bpf: Add BPF_PROG_TYPE_CGROUP_SKB attach type enforcement in BPF_LINK_CREATE

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Add BPF_PROG_TYPE_CGROUP_SKB attach type enforcement in BPF_LINK_CREATE bpf_prog_attach uses attach_type_to_prog_type to enforce proper attach type for BPF_PROG_TYPE_CGROUP_SKB. link_create uses bpf_prog_get and relies on bpf_prog_attach_check_attach_type to properly verify prog_type <> attach_type association. Add missing attach_type enforcement for the link_create case. Otherwise, it's currently possible to attach cgroup_skb prog types to other cgroup hooks.

References

• https://git.kernel.org/stable/c/6675c541f540a29487a802d3135280b69b9f568d
• https://git.kernel.org/stable/c/67929e973f5a347f05fef064fea4ae79e7cdb5fd
• https://git.kernel.org/stable/c/b34bbc76651065a5eafad8ddff1eb8d1f8473172
• https://git.kernel.org/stable/c/543576ec15b17c0c93301ac8297333c7b6e84ac7