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-rw-r--r--net/packet/af_packet.c31
1 files changed, 22 insertions, 9 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 0f03f6a53b4d..70f5b6a4683c 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1497,6 +1497,8 @@ static void __fanout_link(struct sock *sk, struct packet_sock *po)
f->arr[f->num_members] = sk;
smp_wmb();
f->num_members++;
+ if (f->num_members == 1)
+ dev_add_pack(&f->prot_hook);
spin_unlock(&f->lock);
}
@@ -1513,6 +1515,8 @@ static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
BUG_ON(i >= f->num_members);
f->arr[i] = f->arr[f->num_members - 1];
f->num_members--;
+ if (f->num_members == 0)
+ __dev_remove_pack(&f->prot_hook);
spin_unlock(&f->lock);
}
@@ -1693,7 +1697,6 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
match->prot_hook.func = packet_rcv_fanout;
match->prot_hook.af_packet_priv = match;
match->prot_hook.id_match = match_fanout_group;
- dev_add_pack(&match->prot_hook);
list_add(&match->list, &fanout_list);
}
err = -EINVAL;
@@ -1718,7 +1721,12 @@ out:
return err;
}
-static void fanout_release(struct sock *sk)
+/* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
+ * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
+ * It is the responsibility of the caller to call fanout_release_data() and
+ * free the returned packet_fanout (after synchronize_net())
+ */
+static struct packet_fanout *fanout_release(struct sock *sk)
{
struct packet_sock *po = pkt_sk(sk);
struct packet_fanout *f;
@@ -1728,17 +1736,17 @@ static void fanout_release(struct sock *sk)
if (f) {
po->fanout = NULL;
- if (atomic_dec_and_test(&f->sk_ref)) {
+ if (atomic_dec_and_test(&f->sk_ref))
list_del(&f->list);
- dev_remove_pack(&f->prot_hook);
- fanout_release_data(f);
- kfree(f);
- }
+ else
+ f = NULL;
if (po->rollover)
kfree_rcu(po->rollover, rcu);
}
mutex_unlock(&fanout_mutex);
+
+ return f;
}
static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
@@ -2912,6 +2920,7 @@ static int packet_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct packet_sock *po;
+ struct packet_fanout *f;
struct net *net;
union tpacket_req_u req_u;
@@ -2951,9 +2960,14 @@ static int packet_release(struct socket *sock)
packet_set_ring(sk, &req_u, 1, 1);
}
- fanout_release(sk);
+ f = fanout_release(sk);
synchronize_net();
+
+ if (f) {
+ fanout_release_data(f);
+ kfree(f);
+ }
/*
* Now the socket is dead. No more input will appear.
*/
@@ -3905,7 +3919,6 @@ static int packet_notifier(struct notifier_block *this,
}
if (msg == NETDEV_UNREGISTER) {
packet_cached_dev_reset(po);
- fanout_release(sk);
po->ifindex = -1;
if (po->prot_hook.dev)
dev_put(po->prot_hook.dev);