security: create task_free security callback
The current LSM interface to cred_free is not sufficient for allowing
an LSM to track the life and death of a task. This patch adds the
task_free hook so that an LSM can clean up resources on task death.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/capability.c b/security/capability.c
index 2f680eb..5bb21b1 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -358,6 +358,10 @@
return 0;
}
+static void cap_task_free(struct task_struct *task)
+{
+}
+
static int cap_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
return 0;
@@ -954,6 +958,7 @@
set_to_cap_if_null(ops, file_receive);
set_to_cap_if_null(ops, dentry_open);
set_to_cap_if_null(ops, task_create);
+ set_to_cap_if_null(ops, task_free);
set_to_cap_if_null(ops, cred_alloc_blank);
set_to_cap_if_null(ops, cred_free);
set_to_cap_if_null(ops, cred_prepare);