[PATCH 6.0 259/862] bpf: Only add BTF IDs for socket security hooks when CONFIG_SECURITY_NETWORK is on

From: Greg Kroah-Hartman
Date: Wed Oct 19 2022 - 04:55:46 EST


From: Hou Tao <houtao1@xxxxxxxxxx>

[ Upstream commit ef331a8d4c0061ea4d353cd0db1c9b33fd45f0f2 ]

When CONFIG_SECURITY_NETWORK is disabled, there will be build warnings
from resolve_btfids:

WARN: resolve_btfids: unresolved symbol bpf_lsm_socket_socketpair
......
WARN: resolve_btfids: unresolved symbol bpf_lsm_inet_conn_established

Fixing it by wrapping these BTF ID definitions by CONFIG_SECURITY_NETWORK.

Fixes: 69fd337a975c ("bpf: per-cgroup lsm flavor")
Fixes: 9113d7e48e91 ("bpf: expose bpf_{g,s}etsockopt to lsm cgroup")
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220901065126.3856297-1-houtao@xxxxxxxxxxxxxxx
Signed-off-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
kernel/bpf/bpf_lsm.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
index fa71d58b7ded..832a0e48a2a1 100644
--- a/kernel/bpf/bpf_lsm.c
+++ b/kernel/bpf/bpf_lsm.c
@@ -41,17 +41,21 @@ BTF_SET_END(bpf_lsm_hooks)
*/
BTF_SET_START(bpf_lsm_current_hooks)
/* operate on freshly allocated sk without any cgroup association */
+#ifdef CONFIG_SECURITY_NETWORK
BTF_ID(func, bpf_lsm_sk_alloc_security)
BTF_ID(func, bpf_lsm_sk_free_security)
+#endif
BTF_SET_END(bpf_lsm_current_hooks)

/* List of LSM hooks that trigger while the socket is properly locked.
*/
BTF_SET_START(bpf_lsm_locked_sockopt_hooks)
+#ifdef CONFIG_SECURITY_NETWORK
BTF_ID(func, bpf_lsm_socket_sock_rcv_skb)
BTF_ID(func, bpf_lsm_sock_graft)
BTF_ID(func, bpf_lsm_inet_csk_clone)
BTF_ID(func, bpf_lsm_inet_conn_established)
+#endif
BTF_SET_END(bpf_lsm_locked_sockopt_hooks)

/* List of LSM hooks that trigger while the socket is _not_ locked,
@@ -59,8 +63,10 @@ BTF_SET_END(bpf_lsm_locked_sockopt_hooks)
* in the early init phase.
*/
BTF_SET_START(bpf_lsm_unlocked_sockopt_hooks)
+#ifdef CONFIG_SECURITY_NETWORK
BTF_ID(func, bpf_lsm_socket_post_create)
BTF_ID(func, bpf_lsm_socket_socketpair)
+#endif
BTF_SET_END(bpf_lsm_unlocked_sockopt_hooks)

#ifdef CONFIG_CGROUP_BPF
--
2.35.1