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

[Richard Guy Briggs]

On Fri, Sep 20, 2013 at 12:08:02PM -0400, Eric Paris wrote:
> 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.

Ack.

> > ---
> >  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);

- RGB

--
Richard Guy Briggs <rbriggs at redhat.com>
Senior Software Engineer
Kernel Security
AMER ENG Base Operating Systems
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