bpf,lsm: Add BPF token LSM hooks

Wire up bpf_token_create and bpf_token_free LSM hooks, which allow to
allocate LSM security blob (we add `void *security` field to struct
bpf_token for that), but also control who can instantiate BPF token.
This follows existing pattern for BPF map and BPF prog.

Also add security_bpf_token_allow_cmd() and security_bpf_token_capable()
LSM hooks that allow LSM implementation to control and negate (if
necessary) BPF token's delegation of a specific bpf_cmd and capability,
respectively.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-12-andrii@kernel.org

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 4e146e9708be..b86bd15a051d 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1634,6 +1634,9 @@ struct bpf_token {
 	u64 allowed_maps;
 	u64 allowed_progs;
 	u64 allowed_attachs;
+#ifdef CONFIG_SECURITY
+	void *security;
+#endif
 };
 
 struct bpf_struct_ops_value;