[RFC PATCH ghak32 V2 06/13] audit: add support for non-syscall auxiliary records

Richard Guy Briggs
2018-03-16T09:00:33Z

Standalone audit records have the timestamp and serial number generated
on the fly and as such are unique, making them standalone. This new
function audit_alloc_local() generates a local audit context that will
be used only for a standalone record and its auxiliary record(s). The
context is discarded immediately after the local associated records are
produced.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
---
include/linux/audit.h | 8 ++++++++
kernel/auditsc.c | 20 +++++++++++++++++++-
2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index ed16bb6..c0b83cb 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -227,7 +227,9 @@ static inline int audit_log_container_info(struct audit_context *context,
/* These are defined in auditsc.c */
/* Public API */
extern int audit_alloc(struct task_struct *task);
+extern struct audit_context *audit_alloc_local(void);
extern void __audit_free(struct task_struct *task);
+extern void audit_free_context(struct audit_context *context);
extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1,
unsigned long a2, unsigned long a3);
extern void __audit_syscall_exit(int ret_success, long ret_value);
@@ -472,6 +474,12 @@ static inline int audit_alloc(struct task_struct *task)
{
return 0;
}
+static inline struct audit_context *audit_alloc_local(void)
+{
+ return NULL;
+}
+static inline void audit_free_context(struct audit_context *context)
+{ }
static inline void audit_free(struct task_struct *task)
{ }
static inline void audit_syscall_entry(int major, unsigned long a0,
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 2932ef1..7103d23 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -959,8 +959,26 @@ int audit_alloc(struct task_struct *tsk)
return 0;
}

-static inline void audit_free_context(struct audit_context *context)
+struct audit_context *audit_alloc_local(void)
{
+ struct audit_context *context;
+
+ if (!audit_ever_enabled)
+ return NULL; /* Return if not auditing. */
+
+ context = audit_alloc_context(AUDIT_RECORD_CONTEXT);
+ if (!context)
+ return NULL;
+ context->serial = audit_serial();
+ context->ctime = current_kernel_time64();
+ context->in_syscall = 1;
+ return context;
+}
+
+inline void audit_free_context(struct audit_context *context)
+{
+ if (!context)
+ return;
audit_free_names(context);
unroll_tree_refs(context, NULL, 0);
free_tree_refs(context);
--
1.8.3.1