Re: [PATCH nf] netfilter: nf_tables: fix addition/deletion of elements from commit/abort

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Sat, Feb 21, 2015 at 10:39:18AM +0000, Patrick McHardy wrote:
> On 20.02, Pablo Neira Ayuso wrote:
> > We have several problems in this path:
> > 
> > 1) There is a use-after-free when removing individual elements from
> >    the commit path.
> > 
> > 2) We have to uninit() the data part of the element from the abort
> >    path to avoid a chain refcount leak.
> > 
> > 3) We have to check for set->flags to see if there's a mapping, instead
> >    of the element flags.
> > 
> > 4) We have to check for !(flags & NFT_SET_ELEM_INTERVAL_END) to skip
> >    elements that are part of the interval that have no data part, so
> >    they don't need to be uninit().
> 
> Just wondering, in the delete case, don't we need to set the flags in
> the sets' ->get() function for this to work?

They are already set from hash and rbtree, so we only need to add the
check for NFT_SET_ELEM_INTERVAL_END from the commit path in nf_tables_api.c

Unless you have any further concern, I'll pass up this soon.