Re: [PATCH v1 4/8] LSM: Maintain a table of LSM attribute data

Paul Moore
2022-11-09T23:34:46Z

On Thu, Oct 27, 2022 at 1:14 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> On Thu, Oct 27, 2022 at 10:08:23AM -0700, Casey Schaufler wrote:
> > On 10/26/2022 11:29 PM, Greg KH wrote:
> > > On Wed, Oct 26, 2022 at 05:38:21PM -0700, Casey Schaufler wrote:
> > >> On 10/25/2022 11:00 PM, Greg KH wrote:
> > >>> On Tue, Oct 25, 2022 at 11:45:15AM -0700, Casey Schaufler wrote:
> > >>>> As LSMs are registered add their lsm_id pointers to a table.
> > >>>> This will be used later for attribute reporting.
> > >>>>
> > >>>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> > >>>> ---
> > >>>> include/linux/security.h | 17 +++++++++++++++++
> > >>>> security/security.c | 18 ++++++++++++++++++
> > >>>> 2 files changed, 35 insertions(+)
> > >>>>
> > >>>> diff --git a/include/linux/security.h b/include/linux/security.h
> > >>>> index ca1b7109c0db..e1678594d983 100644
> > >>>> --- a/include/linux/security.h
> > >>>> +++ b/include/linux/security.h
> > >>>> @@ -138,6 +138,23 @@ enum lockdown_reason {
> > >>>>
> > >>>> extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1];
> > >>>>
> > >>>> +#define LSMID_ENTRIES ( \
> > >>>> + 1 + /* capabilities */ \
> > >>> No #define for capabilities?
> > >> Nope. There isn't one. CONFIG_SECURITY takes care of it.
> > >>
> > >>>> + (IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \
> > >>>> + (IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \
> > >>>> + (IS_ENABLED(CONFIG_SECURITY_TOMOYO) ? 1 : 0) + \
> > >>>> + (IS_ENABLED(CONFIG_SECURITY_IMA) ? 1 : 0) + \
> > >>>> + (IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0) + \
> > >>>> + (IS_ENABLED(CONFIG_SECURITY_YAMA) ? 1 : 0) + \
> > >>>> + (IS_ENABLED(CONFIG_SECURITY_LOADPIN) ? 1 : 0) + \
> > >>>> + (IS_ENABLED(CONFIG_SECURITY_SAFESETID) ? 1 : 0) + \
> > >>>> + (IS_ENABLED(CONFIG_SECURITY_LOCKDOWN) ? 1 : 0) + \
> > >>>> + (IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0) + \
> > >>>> + (IS_ENABLED(CONFIG_SECURITY_LANDLOCK) ? 1 : 0))
> > >>>> +
> > >>>> +extern int lsm_id;
> > >>> u64?
> > >> u32. I doubt we'll get more than 32K security modules.
> > > These should be bits, not values, right?
> >
> > lsm_id is the count of security modules that are registered.
> > It seemed like a good name for the value at the time, but as
> > it's causing confusion I should probably change it.
>
> Yeah, that's confusing. "lsm_num_availble" might be better.

Yes, this really should be named something else. I'm partial to
"lsm_count" as it is shorter than the other suggestion, but this is
hardly something to worry too much about.

--
paul-moore.com