I think your right....
On Fri, Jan 10, 2014 at 1:08 PM, Eric Paris <eparis(a)redhat.com> wrote:
 If you know the buf len, you can just use
audit_log_n_untrusted_string()
 I think....
 On Tue, 2014-01-07 at 12:44 -0800, William Roberts wrote:
> Signed-off-by: William Roberts <wroberts(a)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) {
 
-- 
Respectfully,
William C Roberts