[PATCH bpf-next 17/29] bpf,selinux: allocate bpf_security_struct per BPF token

Andrii Nakryiko
2024-01-03T22:23:41Z

Utilize newly added bpf_token_create/bpf_token_free LSM hooks to
allocate struct bpf_security_struct for each BPF token object in
SELinux. This just follows similar pattern for BPF prog and map.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
security/selinux/hooks.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index c4ba3f0fcb97..30d8078b1ca1 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6822,6 +6822,29 @@ static void selinux_bpf_prog_free(struct bpf_prog *prog)
prog->aux->security = NULL;
kfree(bpfsec);
}
+
+static int selinux_bpf_token_create(struct bpf_token *token, union bpf_attr *attr,
+ struct path *path)
+{
+ struct bpf_security_struct *bpfsec;
+
+ bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
+ if (!bpfsec)
+ return -ENOMEM;
+
+ bpfsec->sid = current_sid();
+ token->security = bpfsec;
+
+ return 0;
+}
+
+static void selinux_bpf_token_free(struct bpf_token *token)
+{
+ struct bpf_security_struct *bpfsec = token->security;
+
+ token->security = NULL;
+ kfree(bpfsec);
+}
#endif

struct lsm_blob_sizes selinux_blob_sizes __ro_after_init = {
@@ -7177,6 +7200,7 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = {
LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog),
LSM_HOOK_INIT(bpf_map_free, selinux_bpf_map_free),
LSM_HOOK_INIT(bpf_prog_free, selinux_bpf_prog_free),
+ LSM_HOOK_INIT(bpf_token_free, selinux_bpf_token_free),
#endif

#ifdef CONFIG_PERF_EVENTS
@@ -7235,6 +7259,7 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = {
#ifdef CONFIG_BPF_SYSCALL
LSM_HOOK_INIT(bpf_map_create, selinux_bpf_map_create),
LSM_HOOK_INIT(bpf_prog_load, selinux_bpf_prog_load),
+ LSM_HOOK_INIT(bpf_token_create, selinux_bpf_token_create),
#endif
#ifdef CONFIG_PERF_EVENTS
LSM_HOOK_INIT(perf_event_alloc, selinux_perf_event_alloc),
--
2.34.1