On Wed, Jul 16, 2014 at 10:26:48AM +0200, Pablo Neira Ayuso wrote: > From: Florian Westphal <[email protected]> > > [ Upstream commit 945b2b2d259d1a4364a2799e80e8ff32f8c6ee6f ] >
Thank you, I'm queuing the applicable patches to the 3.11 kernel as well. Cheers, -- Luís > Quoting Samu Kallio: > > Basically what's happening is, during netns cleanup, > nf_nat_net_exit gets called before ipv4_net_exit. As I understand > it, nf_nat_net_exit is supposed to kill any conntrack entries which > have NAT context (through nf_ct_iterate_cleanup), but for some > reason this doesn't happen (perhaps something else is still holding > refs to those entries?). > > When ipv4_net_exit is called, conntrack entries (including those > with NAT context) are cleaned up, but the > nat_bysource hashtable is long gone - freed in nf_nat_net_exit. The > bug happens when attempting to free a conntrack entry whose NAT hash > 'prev' field points to a slot in the freed hash table (head for that > bin). > > We ignore conntracks with null nat bindings. But this is wrong, > as these are in bysource hash table as well. > > Restore nat-cleaning for the netns-is-being-removed case. > > bug: > https://bugzilla.kernel.org/show_bug.cgi?id=65191 > > Cc: <[email protected]> # 3.15.x > Cc: <[email protected]> # 3.14.x > Cc: <[email protected]> # 3.12.x > Cc: <[email protected]> # 3.10.x > Fixes: c2d421e1718 ('netfilter: nf_nat: fix race when unloading protocol > modules') > Reported-by: Samu Kallio <[email protected]> > Debugged-by: Samu Kallio <[email protected]> > Signed-off-by: Florian Westphal <[email protected]> > Tested-by: Samu Kallio <[email protected]> > Signed-off-by: Pablo Neira Ayuso <[email protected]> > --- > net/netfilter/nf_nat_core.c | 35 ++++++++++++++++++++++++++++++++++- > 1 file changed, 34 insertions(+), 1 deletion(-) > > diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c > index 09096a6..a49907b 100644 > --- a/net/netfilter/nf_nat_core.c > +++ b/net/netfilter/nf_nat_core.c > @@ -525,6 +525,39 @@ static int nf_nat_proto_remove(struct nf_conn *i, void > *data) > return i->status & IPS_NAT_MASK ? 1 : 0; > } > > +static int nf_nat_proto_clean(struct nf_conn *ct, void *data) > +{ > + struct nf_conn_nat *nat = nfct_nat(ct); > + > + if (nf_nat_proto_remove(ct, data)) > + return 1; > + > + if (!nat || !nat->ct) > + return 0; > + > + /* This netns is being destroyed, and conntrack has nat null binding. > + * Remove it from bysource hash, as the table will be freed soon. > + * > + * Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack() > + * will delete entry from already-freed table. > + */ > + if (!del_timer(&ct->timeout)) > + return 1; > + > + spin_lock_bh(&nf_nat_lock); > + hlist_del_rcu(&nat->bysource); > + ct->status &= ~IPS_NAT_DONE_MASK; > + nat->ct = NULL; > + spin_unlock_bh(&nf_nat_lock); > + > + add_timer(&ct->timeout); > + > + /* don't delete conntrack. Although that would make things a lot > + * simpler, we'd end up flushing all conntracks on nat rmmod. > + */ > + return 0; > +} > + > static void nf_nat_l4proto_clean(u8 l3proto, u8 l4proto) > { > struct nf_nat_proto_clean clean = { > @@ -795,7 +828,7 @@ static void __net_exit nf_nat_net_exit(struct net *net) > { > struct nf_nat_proto_clean clean = {}; > > - nf_ct_iterate_cleanup(net, &nf_nat_proto_remove, &clean, 0, 0); > + nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean, 0, 0); > synchronize_rcu(); > nf_ct_free_hashtable(net->ct.nat_bysource, net->ct.nat_htable_size); > } > -- > 1.7.10.4 > > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
