Linux kernel 7.0-rc removes PREEMPT_NONE, causing a ~49% PostgreSQL throughput regression. The scheduler maintainer refuses to revert the change, demanding PostgreSQL adopt the new RSEQ timeslice extension instead. Ubuntu 26.04 LTS ships with this kernel.
An Anthropic researcher used Claude Code to scan the entire Linux kernel source and unearthed a 23-year-old remotely exploitable heap overflow in NFSv4.0. Technical breakdown plus a reality check on what it costs for ordinary users to replicate this.
