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

From: Richard Guy Briggs
Date: Mon Sep 23 2013 - 17:55:27 EST


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@xxxxxxxxxx>
> > Acked-by: Steve Grubb <sgrubb@xxxxxxxxxx>
>
> Acked-by: Eric Paris <eparis@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
Senior Software Engineer
Kernel Security
AMER ENG Base Operating Systems
Remote, Ottawa, Canada
Voice: +1.647.777.2635
Internal: (81) 32635
Alt: +1.613.693.0684x3545
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/