CVE-2026-90157 bpf: Reject negative optlen in cgroup getsockopt hook

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject negative optlen in cgroup getsockopt hook A cgroup getsockopt BPF program can shrink ctx-optlen after the kernel getsockopt handler has run. The kernel-buffer variant, used by TCPZEROCOPYRECEIVE, only rejects values...