diff mbox series

[v2] netfilter: ipset: Fix calling ip_set() macro at dumping

Message ID 1540935822-10510-1-git-send-email-kadlec@blackhole.kfki.hu
State Accepted
Delegated to: Pablo Neira
Headers show
Series [v2] netfilter: ipset: Fix calling ip_set() macro at dumping | expand

Commit Message

Jozsef Kadlecsik Oct. 30, 2018, 9:43 p.m. UTC
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>
---
 net/netfilter/ipset/ip_set_core.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

Comments

Pablo Neira Ayuso Nov. 3, 2018, 11:58 a.m. UTC | #1
On Tue, Oct 30, 2018 at 10:43:42PM +0100, Jozsef Kadlecsik wrote:
> 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.

Applied, thanks Jozsef.
diff mbox series

Patch

diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index 68db946..1577f2f 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -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 @@  ip_set_dump_start(struct sk_buff *skb, struct netlink_callback *cb)
 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);