CVE-2024-27053

What it actually does

Improper RCU pointer dereference outside an RCU read-side critical section in wilc_parse_join_bss_param during cfg80211 connect handling, allowing potential concurrent modification of BSS IEs and parameters in the wilc1000 WiFi driver.

Why it matters to the business

WiFi instability, kernel warnings, crashes, or failed connections on systems using the wilc1000 chipset, increasing downtime for embedded or IoT Linux deployments; low exploitation likelihood but high severity if triggered under load.

How an attack unfolds

An attacker with local or network-adjacent access triggers repeated WiFi connect operations (via wpa_supplicant or similar) while other driver paths modify BSS data, racing the unprotected RCU dereference to cause memory corruption or denial of service.

How to fix it

Update the Linux kernel to a version containing commit e556006de4ea93abe2b46cba202a2556c544b8b2 which wraps the ies data copy inside an RCU read critical section; rebuild and reboot affected systems.

How to confirm the fix worked

Verify kernel source contains the RCU read lock around the ies copy in wilc_parse_join_bss_param; confirm absence of the suspicious RCU usage warning under lockdep during connect operations; test WiFi association stability.

Typical attack path

1. Obtain local or WiFi-adjacent access to target Linux system with wilc1000 hardware
2. Initiate or force repeated cfg80211 connect requests via userspace tools
3. Race with driver BSS scanning or parameter updates to hit unprotected RCU access
4. Trigger suspicious RCU usage leading to kernel warning, crash, or data corruption

How to detect it

Search kernel logs (dmesg, journalctl) for the exact RCU warning string and stack trace involving wilc_parse_join_bss_param and cfg80211_connect; correlate with WiFi connect attempts from wpa_supplicant.

• suspicious rcu_dereference_check() usage!
• wilc_parse_join_bss_param from connect+0x2c4/0x648
• CPU:.*PID:.*Comm: wpa_supplicant.*wilc1000

What your security team should do

• Prioritize kernel update on all wilc1000-based devices within maintenance windows
• Monitor for RCU warnings in dmesg on affected systems until patched
• Limit exposure by disabling unnecessary WiFi if updates cannot be applied promptly
• Track downstream kernel package updates in distributions using the stable tree