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

Paul Moore
2018-04-19T00:39:12Z

On Fri, Mar 16, 2018 at 5:00 AM, Richard Guy Briggs <rgb@redhat.com> wrote:
> 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);

I'm reserving the option to comment on this idea further as I make my
way through the patchset, but audit_free_context() definitely
shouldn't be declared as an inline function.

--
paul moore