CVE-2024-26897

In the Linux kernel, the following vulnerability has been resolved:

wifi: ath9k: delay all of ath9kwmievent_tasklet() until init is complete

The ath9kwmieventtasklet() used in ath9khtc assumes that all the data structures have been fully initialised by the time it runs. However, because of the order in which things are initialised, this is not guaranteed to be the case, because the device is exposed to the USB subsystem before the ath9k driver initialisation is completed.

We already committed a partial fix for this in commit: 8b3046abc99e ("ath9khtc: fix NULL pointer dereference at ath9khtctxget_packet()")

However, that commit only aborted the WMITXSTATUSEVENTID command in the event tasklet, pairing it with an "initialisation complete" bit in the TX struct. It seems syzbot managed to trigger the race for one of the other commands as well, so let's just move the existing synchronisation bit to cover the whole tasklet (setting it at the end of ath9khtcprobedevice() instead of inside ath9ktx_init()).