1 files changed, 13 insertions, 19 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 76c2dca7f0a5..5bd409ab4cc2 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -49,6 +49,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/ethtool.h>
+#include <linux/filter.h>
 #include <linux/types.h>
 #include <linux/mm.h>
 #include <linux/capability.h>
@@ -3102,16 +3103,14 @@ static int packet_release(struct socket *sock)
 	sk_del_node_init_rcu(sk);
 	mutex_unlock(&net->packet.sklist_lock);
 
-	preempt_disable();
 	sock_prot_inuse_add(net, sk->sk_prot, -1);
-	preempt_enable();
 
 	spin_lock(&po->bind_lock);
 	unregister_prot_hook(sk, false);
 	packet_cached_dev_reset(po);
 
 	if (po->prot_hook.dev) {
-		dev_put(po->prot_hook.dev);
+		dev_put_track(po->prot_hook.dev, &po->prot_hook.dev_tracker);
 		po->prot_hook.dev = NULL;
 	}
 	spin_unlock(&po->bind_lock);
@@ -3163,12 +3162,10 @@ static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
 			  __be16 proto)
 {
 	struct packet_sock *po = pkt_sk(sk);
-	struct net_device *dev_curr;
-	__be16 proto_curr;
-	bool need_rehook;
 	struct net_device *dev = NULL;
-	int ret = 0;
 	bool unlisted = false;
+	bool need_rehook;
+	int ret = 0;
 
 	lock_sock(sk);
 	spin_lock(&po->bind_lock);
@@ -3193,14 +3190,10 @@ static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
 		}
 	}
 
-	dev_hold(dev);
-
-	proto_curr = po->prot_hook.type;
-	dev_curr = po->prot_hook.dev;
-
-	need_rehook = proto_curr != proto || dev_curr != dev;
+	need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev;
 
 	if (need_rehook) {
+		dev_hold(dev);
 		if (po->running) {
 			rcu_read_unlock();
 			/* prevents packet_notifier() from calling
@@ -3209,7 +3202,6 @@ static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
 			WRITE_ONCE(po->num, 0);
 			__unregister_prot_hook(sk, true);
 			rcu_read_lock();
-			dev_curr = po->prot_hook.dev;
 			if (dev)
 				unlisted = !dev_get_by_index_rcu(sock_net(sk),
 								 dev->ifindex);
@@ -3219,18 +3211,21 @@ static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
 		WRITE_ONCE(po->num, proto);
 		po->prot_hook.type = proto;
 
+		dev_put_track(po->prot_hook.dev, &po->prot_hook.dev_tracker);
+
 		if (unlikely(unlisted)) {
-			dev_put(dev);
 			po->prot_hook.dev = NULL;
 			WRITE_ONCE(po->ifindex, -1);
 			packet_cached_dev_reset(po);
 		} else {
+			dev_hold_track(dev, &po->prot_hook.dev_tracker,
+				       GFP_ATOMIC);
 			po->prot_hook.dev = dev;
 			WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0);
 			packet_cached_dev_assign(po, dev);
 		}
+		dev_put(dev);
 	}
-	dev_put(dev_curr);
 
 	if (proto == 0 || !need_rehook)
 		goto out_unlock;
@@ -3368,9 +3363,7 @@ static int packet_create(struct net *net, struct socket *sock, int protocol,
 	sk_add_node_tail_rcu(sk, &net->packet.sklist);
 	mutex_unlock(&net->packet.sklist_lock);
 
-	preempt_disable();
 	sock_prot_inuse_add(net, &packet_proto, 1);
-	preempt_enable();
 
 	return 0;
 out2:
@@ -4142,7 +4135,8 @@ static int packet_notifier(struct notifier_block *this,
 				if (msg == NETDEV_UNREGISTER) {
 					packet_cached_dev_reset(po);
 					WRITE_ONCE(po->ifindex, -1);
-					dev_put(po->prot_hook.dev);
+					dev_put_track(po->prot_hook.dev,
+						      &po->prot_hook.dev_tracker);
 					po->prot_hook.dev = NULL;
 				}
 				spin_unlock(&po->bind_lock);