On Tue, Feb 12, 2013 at 01:43:28PM +0100, Florian Westphal wrote:
> Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> wrote:
> > On Tue, Feb 12, 2013 at 10:22:38AM +0100, Florian Westphal wrote:
> > > Userspace can cause kernel panic by not specifying orig/reply
> > > tuple: kernel will create a tuple with random stack values.
> > >
> > > Problem is that tuple.dst.dir will be random, too, which
> > > causes nf_ct_tuplehash_to_ctrack() to return garbage.
>
> [..]
>
> > > diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
> > > index 7bbfb3d..e592281 100644
> > > --- a/net/netfilter/nf_conntrack_netlink.c
> > > +++ b/net/netfilter/nf_conntrack_netlink.c
> > > @@ -1596,6 +1596,9 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
> > > if (nlh->nlmsg_flags & NLM_F_CREATE) {
> > > enum ip_conntrack_events events;
> > >
> > > + if (!cda[CTA_TUPLE_ORIG] ||
> > > + !cda[CTA_TUPLE_REPLY])
> > > + return -EINVAL;
> >
> > I think that needs to be && instead of ||.
>
> Uh, maybe I'm too low on caffeine, but when a new conntrack
> is to be created, shouldn't userspace have to specify
> _both_ ORIG and REPLY?
You're right, it's me who is low on caffeine. Sorry.
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