Re: [RFC] [PATCH] audit: log module name on init_module

[Paul Moore]

On Tue, Jan 31, 2017 at 3:02 PM, Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> On 2017-01-31 11:07, Paul Moore wrote:
>> On Tue, Jan 31, 2017 at 7:36 AM, Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
>> > On 2017-01-31 06:59, Paul Moore wrote:
>> >> On Thu, Jan 26, 2017 at 4:21 PM, Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
>> >> > This adds a new auxiliary record MODULE_INIT to the SYSCALL event.
>> >> >
>> >> > We get finit_module for free since it made most sense to hook this in to
>> >> > load_module().
>> >> >
>> >> > https://github.com/linux-audit/audit-kernel/issues/7
>> >> > https://github.com/linux-audit/audit-kernel/wiki/RFE-Module-load-record-format
>> >>
>> >> Consistency nit: capitalize the first letter in the wiki page words
>> >> (see the existing RFE pages)
>> >>
>> >> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
>> >> > ---
>> >> >  include/linux/audit.h      |   12 ++++++++++++
>> >> >  include/uapi/linux/audit.h |    1 +
>> >> >  kernel/audit.h             |    3 +++
>> >> >  kernel/auditsc.c           |   20 ++++++++++++++++++++
>> >> >  kernel/module.c            |    5 ++++-
>> >> >  5 files changed, 40 insertions(+), 1 deletions(-)
>> >> >
>> >> > diff --git a/include/linux/audit.h b/include/linux/audit.h
>> >> > index 2be99b2..7bb23d5 100644
>> >> > --- a/include/linux/audit.h
>> >> > +++ b/include/linux/audit.h
>> >> > @@ -360,6 +360,7 @@ extern int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
>> >> >                                   const struct cred *old);
>> >> >  extern void __audit_log_capset(const struct cred *new, const struct cred *old);
>> >> >  extern void __audit_mmap_fd(int fd, int flags);
>> >> > +extern void __audit_module_init(char *name);
>> >> >
>> >> >  static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)
>> >> >  {
>> >> > @@ -450,6 +451,12 @@ static inline void audit_mmap_fd(int fd, int flags)
>> >> >                 __audit_mmap_fd(fd, flags);
>> >> >  }
>> >> >
>> >> > +static inline void audit_module_init(char *name)
>> >> > +{
>> >> > +       if (!audit_dummy_context())
>> >> > +               __audit_module_init(name);
>> >> > +}
>> >>
>> >> More on this below, but I was expecting the function above to named
>> >> audit_log_kern_module(), or something similar.
>> >
>> > Ok fair enough, I had mis-understood your previous point.
>>
>> I probably could have been more specific too.
>>
>> > Any comment on the new record format?
>>
>> Not really, it's just the single field so it's kinda hard to have
>> anything meaningful to say.  We obviously need to worry about the
>> field name, but I'll let Steve speak to that as that likely means more
>> to him than it does to me.  From my perspective, "name" seems
>> perfectly reasonable, especially since it is in the context of a
>> module specific record (no real worries about it being ambiguous).
>
> Do you see a need to include module initialization arguments?  It sounds
> potentially useful to me, but also potentially bandwidth-consuming.  I
> have a prototype patch to add the args as one encoded field.  Along with
> the addition of this field is the concern about message lengths and
> buffer allocations since it is an encoded field that would need twice
> the length of the argment text to store in the message.

Argument filtering is surely going to be a mess, just look at the
related execve() stuff.  Unless there is a hard requirement I say skip
the argument logging for now, we can always add it later.

-- 
paul moore
www.paul-moore.com