1 files changed, 48 insertions, 0 deletions

diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
index c1351df9f7ee..0f72020bfdcf 100644
--- a/kernel/bpf/bpf_lsm.c
+++ b/kernel/bpf/bpf_lsm.c
@@ -16,6 +16,7 @@
 #include <linux/bpf_local_storage.h>
 #include <linux/btf_ids.h>
 #include <linux/ima.h>
+#include <linux/bpf-cgroup.h>
 
 /* For every LSM hook that allows attachment of BPF programs, declare a nop
  * function where a BPF program can be attached.
@@ -35,6 +36,44 @@ BTF_SET_START(bpf_lsm_hooks)
 #undef LSM_HOOK
 BTF_SET_END(bpf_lsm_hooks)
 
+/* List of LSM hooks that should operate on 'current' cgroup regardless
+ * of function signature.
+ */
+BTF_SET_START(bpf_lsm_current_hooks)
+/* operate on freshly allocated sk without any cgroup association */
+BTF_ID(func, bpf_lsm_sk_alloc_security)
+BTF_ID(func, bpf_lsm_sk_free_security)
+BTF_SET_END(bpf_lsm_current_hooks)
+
+void bpf_lsm_find_cgroup_shim(const struct bpf_prog *prog,
+			     bpf_func_t *bpf_func)
+{
+	const struct btf_param *args;
+
+	if (btf_type_vlen(prog->aux->attach_func_proto) < 1 ||
+	    btf_id_set_contains(&bpf_lsm_current_hooks,
+				prog->aux->attach_btf_id)) {
+		*bpf_func = __cgroup_bpf_run_lsm_current;
+		return;
+	}
+
+	args = btf_params(prog->aux->attach_func_proto);
+
+#ifdef CONFIG_NET
+	if (args[0].type == btf_sock_ids[BTF_SOCK_TYPE_SOCKET])
+		*bpf_func = __cgroup_bpf_run_lsm_socket;
+	else if (args[0].type == btf_sock_ids[BTF_SOCK_TYPE_SOCK])
+		*bpf_func = __cgroup_bpf_run_lsm_sock;
+	else
+#endif
+		*bpf_func = __cgroup_bpf_run_lsm_current;
+}
+
+int bpf_lsm_hook_idx(u32 btf_id)
+{
+	return btf_id_set_index(&bpf_lsm_hooks, btf_id);
+}
+
 int bpf_lsm_verify_prog(struct bpf_verifier_log *vlog,
 			const struct bpf_prog *prog)
 {
@@ -158,6 +197,15 @@ bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return prog->aux->sleepable ? &bpf_ima_file_hash_proto : NULL;
 	case BPF_FUNC_get_attach_cookie:
 		return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto : NULL;
+	case BPF_FUNC_get_local_storage:
+		return prog->expected_attach_type == BPF_LSM_CGROUP ?
+			&bpf_get_local_storage_proto : NULL;
+	case BPF_FUNC_set_retval:
+		return prog->expected_attach_type == BPF_LSM_CGROUP ?
+			&bpf_set_retval_proto : NULL;
+	case BPF_FUNC_get_retval:
+		return prog->expected_attach_type == BPF_LSM_CGROUP ?
+			&bpf_get_retval_proto : NULL;
 	default:
 		return tracing_prog_func_proto(func_id, prog);
 	}