On Tue, Jan 7, 2014 at 12:44 PM, William Roberts
<bill.c.roberts(a)gmail.com> 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) {
 --
 1.7.9.5
 
FYI for those wondering. Page 205 and 206, Sections A7.9 and A7.10 in
the K+R C book 2nd edition explicitly states that relational and
equality operators return a 0 or 1.
-- 
Respectfully,
William C Roberts