diff options
| -rw-r--r-- | net/packet/af_packet.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 85ea7ddb48db..ab87f22cc7ec 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1789,7 +1789,10 @@ static int fanout_add(struct sock *sk, struct fanout_args *args) err = -ENOSPC; if (refcount_read(&match->sk_ref) < match->max_num_members) { __dev_remove_pack(&po->prot_hook); - po->fanout = match; + + /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */ + WRITE_ONCE(po->fanout, match); + po->rollover = rollover; rollover = NULL; refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1); @@ -3934,7 +3937,8 @@ packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, } case PACKET_FANOUT_DATA: { - if (!po->fanout) + /* Paired with the WRITE_ONCE() in fanout_add() */ + if (!READ_ONCE(po->fanout)) return -EINVAL; return fanout_set_data(po, optval, optlen); |