Linux Kernel ath11k Deadlock Vulnerability Leading to Management Frame Transmission Issues

A vulnerability in the Linux kernel's ath11k wireless driver has been addressed, which caused a deadlock preventing the proper flushing of management frames in the transmission queue. This issue led to warnings about blocked tasks and dropped management frames, disrupting normal wireless communication. The deadlock occurred because the management transmission work was unable to execute for an extended period, causing delays and frame loss.

Impact

The vulnerability caused a deadlock that blocked the wpa_supplicant task for over 20 seconds, disrupting the management frame transmission process and leading to dropped frames, which can interfere with wireless communication and network management tasks.

Reproduction

The vulnerability can be reproduced by setting the kernel's hung task timeout to 20 seconds, which will trigger a warning if a task is blocked longer than that. Then, increase the ATH11K_FLUSH_TIMEOUT to 50 seconds. Under these conditions, the ath11k driver will fail to flush management frames, causing wpa_supplicant to become blocked and generating warnings about the delayed task.