CVE-2026-64548 bpf, sockmap: reject overflowing copy + len in bpf_msg_push_data()

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: reject overflowing copy + len in bpfmsgpushdata When the scatterlist ring is full or nearly full, bpfmsgpushdata enters a copy fallback path and computes copy + len for the page allocation size. Since len comes from...