Re: [PATCH ghak90 V6 08/10] audit: add containerid filtering

Paul Moore
2019-05-30T14:34:49Z

On Thu, May 30, 2019 at 10:20 AM Richard Guy Briggs <rgb@redhat.com> wrote:
>
> On 2019-05-29 18:16, Paul Moore wrote:
> > On Mon, Apr 8, 2019 at 11:41 PM Richard Guy Briggs <rgb@redhat.com> wrote:
> > >
> > > Implement audit container identifier filtering using the AUDIT_CONTID
> > > field name to send an 8-character string representing a u64 since the
> > > value field is only u32.
> > >
> > > Sending it as two u32 was considered, but gathering and comparing two
> > > fields was more complex.
> > >
> > > The feature indicator is AUDIT_FEATURE_BITMAP_CONTAINERID.
> > >
> > > Please see the github audit kernel issue for the contid filter feature:
> > > https://github.com/linux-audit/audit-kernel/issues/91
> > > Please see the github audit userspace issue for filter additions:
> > > https://github.com/linux-audit/audit-userspace/issues/40
> > > Please see the github audit testsuiite issue for the test case:
> > > https://github.com/linux-audit/audit-testsuite/issues/64
> > > Please see the github audit wiki for the feature overview:
> > > https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID
> > > Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> > > Acked-by: Serge Hallyn <serge@hallyn.com>
> > > Acked-by: Neil Horman <nhorman@tuxdriver.com>
> > > Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
> > > ---
> > > include/linux/audit.h | 1 +
> > > include/uapi/linux/audit.h | 5 ++++-
> > > kernel/audit.h | 1 +
> > > kernel/auditfilter.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++
> > > kernel/auditsc.c | 4 ++++
> > > 5 files changed, 57 insertions(+), 1 deletion(-)
> >
> > ...
> >
> > > diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> > > index 63f8b3f26fab..407b5bb3b4c6 100644
> > > --- a/kernel/auditfilter.c
> > > +++ b/kernel/auditfilter.c
> > > @@ -1206,6 +1224,31 @@ int audit_comparator(u32 left, u32 op, u32 right)
> > > }
> > > }
> > >
> > > +int audit_comparator64(u64 left, u32 op, u64 right)
> > > +{
> > > + switch (op) {
> > > + case Audit_equal:
> > > + return (left == right);
> > > + case Audit_not_equal:
> > > + return (left != right);
> > > + case Audit_lt:
> > > + return (left < right);
> > > + case Audit_le:
> > > + return (left <= right);
> > > + case Audit_gt:
> > > + return (left > right);
> > > + case Audit_ge:
> > > + return (left >= right);
> > > + case Audit_bitmask:
> > > + return (left & right);
> > > + case Audit_bittest:
> > > + return ((left & right) == right);
> > > + default:
> > > + BUG();
> >
> > A little birdy mentioned the BUG() here as a potential issue and while
> > I had ignored it in earlier patches because this is likely a
> > cut-n-paste from another audit comparator function, I took a closer
> > look this time. It appears as though we will never have an invalid op
> > value as audit_data_to_entry()/audit_to_op() ensure that the op value
> > is a a known good value. Removing the BUG() from all the audit
> > comparators is a separate issue, but I think it would be good to
> > remove it from this newly added comparator; keeping it so that we
> > return "0" in the default case seems reasoanble.
>
> Fair enough. That BUG(); can be removed.

Please send a fixup patch for this.

--
paul moore