netfilter: ipset: Fix calling ip_set() macro at dumping

The ip_set() macro is called when either ip_set_ref_lock held only
or no lock/nfnl mutex is held at dumping. Take this into account
properly. Also, use Pablo's suggestion to use rcu_dereference_raw(),
the ref_netlink protects the set.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Jozsef Kadlecsik 2018-10-30 22:43:42 +01:00 committed by Pablo Neira Ayuso
parent 54451f60c8
commit 8a02bdd50b

View File

@ -55,11 +55,15 @@ MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
MODULE_DESCRIPTION("core IP set support");
MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_IPSET);
/* When the nfnl mutex is held: */
/* When the nfnl mutex or ip_set_ref_lock is held: */
#define ip_set_dereference(p) \
rcu_dereference_protected(p, lockdep_nfnl_is_held(NFNL_SUBSYS_IPSET))
rcu_dereference_protected(p, \
lockdep_nfnl_is_held(NFNL_SUBSYS_IPSET) || \
lockdep_is_held(&ip_set_ref_lock))
#define ip_set(inst, id) \
ip_set_dereference((inst)->ip_set_list)[id]
#define ip_set_ref_netlink(inst,id) \
rcu_dereference_raw((inst)->ip_set_list)[id]
/* The set types are implemented in modules and registered set types
* can be found in ip_set_type_list. Adding/deleting types is
@ -1251,7 +1255,7 @@ ip_set_dump_done(struct netlink_callback *cb)
struct ip_set_net *inst =
(struct ip_set_net *)cb->args[IPSET_CB_NET];
ip_set_id_t index = (ip_set_id_t)cb->args[IPSET_CB_INDEX];
struct ip_set *set = ip_set(inst, index);
struct ip_set *set = ip_set_ref_netlink(inst, index);
if (set->variant->uref)
set->variant->uref(set, cb, false);
@ -1440,7 +1444,7 @@ next_set:
release_refcount:
/* If there was an error or set is done, release set */
if (ret || !cb->args[IPSET_CB_ARG0]) {
set = ip_set(inst, index);
set = ip_set_ref_netlink(inst, index);
if (set->variant->uref)
set->variant->uref(set, cb, false);
pr_debug("release set %s\n", set->name);