CVE-2021-3489 Linux kernel eBPF RINGBUF map oversized allocation

The eBPF RINGBUF bpfringbufreserve function in the Linux kernel did not check that the allocated size was smaller than the ringbuf size, allowing an attacker to perform out-of-bounds writes within the kernel and therefore, arbitrary code execution. This issue was fixed via commit 4b81ccebaeee "bp...