"Failed to set PTK to the driver"

I want to net boot my machine through WiFi (Intel AC 7260, using iwlwifi driver), and I have created a custom initramfs to do it. However, I have trouble to get it connect to an encrypted network (WPA2 AES(CCMP)) at the early stage of boot (initramfs stage).

I have found wpa_supplicant tries to authenticate with my AP. However, at the association stage, it fails with:

Failed to set PTK to the driver

After some research, I found that I have missed some critical kernel crypto modules, and I believe this is the reason for the failure of connection. Here is the list of modules:

ccm
ctr
lib80211 (I am not sure about this module)

Adding those modules to my /etc/initramfs-tools/modules (as I am creating a custom initramfs) solves my problem.

Hope this helps if you encounter similar issue.