1 files changed, 93 insertions, 13 deletions

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index ffc6aa6d0f64..2b94d6f02dbb 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -21,6 +21,7 @@
 #include <linux/slab.h>
 #include <linux/idr.h>
 #include <linux/rhashtable.h>
+#include <linux/jhash.h>
 #include <net/net_namespace.h>
 #include <net/sock.h>
 #include <net/netlink.h>
@@ -44,6 +45,62 @@ static LIST_HEAD(tcf_proto_base);
 /* Protects list of registered TC modules. It is pure SMP lock. */
 static DEFINE_RWLOCK(cls_mod_lock);
 
+static u32 destroy_obj_hashfn(const struct tcf_proto *tp)
+{
+	return jhash_3words(tp->chain->index, tp->prio,
+			    (__force __u32)tp->protocol, 0);
+}
+
+static void tcf_proto_signal_destroying(struct tcf_chain *chain,
+					struct tcf_proto *tp)
+{
+	struct tcf_block *block = chain->block;
+
+	mutex_lock(&block->proto_destroy_lock);
+	hash_add_rcu(block->proto_destroy_ht, &tp->destroy_ht_node,
+		     destroy_obj_hashfn(tp));
+	mutex_unlock(&block->proto_destroy_lock);
+}
+
+static bool tcf_proto_cmp(const struct tcf_proto *tp1,
+			  const struct tcf_proto *tp2)
+{
+	return tp1->chain->index == tp2->chain->index &&
+	       tp1->prio == tp2->prio &&
+	       tp1->protocol == tp2->protocol;
+}
+
+static bool tcf_proto_exists_destroying(struct tcf_chain *chain,
+					struct tcf_proto *tp)
+{
+	u32 hash = destroy_obj_hashfn(tp);
+	struct tcf_proto *iter;
+	bool found = false;
+
+	rcu_read_lock();
+	hash_for_each_possible_rcu(chain->block->proto_destroy_ht, iter,
+				   destroy_ht_node, hash) {
+		if (tcf_proto_cmp(tp, iter)) {
+			found = true;
+			break;
+		}
+	}
+	rcu_read_unlock();
+
+	return found;
+}
+
+static void
+tcf_proto_signal_destroyed(struct tcf_chain *chain, struct tcf_proto *tp)
+{
+	struct tcf_block *block = chain->block;
+
+	mutex_lock(&block->proto_destroy_lock);
+	if (hash_hashed(&tp->destroy_ht_node))
+		hash_del_rcu(&tp->destroy_ht_node);
+	mutex_unlock(&block->proto_destroy_lock);
+}
+
 /* Find classifier type by string name */
 
 static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
@@ -231,9 +288,11 @@ static void tcf_proto_get(struct tcf_proto *tp)
 static void tcf_chain_put(struct tcf_chain *chain);
 
 static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
-			      struct netlink_ext_ack *extack)
+			      bool sig_destroy, struct netlink_ext_ack *extack)
 {
 	tp->ops->destroy(tp, rtnl_held, extack);
+	if (sig_destroy)
+		tcf_proto_signal_destroyed(tp->chain, tp);
 	tcf_chain_put(tp->chain);
 	module_put(tp->ops->owner);
 	kfree_rcu(tp, rcu);
@@ -243,7 +302,7 @@ static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
 			  struct netlink_ext_ack *extack)
 {
 	if (refcount_dec_and_test(&tp->refcnt))
-		tcf_proto_destroy(tp, rtnl_held, extack);
+		tcf_proto_destroy(tp, rtnl_held, true, extack);
 }
 
 static int walker_check_empty(struct tcf_proto *tp, void *fh,
@@ -367,6 +426,7 @@ static bool tcf_chain_detach(struct tcf_chain *chain)
 static void tcf_block_destroy(struct tcf_block *block)
 {
 	mutex_destroy(&block->lock);
+	mutex_destroy(&block->proto_destroy_lock);
 	kfree_rcu(block, rcu);
 }
 
