Merge branch 'net-sched-use-after-free'

Cong Wang says:

====================
net_sched: fix a use-after-free for tc actions

This patchset fixes a use-after-free reported by Lucas
and closes potential races too.

Please see each patch for details.
====================

Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/act_api.h b/include/net/act_api.h
index b944e0e..c685512 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -13,6 +13,7 @@
 struct tcf_idrinfo {
 	spinlock_t	lock;
 	struct idr	action_idr;
+	struct net	*net;
 };
 
 struct tc_action_ops;
@@ -104,7 +105,7 @@
 
 static inline
 int tc_action_net_init(struct tc_action_net *tn,
-		       const struct tc_action_ops *ops)
+		       const struct tc_action_ops *ops, struct net *net)
 {
 	int err = 0;
 
@@ -112,6 +113,7 @@
 	if (!tn->idrinfo)
 		return -ENOMEM;
 	tn->ops = ops;
+	tn->idrinfo->net = net;
 	spin_lock_init(&tn->idrinfo->lock);
 	idr_init(&tn->idrinfo->action_idr);
 	return err;
@@ -122,7 +124,9 @@
 
 static inline void tc_action_net_exit(struct tc_action_net *tn)
 {
+	rtnl_lock();
 	tcf_idrinfo_destroy(tn->ops, tn->idrinfo);
+	rtnl_unlock();
 	kfree(tn->idrinfo);
 }
 
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index da6fa82..ca2ff0b 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -78,6 +78,7 @@
 	spin_lock_bh(&idrinfo->lock);
 	idr_remove_ext(&idrinfo->action_idr, p->tcfa_index);
 	spin_unlock_bh(&idrinfo->lock);
+	put_net(idrinfo->net);
 	gen_kill_estimator(&p->tcfa_rate_est);
 	free_tcf(p);
 }
@@ -86,6 +87,8 @@
 {
 	int ret = 0;
 
+	ASSERT_RTNL();
+
 	if (p) {
 		if (bind)
 			p->tcfa_bindcnt--;
@@ -334,6 +337,7 @@
 	p->idrinfo = idrinfo;
 	p->ops = ops;
 	INIT_LIST_HEAD(&p->list);
+	get_net(idrinfo->net);
 	*a = p;
 	return 0;
 }
diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c
index c0c707e..9bce8cc 100644
--- a/net/sched/act_bpf.c
+++ b/net/sched/act_bpf.c
@@ -398,7 +398,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, bpf_net_id);
 
-	return tc_action_net_init(tn, &act_bpf_ops);
+	return tc_action_net_init(tn, &act_bpf_ops, net);
 }
 
 static void __net_exit bpf_exit_net(struct net *net)
diff --git a/net/sched/act_connmark.c b/net/sched/act_connmark.c
index 10b7a88..34e52d0 100644
--- a/net/sched/act_connmark.c
+++ b/net/sched/act_connmark.c
@@ -206,7 +206,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, connmark_net_id);
 
-	return tc_action_net_init(tn, &act_connmark_ops);
+	return tc_action_net_init(tn, &act_connmark_ops, net);
 }
 
 static void __net_exit connmark_exit_net(struct net *net)
diff --git a/net/sched/act_csum.c b/net/sched/act_csum.c
index 1c40caa..35171df 100644
--- a/net/sched/act_csum.c
+++ b/net/sched/act_csum.c
@@ -626,7 +626,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, csum_net_id);
 
-	return tc_action_net_init(tn, &act_csum_ops);
+	return tc_action_net_init(tn, &act_csum_ops, net);
 }
 
 static void __net_exit csum_exit_net(struct net *net)
diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c
index e29a48e..ef7f7f3 100644
--- a/net/sched/act_gact.c
+++ b/net/sched/act_gact.c
@@ -232,7 +232,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, gact_net_id);
 
-	return tc_action_net_init(tn, &act_gact_ops);
+	return tc_action_net_init(tn, &act_gact_ops, net);
 }
 
 static void __net_exit gact_exit_net(struct net *net)
diff --git a/net/sched/act_ife.c b/net/sched/act_ife.c
index 8ccd358..f65e4b5 100644
--- a/net/sched/act_ife.c
+++ b/net/sched/act_ife.c
@@ -818,7 +818,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, ife_net_id);
 
-	return tc_action_net_init(tn, &act_ife_ops);
+	return tc_action_net_init(tn, &act_ife_ops, net);
 }
 
 static void __net_exit ife_exit_net(struct net *net)
diff --git a/net/sched/act_ipt.c b/net/sched/act_ipt.c
index d9e399a..dbdf3b2 100644
--- a/net/sched/act_ipt.c
+++ b/net/sched/act_ipt.c
@@ -334,7 +334,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, ipt_net_id);
 
-	return tc_action_net_init(tn, &act_ipt_ops);
+	return tc_action_net_init(tn, &act_ipt_ops, net);
 }
 
 static void __net_exit ipt_exit_net(struct net *net)
@@ -384,7 +384,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, xt_net_id);
 
-	return tc_action_net_init(tn, &act_xt_ops);
+	return tc_action_net_init(tn, &act_xt_ops, net);
 }
 
 static void __net_exit xt_exit_net(struct net *net)
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
index 416627c..84759cf 100644
--- a/net/sched/act_mirred.c
+++ b/net/sched/act_mirred.c
@@ -343,7 +343,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, mirred_net_id);
 
-	return tc_action_net_init(tn, &act_mirred_ops);
+	return tc_action_net_init(tn, &act_mirred_ops, net);
 }
 
 static void __net_exit mirred_exit_net(struct net *net)
diff --git a/net/sched/act_nat.c b/net/sched/act_nat.c
index c365d01..7eeaaf9 100644
--- a/net/sched/act_nat.c
+++ b/net/sched/act_nat.c
@@ -307,7 +307,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, nat_net_id);
 
-	return tc_action_net_init(tn, &act_nat_ops);
+	return tc_action_net_init(tn, &act_nat_ops, net);
 }
 
 static void __net_exit nat_exit_net(struct net *net)
diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c
index 491fe5d..b3d82c3 100644
--- a/net/sched/act_pedit.c
+++ b/net/sched/act_pedit.c
@@ -450,7 +450,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, pedit_net_id);
 
-	return tc_action_net_init(tn, &act_pedit_ops);
+	return tc_action_net_init(tn, &act_pedit_ops, net);
 }
 
 static void __net_exit pedit_exit_net(struct net *net)
diff --git a/net/sched/act_police.c b/net/sched/act_police.c
index 3bb2ebf..9ec42b2 100644
--- a/net/sched/act_police.c
+++ b/net/sched/act_police.c
@@ -331,7 +331,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, police_net_id);
 
-	return tc_action_net_init(tn, &act_police_ops);
+	return tc_action_net_init(tn, &act_police_ops, net);
 }
 
 static void __net_exit police_exit_net(struct net *net)
diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c
index 8b5abcd..e69a1e3 100644
--- a/net/sched/act_sample.c
+++ b/net/sched/act_sample.c
@@ -240,7 +240,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, sample_net_id);
 
-	return tc_action_net_init(tn, &act_sample_ops);
+	return tc_action_net_init(tn, &act_sample_ops, net);
 }
 
 static void __net_exit sample_exit_net(struct net *net)
diff --git a/net/sched/act_simple.c b/net/sched/act_simple.c
index e7b57e5..a8d0ea9 100644
--- a/net/sched/act_simple.c
+++ b/net/sched/act_simple.c
@@ -201,7 +201,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, simp_net_id);
 
-	return tc_action_net_init(tn, &act_simp_ops);
+	return tc_action_net_init(tn, &act_simp_ops, net);
 }
 
 static void __net_exit simp_exit_net(struct net *net)
diff --git a/net/sched/act_skbedit.c b/net/sched/act_skbedit.c
index 59949d6..fbac624 100644
--- a/net/sched/act_skbedit.c
+++ b/net/sched/act_skbedit.c
@@ -238,7 +238,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 
-	return tc_action_net_init(tn, &act_skbedit_ops);
+	return tc_action_net_init(tn, &act_skbedit_ops, net);
 }
 
 static void __net_exit skbedit_exit_net(struct net *net)
diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
index b642ad3..8e12d88 100644
--- a/net/sched/act_skbmod.c
+++ b/net/sched/act_skbmod.c
@@ -263,7 +263,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, skbmod_net_id);
 
-	return tc_action_net_init(tn, &act_skbmod_ops);
+	return tc_action_net_init(tn, &act_skbmod_ops, net);
 }
 
 static void __net_exit skbmod_exit_net(struct net *net)
diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c
index 30c9627..c33faa3 100644
--- a/net/sched/act_tunnel_key.c
+++ b/net/sched/act_tunnel_key.c
@@ -322,7 +322,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
 
-	return tc_action_net_init(tn, &act_tunnel_key_ops);
+	return tc_action_net_init(tn, &act_tunnel_key_ops, net);
 }
 
 static void __net_exit tunnel_key_exit_net(struct net *net)
diff --git a/net/sched/act_vlan.c b/net/sched/act_vlan.c
index 16eb067..115fc33 100644
--- a/net/sched/act_vlan.c
+++ b/net/sched/act_vlan.c
@@ -269,7 +269,7 @@
 {
 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
 
-	return tc_action_net_init(tn, &act_vlan_ops);
+	return tc_action_net_init(tn, &act_vlan_ops, net);
 }
 
 static void __net_exit vlan_exit_net(struct net *net)