CVE-2026-68399 bpf: Fix UAF in sock clone early bailouts

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix UAF in sock clone early bailouts Similar to recent commit 9b51a6155d14 "bpf,fork: wipe -bpfstorage before bailouts that access it", skclone performs an initial shallow copy of the socket field -skbpfstorage via sockcopy...