@@ -542,6 +602,12 @@ static void tcf_chain_flush(struct tcf_chain *chain, bool rtnl_held)
 
 	mutex_lock(&chain->filter_chain_lock);
 	tp = tcf_chain_dereference(chain->filter_chain, chain);
+	while (tp) {
+		tp_next = rcu_dereference_protected(tp->next, 1);
+		tcf_proto_signal_destroying(chain, tp);
+		tp = tp_next;
+	}
+	tp = tcf_chain_dereference(chain->filter_chain, chain);
 	RCU_INIT_POINTER(chain->filter_chain, NULL);
 	tcf_chain0_head_change(chain, NULL);
 	chain->flushing = true;
@@ -979,6 +1045,7 @@ static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
 		return ERR_PTR(-ENOMEM);
 	}
 	mutex_init(&block->lock);
+	mutex_init(&block->proto_destroy_lock);
 	INIT_LIST_HEAD(&block->chain_list);
 	INIT_LIST_HEAD(&block->cb_list);
 	INIT_LIST_HEAD(&block->owner_list);
@@ -1660,7 +1727,7 @@ int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 reclassify:
 #endif
 	for (; tp; tp = rcu_dereference_bh(tp->next)) {
-		__be16 protocol = tc_skb_protocol(skb);
+		__be16 protocol = skb_protocol(skb, false);
 		int err;
 
 		if (tp->protocol != protocol &&
@@ -1758,6 +1825,12 @@ static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
 
 	mutex_lock(&chain->filter_chain_lock);
 
+	if (tcf_proto_exists_destroying(chain, tp_new)) {
+		mutex_unlock(&chain->filter_chain_lock);
+		tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
+		return ERR_PTR(-EAGAIN);
+	}
+
 	tp = tcf_chain_tp_find(chain, &chain_info,
 			       protocol, prio, false);
 	if (!tp)
@@ -1765,10 +1838,10 @@ static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
 	mutex_unlock(&chain->filter_chain_lock);
 
 	if (tp) {
-		tcf_proto_destroy(tp_new, rtnl_held, NULL);
+		tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
 		tp_new = tp;
 	} else if (err) {
-		tcf_proto_destroy(tp_new, rtnl_held, NULL);
+		tcf_proto_destroy(tp_new, rtnl_held, false, NULL);
 		tp_new = ERR_PTR(err);
 	}
 
@@ -1806,6 +1879,7 @@ static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
 		return;
 	}
 
+	tcf_proto_signal_destroying(chain, tp);
 	next = tcf_chain_dereference(chain_info.next, chain);
 	if (tp == chain->filter_chain)
 		tcf_chain0_head_change(chain, next);
@@ -2075,6 +2149,7 @@ replay:
 		err = PTR_ERR(block);
 		goto errout;
 	}
+	block->classid = parent;
 
 	chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
 	if (chain_index > TC_ACT_EXT_VAL_MASK) {
@@ -2125,9 +2200,8 @@ replay:
 							       &chain_info));
 
 		mutex_unlock(&chain->filter_chain_lock);
-		tp_new = tcf_proto_create(nla_data(tca[TCA_KIND]),
-					  protocol, prio, chain, rtnl_held,
-					  extack);
+		tp_new = tcf_proto_create(name, protocol, prio, chain,
+					  rtnl_held, extack);
 		if (IS_ERR(tp_new)) {
 			err = PTR_ERR(tp_new);
 			goto errout_tp;
@@ -2325,6 +2399,7 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		err = -EINVAL;
 		goto errout_locked;
 	} else if (t->tcm_handle == 0) {
+		tcf_proto_signal_destroying(chain, tp);
 		tcf_chain_tp_remove(chain, &chain_info, tp);
 		mutex_unlock(&chain->filter_chain_lock);
 
@@ -2617,12 +2692,10 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 			return skb->len;
 
 		parent = tcm->tcm_parent;
-		if (!parent) {
+		if (!parent)
 			q = dev->qdisc;
-			parent = q->handle;
-		} else {
+		else
 			q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
-		}
 		if (!q)
 			goto out;
 		cops = q->ops->cl_ops;
@@ -2638,6 +2711,7 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 		block = cops->tcf_block(q, cl, NULL);
 		if (!block)
 			goto out;
+		parent = block->classid;
 		if (tcf_block_shared(block))
 			q = NULL;
 	}
@@ -2783,13 +2857,19 @@ static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
 			      struct netlink_ext_ack *extack)
 {
 	const struct tcf_proto_ops *ops;
+	char name[IFNAMSIZ];
 	void *tmplt_priv;
 
 	/* If kind is not set, user did not specify template. */
 	if (!tca[TCA_KIND])
 		return 0;
 
-	ops = tcf_proto_lookup_ops(nla_data(tca[TCA_KIND]), true, extack);
+	if (tcf_proto_check_kind(tca[TCA_KIND], name)) {
+		NL_SET_ERR_MSG(extack, "Specified TC chain template name too long");
+		return -EINVAL;
+	}
+
+	ops = tcf_proto_lookup_ops(name, true, extack);
 	if (IS_ERR(ops))
 		return PTR_ERR(ops);
 	if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {