Lenovo T450 Wireless AC 7265 not working on Linux

Lately I discovered an issue with my WiFi adapter on my professional laptop (a Lenovo T450) : it was not working. Pretty inconvenient. After some digging, I tested and had to adapt part of things I found on Google. So, to begging with, the symptoms :

• no more wireless adapter in my NetworkManager or any other tools, including ifconfig
• dmesg reports issues loading the iwlwifi firmware<

The dmesg output looks like :

I tried to download the official firmware from Intel, namely iwlwifi-7265-ucode-25.30.14.0, with no luck. Though, I decided to keep the ucode files from this archive in my /lib/firmware/. Note that, depending on your distro, this previous step might be enough. To check :

Then, further dig pointed some issues with the iwlwifi package not handling properly this version of the AC 7265. From lspci :

Here, the main points are the main ID 095b and the Subsystem ID 5210. To solve this, let's recompile the backport package of iwlwifi with a tiny difference (the sed line is to adapt with your IDs) :

Now, if you check your dmesg, you'll see :

And, voilà, your wireless adapter is back online !* **NB**: you'll have to redo these steps after every kernel update, except if the iwlwifi module got fixed.