I have done some similar work.

First, when Claude refuses I sometimes continue with Kimi or DeepSeek. They are less squeamish. Alas, the combination of C + kernel reliably makes Claude freak out: because of all the UB any tiny error becomes a security hole. (I have the cybersecurity verification stuff from OpenAI and Anthropic but they are still fairly strict.)

Second, contributing directly to the Linux kernel has never been easier. Claude knows all about how to interact with the archaic kernel mailing lists. The main rule I suggest: put in real effort, don't dump AI slop.

However I mostly worked in fixing filesystem bugs so far. I don't know whether the networking and DMA folks are as nice. But probably yes.

(Coincidence: the isofs filesystem code in the kernel is full of tiny holes as far as I can tell. I've patched some of them, but better don't try to mount a malicious CD image.)