Re: [PATCH 4/5] Make LSM Writable Hooks a command line option

From: Tetsuo Handa
Date: Mon Jun 05 2017 - 16:50:27 EST


Casey Schaufler wrote:
> > @@ -33,8 +34,17 @@
> > /* Maximum number of letters for an LSM name string */
> > #define SECURITY_NAME_MAX 10
> >
> > -static struct list_head hook_heads[LSM_MAX_HOOK_INDEX]
> > - __lsm_ro_after_init;
> > +static int security_debug;
> > +
> > +static __init int set_security_debug(char *str)
> > +{
> > + get_option(&str, &security_debug);
> > + return 0;
> > +}
> > +early_param("security_debug", set_security_debug);
>
> I don't care for calling this "security debug". Making
> the lists writable after init isn't about development,
> it's about (Tetsuo's desire for) dynamic module loading.
> I would prefer "dynamic_module_lists" our something else
> more descriptive.

Maybe dynamic_lsm ?

>
> > +
> > +static struct list_head *hook_heads;
> > +static struct pmalloc_pool *sec_pool;
> > char *lsm_names;
> > /* Boot-time LSM user choice */
> > static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
> > @@ -59,6 +69,13 @@ int __init security_init(void)
> > {
> > enum security_hook_index i;
> >
> > + sec_pool = pmalloc_create_pool("security");
> > + if (!sec_pool)
> > + goto error_pool;
>
> Excessive gotoing - return -ENOMEM instead.

But does it make sense to continue?
hook_heads == NULL and we will oops as soon as
call_void_hook() or call_int_hook() is called for the first time.