root Cause Hypothesis** The most likely scenario is a **race condition** or **state mismatch**: 1. The firmware sends a `peer_map_event` (e.g., a new station connects or is mapped). 2. The driver allocates memory in `ath10k_peer_map_event` to store peer information. 3. **Before** the driver finishes processing or properly references this memory, a deauthentication event occurs (either from user space or firmware). 4. The deauthentication path frees the station info and associated memory. 5. Later, when the driver tries to access or free the memory allocated in step 2 (perhaps in a deferred work item or another firmware message handler), it accesses already-freed memory → **UAF**.
Alternatively, the memory might be **double-freed**: - The memory is freed once during `__sta_info_destroy_part2`. - It is freed again later when `ath10k_peer_map_event` or a related cleanup routine tries to free it again.
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### **Potential Solutions & Workarounds**
#### **1. Update Kernel and Drivers** - This is a known class of bugs in older `ath10k` drivers. Check if your kernel version is up-to-date. - Look for commits related to `ath10k` peer management, `sta_info` cleanup, or KFENCE fixes in your kernel version's changelog. - **Action:** Upgrade to the latest stable kernel (e.g., 6.1+ or 6.6+ LTS) if possible.
#### **2. Disable Power Management for the Wi-Fi Card** - Power management can exacerbate race conditions between firmware and driver. - **Action:** Add `options ath10k_core disable_hw_scan=1` or `options ath10k_core ps_enable=0` to `/etc/modprobe.d/ath10k.conf` and reboot.
#### **3. Avoid Rapid Connect/Disconnect Cycles** - If this happens during frequent reconnections, try
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