Re: [PATCH ghak59 V3 2/4] audit: add syscall information to CONFIG_CHANGE records

[Richard Guy Briggs]

On 2019-01-14 17:58, Paul Moore wrote:
> On Mon, Dec 10, 2018 at 5:18 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> > Tie syscall information to all CONFIG_CHANGE calls since they are all a
> > result of user actions.
> >
> > Exclude user records from syscall context:
> > Since the function audit_log_common_recv_msg() is shared by a number of
> > AUDIT_CONFIG_CHANGE and the entire range of AUDIT_USER_* record types,
> > and since the AUDIT_CONFIG_CHANGE message type has been converted to a
> > syscall accompanied record type, special-case the AUDIT_USER_* range of
> > messages so they remain standalone records.
> >
> > See: https://github.com/linux-audit/audit-kernel/issues/59
> > See: https://github.com/linux-audit/audit-kernel/issues/50
> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> > ---
> >  kernel/audit.c          | 27 +++++++++++++++++++--------
> >  kernel/audit_fsnotify.c |  2 +-
> >  kernel/audit_tree.c     |  2 +-
> >  kernel/audit_watch.c    |  2 +-
> >  kernel/auditfilter.c    |  2 +-
> >  5 files changed, 23 insertions(+), 12 deletions(-)
> >
> > diff --git a/kernel/audit.c b/kernel/audit.c
> > index 0e8026423fbd..a321fea94cc6 100644
> > --- a/kernel/audit.c
> > +++ b/kernel/audit.c
> > @@ -1072,6 +1073,16 @@ static void audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
> >         audit_log_task_context(*ab);
> >  }
> >
> > +static inline void audit_log_user_recv_msg(struct audit_buffer **ab, u16 msg_type)
> > +{
> > +       audit_log_common_recv_msg(NULL, ab, msg_type);
> > +}
> 
> This makes sense because this is used by "user" records ...
> 
> > +static inline void audit_log_config_change_alt(struct audit_buffer **ab)
> > +{
> > +       audit_log_common_recv_msg(audit_context(), ab, AUDIT_CONFIG_CHANGE);
> > +}
> 
> ... and I don't believe this makes sense because there is no real
> logical grouping with the callers like there is for
> audit_log_user_recv_msg().

I don't follow "logical grouping".  They are all CONFIG_CHANGE record
prefixes with the current context.

Can you suggest an alternate name or another way of sharing
audit_log_common_recv_msg() since the only differences between the two
are a NULL context vs current task's context and the message type.  I
wasn't particularly happy with this name either.  I'd really like to
refactor this with all the rest of the CONFIG_CHANGE records, but there
is too much of a format difference to make it work without reordering or
deleting useless fields.

I know you had suggested making two different functions, but I think
they are more similar than different and merit the common factored code.

> paul moore

- RGB

--
Richard Guy Briggs <rgb@xxxxxxxxxx>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635