For the few people who have spent the past weeks living under a security rock, the Linux kernel has found itself the subject of multiple severe bugs in the form of Copy Fail and Dirty Frag, both of which allow for privilege escalation. They’ve made many people very upset, and also potentially put many thousands of systems at risk of exploitation. Worse is that system managers are generally left to twiddle their thumbs while waiting for patches to be rolled out. This is where NVIDIA engineer [Sasha Levin] has proposed a ‘kill switch’ for affected kernel functions.
The basic concept seems rather simple, with this feature merely intercepting a call to the affected function and instead returning a predefined return value. This makes it less extreme than hitting a general SCRAM button on the entire kernel, and could theoretically allow the affected systems to keep running until the patched kernel becomes available.
A disadvantage of this is that it obviously modifies the kernel, patching it in-memory so that you need to reboot the system to clear it. Another potential disadvantage is that it opens a potentially massive attack vector, with people in the Cybersecurity sub-Reddit roundly rejecting the idea. Amidst all the other anxious conversions there is also the concern that this particular patch was at least partially generated by an LLM (Claude Opus 4.7) , so one may hope that if it does gets merged into mainline it’ll at least be properly vetted by multiple pairs of well-caffeinated human eyes.