bpf: Add BPF_PROG_TYPE_CGROUP_SKB attach type enforcement in BPF_LINK_CREATE

jira LE-2177
cve CVE-2024-38564
Rebuild_History Non-Buildable kernel-5.14.0-503.19.1.el9_5
commit-author Stanislav Fomichev <[email protected]>
commit 543576e

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.

Fixes: af6eea5 ("bpf: Implement bpf_link-based cgroup BPF program attachment")
Link: https://lore.kernel.org/bpf/[email protected]/
	Reported-by: [email protected]
	Signed-off-by: Stanislav Fomichev <[email protected]>
	Acked-by: Eduard Zingerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
	Signed-off-by: Martin KaFai Lau <[email protected]>
(cherry picked from commit 543576e)
	Signed-off-by: Jonathan Maple <[email protected]>

Author: PlaidCat

kernel/bpf/syscall.c

@@ -3828,6 +3828,11 @@ static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
 			 * check permissions at attach time.
 			 */
 			return -EPERM;
+
+		ptype = attach_type_to_prog_type(attach_type);
+		if (prog->type != ptype)
+			return -EINVAL;
+
 		return prog->enforce_expected_attach_type &&
 			prog->expected_attach_type != attach_type ?
 			-EINVAL : 0;