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

[Richard Guy Briggs]

On 2017-02-03 19:18, Paul Moore wrote:
> 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.

I *did* look at execve, which is why I was apprehensive.  :-/

> paul moore

- RGB

--
Richard Guy Briggs <rgb@xxxxxxxxxx>
Kernel Security Engineering, Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635