Re: [PATCH] squash: review-updates

[Eric Paris <eparis@redhat.com>]

On Fri, 2014-01-10 at 16:08 -0500, Eric Paris wrote:
> If you know the buf len, you can just use audit_log_n_untrusted_string()
> I think....

admittedly audit_log_n_untrusted_string() will log ALL of n.  So you
could use strnlen() as the argument to audit_log_n_untrusted_string()
(or create another helper, I don't care)

-Eric
> 
> On Tue, 2014-01-07 at 12:44 -0800, William Roberts wrote:
> > Signed-off-by: William Roberts <wroberts@tresys.com>
> > ---
> >  kernel/auditsc.c |   19 +++++++++++++++----
> >  1 file changed, 15 insertions(+), 4 deletions(-)
> > 
> > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > index a4c2003..9ba1f2a 100644
> > --- a/kernel/auditsc.c
> > +++ b/kernel/auditsc.c
> > @@ -1292,9 +1292,20 @@ static void audit_log_cmdline(struct audit_buffer *ab, struct task_struct *tsk,
> >  		if (!buf)
> >  			goto out;
> >  		res = get_cmdline(tsk, buf, PATH_MAX);
> > -		/* Ensure NULL terminated */
> > -		if (buf[res-1] != '\0')
> > -			buf[res-1] = '\0';
> > +		if (res == 0) {
> > +			kfree(buf);
> > +			goto out;
> > +		}
> > +		/*
> > +		 * Ensure NULL terminated but don't clobber the end
> > +		 * unless the buffer is full. Worst case you end up
> > +		 * with 2 null bytes ending it. By doing it this way
> > +		 * one avoids additional branching. One checking if the
> > +		 * end is null and another to check if their should be
> > +		 * an increment before setting the null byte.
> > +		 */
> > +		res += res < PATH_MAX;
> > +		buf[res-1] = '\0';
> >  		context->cmdline = buf;
> >  	}
> >  	msg = context->cmdline;
> > @@ -1333,8 +1344,8 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
> >  			 context->name_count);
> >  
> >  	audit_log_task_info(ab, tsk);
> > -	audit_log_cmdline(ab, tsk, context);
> >  	audit_log_key(ab, context->filterkey);
> > +	audit_log_cmdline(ab, tsk, context);
> >  	audit_log_end(ab);
> >  
> >  	for (aux = context->aux; aux; aux = aux->next) {
>