1 files changed, 15 insertions, 22 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 737092ca9b4e..da215e5c1399 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1687,7 +1687,6 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
 		atomic_long_set(&rollover->num, 0);
 		atomic_long_set(&rollover->num_huge, 0);
 		atomic_long_set(&rollover->num_failed, 0);
-		po->rollover = rollover;
 	}
 
 	if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
@@ -1745,6 +1744,8 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
 		if (refcount_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
 			__dev_remove_pack(&po->prot_hook);
 			po->fanout = match;
+			po->rollover = rollover;
+			rollover = NULL;
 			refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
 			__fanout_link(sk, po);
 			err = 0;
@@ -1758,10 +1759,7 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
 	}
 
 out:
-	if (err && rollover) {
-		kfree_rcu(rollover, rcu);
-		po->rollover = NULL;
-	}
+	kfree(rollover);
 	mutex_unlock(&fanout_mutex);
 	return err;
 }
@@ -1785,11 +1783,6 @@ static struct packet_fanout *fanout_release(struct sock *sk)
 			list_del(&f->list);
 		else
 			f = NULL;
-
-		if (po->rollover) {
-			kfree_rcu(po->rollover, rcu);
-			po->rollover = NULL;
-		}
 	}
 	mutex_unlock(&fanout_mutex);
 
@@ -3029,6 +3022,7 @@ static int packet_release(struct socket *sock)
 	synchronize_net();
 
 	if (f) {
+		kfree(po->rollover);
 		fanout_release_data(f);
 		kfree(f);
 	}
@@ -3097,6 +3091,10 @@ static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
 	if (need_rehook) {
 		if (po->running) {
 			rcu_read_unlock();
+			/* prevents packet_notifier() from calling
+			 * register_prot_hook()
+			 */
+			po->num = 0;
 			__unregister_prot_hook(sk, true);
 			rcu_read_lock();
 			dev_curr = po->prot_hook.dev;
@@ -3105,6 +3103,7 @@ static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
 								 dev->ifindex);
 		}
 
+		BUG_ON(po->running);
 		po->num = proto;
 		po->prot_hook.type = proto;
 
@@ -3843,7 +3842,6 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
 	void *data = &val;
 	union tpacket_stats_u st;
 	struct tpacket_rollover_stats rstats;
-	struct packet_rollover *rollover;
 
 	if (level != SOL_PACKET)
 		return -ENOPROTOOPT;
@@ -3922,18 +3920,13 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
 		       0);
 		break;
 	case PACKET_ROLLOVER_STATS:
-		rcu_read_lock();
-		rollover = rcu_dereference(po->rollover);
-		if (rollover) {
-			rstats.tp_all = atomic_long_read(&rollover->num);
-			rstats.tp_huge = atomic_long_read(&rollover->num_huge);
-			rstats.tp_failed = atomic_long_read(&rollover->num_failed);
-			data = &rstats;
-			lv = sizeof(rstats);
-		}
-		rcu_read_unlock();
-		if (!rollover)
+		if (!po->rollover)
 			return -EINVAL;
+		rstats.tp_all = atomic_long_read(&po->rollover->num);
+		rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
+		rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
+		data = &rstats;
+		lv = sizeof(rstats);
 		break;
 	case PACKET_TX_HAS_OFF:
 		val = po->tp_tx_has_off;