[PATCH v2 1/1] audit_alloc: clear TIF_SYSCALL_AUDIT if !audit_context

[Eric Paris]

On Sun, 2013-09-15 at 19:11 +0200, Oleg Nesterov wrote:
> If audit_filter_task() nacks the new thread it makes sense
> to clear TIF_SYSCALL_AUDIT which can be copied from parent
> by dup_task_struct().
> 
> A wrong TIF_SYSCALL_AUDIT is not really bad but it triggers
> the "slow" audit paths in entry.S to ensure the task can not
> miss audit_syscall_*() calls, this is pointless if the task
> has no ->audit_context.
> 
> Signed-off-by: Oleg Nesterov <oleg at redhat.com>
> Acked-by: Steve Grubb <sgrubb at redhat.com>

Acked-by: Eric Paris <eparis at redhat.com>

Richard, please pick this up into your tree.

> ---
>  kernel/auditsc.c |    4 +++-
>  1 files changed, 3 insertions(+), 1 deletions(-)
> 
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 9845cb3..95293ab 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -943,8 +943,10 @@ int audit_alloc(struct task_struct *tsk)
>  		return 0; /* Return if not auditing. */
>  
>  	state = audit_filter_task(tsk, &key);
> -	if (state == AUDIT_DISABLED)
> +	if (state == AUDIT_DISABLED) {
> +		clear_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
>  		return 0;
> +	}
>  
>  	if (!(context = audit_alloc_context(state))) {
>  		kfree(key);