The Linux kernel mwifiex wifi driver improperly handles power-save state transitions during association command responses. Specifically, the driver unconditionally sets the power-save state to AWAKE when processing association responses, even if the firmware is in a PRE_SLEEP state. This causes the deferred sleep-confirm command to never be sent, resulting in the firmware not generating scan_result events. Consequently, scan requests never complete and further scan attempts fail with -EBUSY. The issue was reproducible on the IW412 firmware variant under certain timing conditions but not on the W8997 variant. The fix removes the improper power-save state assignment to ensure correct sleep confirmation and scan completion.

Scan operations on affected devices can become permanently busy, preventing successful wifi scans after multiple roaming events. This can degrade wifi functionality by blocking new scan requests and potentially impacting connectivity management. No information about remote code execution or privilege escalation is provided.

A fix for this issue has been implemented in the Linux kernel mwifiex driver by removing the improper power-save state assignment. Users should update to the Linux kernel version that includes this fix once available. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.