Infrastructure management of the cred security blob

Move management of the cred security blob out of the
security modules and into the security infrastructre.
Instead of allocating and freeing space the security
modules tell the infrastructure how much space they
require.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[kees: adjusted for ordered init series]
Signed-off-by: Kees Cook <keescook@chromium.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 8c2cb4b1a6c3..d5e4a384f205 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1151,6 +1151,13 @@ static int apparmor_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 }
 #endif
 
+/*
+ * The cred blob is a pointer to, not an instance of, an aa_task_ctx.
+ */
+struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
+	.lbs_cred = sizeof(struct aa_task_ctx *),
+};
+
 static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
 	LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
@@ -1485,6 +1492,7 @@ static int __init set_init_ctx(void)
 	if (!ctx)
 		return -ENOMEM;
 
+	lsm_early_cred(cred);
 	set_cred_label(cred, aa_get_label(ns_unconfined(root_ns)));
 	task_ctx(current) = ctx;
 
@@ -1725,5 +1733,6 @@ DEFINE_LSM(apparmor) = {
 	.name = "apparmor",
 	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
 	.enabled = &apparmor_enabled,
+	.blobs = &apparmor_blob_sizes,
 	.init = apparmor_init,
 };